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Select the correct pair:- a) Vitamin B1 - Beriberi
- b) Vitamin A - Rickets
- c) Vitamin C - Goiter
- d) Vitamin D - Anaemia
Correct answer is option 'A'. Can you explain this answer?
Select the correct pair:
a)
Vitamin B1 - Beriberi
b)
Vitamin A - Rickets
c)
Vitamin C - Goiter
d)
Vitamin D - Anaemia
|
Aman Choudhury answered |
Vitamins and Their Deficiency Diseases
Vitamins are essential nutrients required by our body in small amounts for various physiological functions. A lack of vitamins in our diet leads to various deficiency diseases. Let's understand the correct pair of vitamins and their deficiency diseases.
Correct Pair
Vitamin B1 - Beriberi
Thiamine or Vitamin B1 is essential for the proper functioning of the nervous system, muscles, and heart. It helps in the breakdown of carbohydrates and provides energy to the body. A deficiency of Vitamin B1 leads to a disease called Beriberi. Beriberi is a neurological and cardiovascular disorder that affects the nervous system and the heart. It is characterized by muscle weakness, loss of sensation in hands and feet, and heart failure.
Incorrect Pairs
b)Vitamin A - Rickets
Vitamin A is essential for maintaining healthy eyesight, skin, and immune system. It is not related to Rickets. Rickets is a deficiency disease of Vitamin D. Vitamin D is important for the absorption of calcium and phosphorus in the body. A deficiency of Vitamin D leads to Rickets, which is characterized by weak and soft bones, bowed legs, and stunted growth.
c)Vitamin C - Goiter
Vitamin C or Ascorbic acid is important for the growth and repair of tissues in the body. It also helps in the absorption of iron and boosts the immune system. It is not related to Goiter. Goiter is a condition where the thyroid gland in the neck becomes enlarged due to the deficiency of iodine. Iodine is required for the synthesis of thyroid hormones.
d)Vitamin D - Anaemia
Vitamin D is important for the absorption of calcium and phosphorus in the body. It is not related to Anaemia. Anaemia is a condition where there is a deficiency of red blood cells or haemoglobin in the blood. Iron and Vitamin B12 are important for the production of red blood cells. A deficiency of these nutrients leads to Anaemia.
Conclusion
Hence, the correct pair of vitamins and their deficiency disease is Vitamin B1 - Beriberi. It is important to include a balanced diet with all the essential vitamins and minerals to prevent any deficiency disease.
Vitamins are essential nutrients required by our body in small amounts for various physiological functions. A lack of vitamins in our diet leads to various deficiency diseases. Let's understand the correct pair of vitamins and their deficiency diseases.
Correct Pair
Vitamin B1 - Beriberi
Thiamine or Vitamin B1 is essential for the proper functioning of the nervous system, muscles, and heart. It helps in the breakdown of carbohydrates and provides energy to the body. A deficiency of Vitamin B1 leads to a disease called Beriberi. Beriberi is a neurological and cardiovascular disorder that affects the nervous system and the heart. It is characterized by muscle weakness, loss of sensation in hands and feet, and heart failure.
Incorrect Pairs
b)Vitamin A - Rickets
Vitamin A is essential for maintaining healthy eyesight, skin, and immune system. It is not related to Rickets. Rickets is a deficiency disease of Vitamin D. Vitamin D is important for the absorption of calcium and phosphorus in the body. A deficiency of Vitamin D leads to Rickets, which is characterized by weak and soft bones, bowed legs, and stunted growth.
c)Vitamin C - Goiter
Vitamin C or Ascorbic acid is important for the growth and repair of tissues in the body. It also helps in the absorption of iron and boosts the immune system. It is not related to Goiter. Goiter is a condition where the thyroid gland in the neck becomes enlarged due to the deficiency of iodine. Iodine is required for the synthesis of thyroid hormones.
d)Vitamin D - Anaemia
Vitamin D is important for the absorption of calcium and phosphorus in the body. It is not related to Anaemia. Anaemia is a condition where there is a deficiency of red blood cells or haemoglobin in the blood. Iron and Vitamin B12 are important for the production of red blood cells. A deficiency of these nutrients leads to Anaemia.
Conclusion
Hence, the correct pair of vitamins and their deficiency disease is Vitamin B1 - Beriberi. It is important to include a balanced diet with all the essential vitamins and minerals to prevent any deficiency disease.
Which of the following is not a form of precipitation?- a)Snow
- b)Rain
- c)Hailstone
- d)None of them
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not a form of precipitation?
a)
Snow
b)
Rain
c)
Hailstone
d)
None of them
|
Arjun Yadav answered |
The correct answer is option 'D' - None of them.
Precipitation refers to any form of water that falls from the atmosphere and reaches the Earth's surface. It includes various forms such as rain, snow, sleet, and hail. Let's discuss each of these forms of precipitation to understand why option 'D' is the correct answer.
1. **Rain**: Rain is the most common form of precipitation. It occurs when water droplets in clouds combine and become heavy enough to fall to the ground. Raindrops can vary in size from small drizzles to heavy downpours.
2. **Snow**: Snow is another form of precipitation that occurs when the temperature in the atmosphere is below freezing point. Water vapor in the clouds freezes into ice crystals, which then come together to form snowflakes. Snowflakes are unique in shape and can accumulate on the ground, creating a layer of snow.
3. **Hailstone**: Hailstones are balls or irregular lumps of ice that form in severe thunderstorms. They are different from other forms of precipitation as they are solid rather than liquid. Hailstones are formed when there are strong updrafts in the storm clouds, causing raindrops to be carried upwards into extremely cold regions of the cloud. The raindrops freeze into ice pellets, and as they are carried up and down by strong air currents, additional layers of ice are added, making the hailstone grow larger. Eventually, the hailstones become too heavy for the updrafts to support, and they fall to the ground.
Now, considering the options given, all of them - snow, rain, and hailstone - are forms of precipitation. Therefore, the correct answer is option 'D' - None of them.
Precipitation refers to any form of water that falls from the atmosphere and reaches the Earth's surface. It includes various forms such as rain, snow, sleet, and hail. Let's discuss each of these forms of precipitation to understand why option 'D' is the correct answer.
1. **Rain**: Rain is the most common form of precipitation. It occurs when water droplets in clouds combine and become heavy enough to fall to the ground. Raindrops can vary in size from small drizzles to heavy downpours.
2. **Snow**: Snow is another form of precipitation that occurs when the temperature in the atmosphere is below freezing point. Water vapor in the clouds freezes into ice crystals, which then come together to form snowflakes. Snowflakes are unique in shape and can accumulate on the ground, creating a layer of snow.
3. **Hailstone**: Hailstones are balls or irregular lumps of ice that form in severe thunderstorms. They are different from other forms of precipitation as they are solid rather than liquid. Hailstones are formed when there are strong updrafts in the storm clouds, causing raindrops to be carried upwards into extremely cold regions of the cloud. The raindrops freeze into ice pellets, and as they are carried up and down by strong air currents, additional layers of ice are added, making the hailstone grow larger. Eventually, the hailstones become too heavy for the updrafts to support, and they fall to the ground.
Now, considering the options given, all of them - snow, rain, and hailstone - are forms of precipitation. Therefore, the correct answer is option 'D' - None of them.
Select the option the letters of which, on reshuffling, will give the term given to describe water seepage into the ground.- a)Ntciepirtaipo
- b)Atooniaervp
- c)Aitfinlronit
- d)Tspratniaoinr
Correct answer is option 'C'. Can you explain this answer?
Select the option the letters of which, on reshuffling, will give the term given to describe water seepage into the ground.
a)
Ntciepirtaipo
b)
Atooniaervp
c)
Aitfinlronit
d)
Tspratniaoinr
|
Shubham Chakraborty answered |
Infiltration is the process by which water on the ground surface enters the soil. It is commonly used in both hydrology and soil sciences. The infiltration capacity is defined as the maximum rate of infiltration.
Which of the following actions will help in reducing pollution?
1. Restricting smoking in public areas
2. Treatment of sewage to remove human waste
3. Using unleaded petrol in cars
4. Spraying pesticides on paints to kill pests- a)1, 2 and 4
- b)1, 2 and 3
- c)1 and 2
- d)1 and 4
Correct answer is option 'B'. Can you explain this answer?
Which of the following actions will help in reducing pollution?
1. Restricting smoking in public areas
2. Treatment of sewage to remove human waste
3. Using unleaded petrol in cars
4. Spraying pesticides on paints to kill pests
1. Restricting smoking in public areas
2. Treatment of sewage to remove human waste
3. Using unleaded petrol in cars
4. Spraying pesticides on paints to kill pests
a)
1, 2 and 4
b)
1, 2 and 3
c)
1 and 2
d)
1 and 4
|
Kalyan Sengupta answered |
Explanation:
In order to reduce pollution, it is important to take various actions that can help in minimizing the release of harmful pollutants into the environment. The correct answer is option B, which includes actions 1, 2, and 3. Let's discuss each action in detail:
1. Restricting smoking in public areas:
- Smoking releases a significant amount of harmful chemicals and pollutants into the air, such as carbon monoxide, nitrogen oxides, and particulate matter.
- Restricting smoking in public areas helps in reducing exposure to secondhand smoke, protecting people from the harmful effects of smoking and preventing air pollution.
2. Treatment of sewage to remove human waste:
- Sewage contains human waste and various pollutants, including bacteria, viruses, and chemicals.
- Proper treatment of sewage involves removing solid waste, treating the water to remove harmful bacteria and chemicals, and disinfecting it before it is released back into the environment.
- Treatment of sewage helps in preventing water pollution and the spread of waterborne diseases.
3. Using unleaded petrol in cars:
- Leaded petrol contains a high level of lead, which is a toxic metal that can cause serious health problems, especially in children.
- Using unleaded petrol in cars helps in reducing the release of lead into the air, thereby minimizing air pollution and the associated health risks.
4. Spraying pesticides on paints to kill pests:
- This action is incorrect and should not be considered as a way to reduce pollution.
- Spraying pesticides on paints can introduce harmful chemicals into the environment, which can contribute to air and water pollution.
- Additionally, the use of pesticides can have negative effects on human health and the ecosystem, as they can harm beneficial insects and animals.
To summarize, actions 1, 2, and 3 are effective in reducing pollution, while action 4 can actually contribute to pollution. Therefore, option B, which includes actions 1, 2, and 3, is the correct answer.
In order to reduce pollution, it is important to take various actions that can help in minimizing the release of harmful pollutants into the environment. The correct answer is option B, which includes actions 1, 2, and 3. Let's discuss each action in detail:
1. Restricting smoking in public areas:
- Smoking releases a significant amount of harmful chemicals and pollutants into the air, such as carbon monoxide, nitrogen oxides, and particulate matter.
- Restricting smoking in public areas helps in reducing exposure to secondhand smoke, protecting people from the harmful effects of smoking and preventing air pollution.
2. Treatment of sewage to remove human waste:
- Sewage contains human waste and various pollutants, including bacteria, viruses, and chemicals.
- Proper treatment of sewage involves removing solid waste, treating the water to remove harmful bacteria and chemicals, and disinfecting it before it is released back into the environment.
- Treatment of sewage helps in preventing water pollution and the spread of waterborne diseases.
3. Using unleaded petrol in cars:
- Leaded petrol contains a high level of lead, which is a toxic metal that can cause serious health problems, especially in children.
- Using unleaded petrol in cars helps in reducing the release of lead into the air, thereby minimizing air pollution and the associated health risks.
4. Spraying pesticides on paints to kill pests:
- This action is incorrect and should not be considered as a way to reduce pollution.
- Spraying pesticides on paints can introduce harmful chemicals into the environment, which can contribute to air and water pollution.
- Additionally, the use of pesticides can have negative effects on human health and the ecosystem, as they can harm beneficial insects and animals.
To summarize, actions 1, 2, and 3 are effective in reducing pollution, while action 4 can actually contribute to pollution. Therefore, option B, which includes actions 1, 2, and 3, is the correct answer.
Light is a form of energy produced by a- a)Luminous object
- b)Transparent object
- c)Non-luminous object
- d)Opaque object
Correct answer is option 'A'. Can you explain this answer?
Light is a form of energy produced by a
a)
Luminous object
b)
Transparent object
c)
Non-luminous object
d)
Opaque object
|
Muskaan Chavan answered |
Light is a form of energy produced by a luminous object.
Light is a type of energy that allows us to see objects around us. It is produced by certain objects called luminous objects. These objects have the ability to emit their own light. Let's understand this concept in more detail:
1. Luminous objects:
- Luminous objects are objects that produce their own light.
- They have a property called luminosity, which refers to their ability to emit light.
- Examples of luminous objects include the Sun, stars, light bulbs, and fireflies.
- These objects have a source of energy that causes the atoms and molecules within them to become excited and emit light as a result.
2. Transparent objects:
- Transparent objects are objects that allow light to pass through them easily.
- They do not produce their own light but can transmit light from a luminous object to our eyes.
- Examples of transparent objects include glass, air, and water.
- When light passes through a transparent object, it does not change its direction significantly and allows us to see objects on the other side.
3. Non-luminous objects:
- Non-luminous objects are objects that do not produce their own light.
- They cannot emit light but can reflect or absorb light from a luminous object.
- Examples of non-luminous objects include books, tables, and chairs.
- These objects are visible to us because they reflect light from a luminous object or from a light source like a light bulb.
4. Opaque objects:
- Opaque objects are objects that do not allow light to pass through them.
- They neither produce their own light nor transmit light through them.
- Examples of opaque objects include walls, wood, and metals.
- When light falls on an opaque object, it is either reflected or absorbed by the object, making it difficult for light to pass through.
Therefore, light is produced by luminous objects, which have the ability to emit their own light. Transparent objects allow light to pass through, non-luminous objects reflect or absorb light, and opaque objects do not allow light to pass through them.
Light is a type of energy that allows us to see objects around us. It is produced by certain objects called luminous objects. These objects have the ability to emit their own light. Let's understand this concept in more detail:
1. Luminous objects:
- Luminous objects are objects that produce their own light.
- They have a property called luminosity, which refers to their ability to emit light.
- Examples of luminous objects include the Sun, stars, light bulbs, and fireflies.
- These objects have a source of energy that causes the atoms and molecules within them to become excited and emit light as a result.
2. Transparent objects:
- Transparent objects are objects that allow light to pass through them easily.
- They do not produce their own light but can transmit light from a luminous object to our eyes.
- Examples of transparent objects include glass, air, and water.
- When light passes through a transparent object, it does not change its direction significantly and allows us to see objects on the other side.
3. Non-luminous objects:
- Non-luminous objects are objects that do not produce their own light.
- They cannot emit light but can reflect or absorb light from a luminous object.
- Examples of non-luminous objects include books, tables, and chairs.
- These objects are visible to us because they reflect light from a luminous object or from a light source like a light bulb.
4. Opaque objects:
- Opaque objects are objects that do not allow light to pass through them.
- They neither produce their own light nor transmit light through them.
- Examples of opaque objects include walls, wood, and metals.
- When light falls on an opaque object, it is either reflected or absorbed by the object, making it difficult for light to pass through.
Therefore, light is produced by luminous objects, which have the ability to emit their own light. Transparent objects allow light to pass through, non-luminous objects reflect or absorb light, and opaque objects do not allow light to pass through them.
Rearrange the following letters to make a single word and then choose the category to which it belongs:Y L A T I- a)Country
- b)Ocean
- c)City
- d)Mountain
Correct answer is option 'A'. Can you explain this answer?
Rearrange the following letters to make a single word and then choose the category to which it belongs:
Y L A T I
a)
Country
b)
Ocean
c)
City
d)
Mountain
|
Muskaan Joshi answered |
Answer:
To rearrange the letters "Y L A T I" into a single word, we can form the word "ITALY".
Explanation:
The word "ITALY" is the correct rearrangement of the given letters.
Category:
The word "ITALY" belongs to the category of countries.
To rearrange the letters "Y L A T I" into a single word, we can form the word "ITALY".
Explanation:
The word "ITALY" is the correct rearrangement of the given letters.
Category:
The word "ITALY" belongs to the category of countries.
Decantation process is used to separate:- a)Two immiscible liquids
- b)Two miscible liquids
- c)Two metals in an alloy
- d)Solid-solid mixture
Correct answer is option 'A'. Can you explain this answer?
Decantation process is used to separate:
a)
Two immiscible liquids
b)
Two miscible liquids
c)
Two metals in an alloy
d)
Solid-solid mixture
|
Jyoti Kaur answered |
Decantation Process
Decantation is a process used to separate two immiscible liquids, i.e., liquids that do not mix together. This method is based on the principle that immiscible liquids have different densities, allowing them to separate naturally when left undisturbed.
Procedure
- The two immiscible liquids are allowed to settle in a container.
- Once settled, the heavier liquid (having higher density) settles at the bottom, while the lighter liquid (having lower density) forms a separate layer on top.
- The container is then tilted carefully, and the lighter liquid is poured out slowly without disturbing the heavier liquid layer. This process is known as decantation.
Example
For example, if a mixture of water and oil is left to stand, the oil, being less dense, will float on top of the water. By carefully pouring off the oil without disturbing the water layer beneath, the two liquids can be separated using decantation.
Significance
Decantation is a simple and effective method for separating immiscible liquids without the need for complex equipment or chemicals. It is commonly used in various industries such as food processing, pharmaceuticals, and wastewater treatment.
Decantation is a process used to separate two immiscible liquids, i.e., liquids that do not mix together. This method is based on the principle that immiscible liquids have different densities, allowing them to separate naturally when left undisturbed.
Procedure
- The two immiscible liquids are allowed to settle in a container.
- Once settled, the heavier liquid (having higher density) settles at the bottom, while the lighter liquid (having lower density) forms a separate layer on top.
- The container is then tilted carefully, and the lighter liquid is poured out slowly without disturbing the heavier liquid layer. This process is known as decantation.
Example
For example, if a mixture of water and oil is left to stand, the oil, being less dense, will float on top of the water. By carefully pouring off the oil without disturbing the water layer beneath, the two liquids can be separated using decantation.
Significance
Decantation is a simple and effective method for separating immiscible liquids without the need for complex equipment or chemicals. It is commonly used in various industries such as food processing, pharmaceuticals, and wastewater treatment.
A is the father of B and C is the mother of D. M is the paternal uncle of D. If B and D are siblings, then how is M related to A?- a)Father
- b)Brother
- c)Uncle
- d)Son
Correct answer is option 'B'. Can you explain this answer?
A is the father of B and C is the mother of D. M is the paternal uncle of D. If B and D are siblings, then how is M related to A?
a)
Father
b)
Brother
c)
Uncle
d)
Son
|
|
Aditya Menon answered |
Family Relationships Explained
Understanding family relationships can sometimes be tricky. Let’s break down the information given in this problem to clarify how M is related to A.
Key Relationships
- A is the father of B: This indicates that A is the parent of B.
- C is the mother of D: C is a separate parent, indicating that D is not a child of A.
- M is the paternal uncle of D: This means that M is the brother of A (since a paternal uncle is the brother of one of the child's parents).
- B and D are siblings: This means that B and D share at least one parent. Since B is A's child, it follows that D must also be A's child. Therefore, A is also D's parent, making C D's mother.
Connecting the Dots
- Since D is the child of A and C, and M is identified as the paternal uncle of D, it confirms that M is the brother of A.
- This establishes that M is related to A as his sibling.
Conclusion
Thus, the relationship can be summarized as follows:
- M is A's brother.
Therefore, the correct answer is option 'B' (Brother).
Understanding family relationships can sometimes be tricky. Let’s break down the information given in this problem to clarify how M is related to A.
Key Relationships
- A is the father of B: This indicates that A is the parent of B.
- C is the mother of D: C is a separate parent, indicating that D is not a child of A.
- M is the paternal uncle of D: This means that M is the brother of A (since a paternal uncle is the brother of one of the child's parents).
- B and D are siblings: This means that B and D share at least one parent. Since B is A's child, it follows that D must also be A's child. Therefore, A is also D's parent, making C D's mother.
Connecting the Dots
- Since D is the child of A and C, and M is identified as the paternal uncle of D, it confirms that M is the brother of A.
- This establishes that M is related to A as his sibling.
Conclusion
Thus, the relationship can be summarized as follows:
- M is A's brother.
Therefore, the correct answer is option 'B' (Brother).
Which two signs should be interchanged to make the equation correct?6 + (9 - 3) ÷ (8 + 1) × (7 - 4) = 24- a)× and ÷
- b)+ and ÷
- c)- and ÷
- d)+ and -
Correct answer is option 'A'. Can you explain this answer?
Which two signs should be interchanged to make the equation correct?
6 + (9 - 3) ÷ (8 + 1) × (7 - 4) = 24
a)
× and ÷
b)
+ and ÷
c)
- and ÷
d)
+ and -
|
Rounak Chawla answered |
Understanding the Original Equation
The original equation is:
6 + (9 - 3) ÷ (8 + 1) × (7 - 4) = 24
Let's break this down step by step.
Calculating Each Component
- (9 - 3) = 6
- (8 + 1) = 9
- (7 - 4) = 3
Now, substituting these values back into the equation:
6 + 6 ÷ 9 × 3
Order of Operations (BODMAS)
According to the order of operations (BODMAS/BIDMAS), we perform division and multiplication before addition:
1. 6 ÷ 9 = 2/3
2. (2/3) × 3 = 2
Now we rewrite the equation:
6 + 2 = 8
This is not equal to 24, indicating that we need to interchange some signs.
Identifying the Interchange
The goal is to find two signs to swap that will make the equation true.
If we swap the + and ÷, the equation will become:
6 ÷ (9 - 3) + (8 + 1) × (7 - 4)
Now calculating this:
1. (9 - 3) = 6
2. (8 + 1) = 9
3. (7 - 4) = 3
Substituting gives us:
6 ÷ 6 + 9 × 3
Now, applying order of operations:
1. 6 ÷ 6 = 1
2. 9 × 3 = 27
Now the equation reads:
1 + 27 = 28
This is still not correct.
Correct Swap for the Solution
By interchanging the signs × and ÷, the equation turns into:
6 + (9 - 3) × (8 + 1) ÷ (7 - 4)
Calculating this gives:
1. (9 - 3) = 6
2. (8 + 1) = 9
3. (7 - 4) = 3
The equation now reads:
6 + 6 × 9 ÷ 3
Following the order of operations:
1. 6 × 9 = 54
2. 54 ÷ 3 = 18
Finally:
6 + 18 = 24
Conclusion
Thus, the correct answer is to interchange × and ÷ (Option A) to make the equation true.
The original equation is:
6 + (9 - 3) ÷ (8 + 1) × (7 - 4) = 24
Let's break this down step by step.
Calculating Each Component
- (9 - 3) = 6
- (8 + 1) = 9
- (7 - 4) = 3
Now, substituting these values back into the equation:
6 + 6 ÷ 9 × 3
Order of Operations (BODMAS)
According to the order of operations (BODMAS/BIDMAS), we perform division and multiplication before addition:
1. 6 ÷ 9 = 2/3
2. (2/3) × 3 = 2
Now we rewrite the equation:
6 + 2 = 8
This is not equal to 24, indicating that we need to interchange some signs.
Identifying the Interchange
The goal is to find two signs to swap that will make the equation true.
If we swap the + and ÷, the equation will become:
6 ÷ (9 - 3) + (8 + 1) × (7 - 4)
Now calculating this:
1. (9 - 3) = 6
2. (8 + 1) = 9
3. (7 - 4) = 3
Substituting gives us:
6 ÷ 6 + 9 × 3
Now, applying order of operations:
1. 6 ÷ 6 = 1
2. 9 × 3 = 27
Now the equation reads:
1 + 27 = 28
This is still not correct.
Correct Swap for the Solution
By interchanging the signs × and ÷, the equation turns into:
6 + (9 - 3) × (8 + 1) ÷ (7 - 4)
Calculating this gives:
1. (9 - 3) = 6
2. (8 + 1) = 9
3. (7 - 4) = 3
The equation now reads:
6 + 6 × 9 ÷ 3
Following the order of operations:
1. 6 × 9 = 54
2. 54 ÷ 3 = 18
Finally:
6 + 18 = 24
Conclusion
Thus, the correct answer is to interchange × and ÷ (Option A) to make the equation true.
Which of the following statement(s) about saliva is/are true?- a)Saliva helps to digest food
- b)Saliva causes food to be rolled into a ball
- c)Saliva moistens the food to make swallowing easier
- d)A and C both
Correct answer is option 'D'. Can you explain this answer?
Which of the following statement(s) about saliva is/are true?
a)
Saliva helps to digest food
b)
Saliva causes food to be rolled into a ball
c)
Saliva moistens the food to make swallowing easier
d)
A and C both
|
Samriddha Nayan Gogoi answered |
The correct answer is option D as we never feel a ball in our mouth, do we? Obviously no, while saliva helps in the process of digestion and also softens the food present in our mouth.
Pigments of photosynthesis are present in which organelle of the plant cell?- a)Cytoplasm
- b)Chloroplast
- c)Nucleus
- d)Mitochondrion
Correct answer is option 'B'. Can you explain this answer?
Pigments of photosynthesis are present in which organelle of the plant cell?
a)
Cytoplasm
b)
Chloroplast
c)
Nucleus
d)
Mitochondrion
|
Rohini Seth answered |
In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.
If the the refractive index of any glass is 1, then which of the following statements is true regarding the glass?- a)The refracted ray will turn towards normal after refraction.
- b)The refracted ray will turn away from normal after refraction.
- c)The light will be partially reflected.
- d)The glass will become invisible.
Correct answer is option 'D'. Can you explain this answer?
If the the refractive index of any glass is 1, then which of the following statements is true regarding the glass?
a)
The refracted ray will turn towards normal after refraction.
b)
The refracted ray will turn away from normal after refraction.
c)
The light will be partially reflected.
d)
The glass will become invisible.
|
Dr Manju Sen answered |
As the refractive index it 1, the light will not go through any deviation. Hence, the glass will be invisible.
A young plant is seen to grow from the underground stem as shown below.
Q. The young plant gets its food from_____________ .- a)Its roots
- b)Its seeds
- c)The buds of the underground stem
- d)The food stored in the underground stem
Correct answer is option 'D'. Can you explain this answer?
A young plant is seen to grow from the underground stem as shown below.
Q. The young plant gets its food from_____________ .
a)
Its roots
b)
Its seeds
c)
The buds of the underground stem
d)
The food stored in the underground stem
|
|
Meena Yadav answered |
The foods stored in underground stem.
A plane mirror reflects a pencil of light to form a real image. Then the pencil of light incident on the mirror is:- a)Divergent
- b)Convergent
- c)Parallel
- d)None of them
Correct answer is option 'B'. Can you explain this answer?
A plane mirror reflects a pencil of light to form a real image. Then the pencil of light incident on the mirror is:
a)
Divergent
b)
Convergent
c)
Parallel
d)
None of them
|
Varun Jain answered |
**Explanation:**
A plane mirror reflects light in such a way that the incident light rays appear to originate from behind the mirror. This creates the illusion of a virtual image, which cannot be projected onto a screen. In the case of a real image, the light rays actually converge at a point and can be projected onto a screen.
**Divergent Light Rays:**
Divergent light rays are those that spread out as they propagate. They are typically produced by a light source that emits light in all directions, such as a candle flame or a light bulb. Divergent light rays do not converge and therefore cannot form a real image.
**Convergent Light Rays:**
Convergent light rays are those that come together or converge at a point. They are typically produced by a lens or a concave mirror. Convergent light rays can form a real image when they pass through a lens or are reflected by a concave mirror.
**Parallel Light Rays:**
Parallel light rays are those that propagate in straight lines without converging or diverging. They are typically produced by a distant light source, such as the Sun. Parallel light rays do not converge and therefore cannot form a real image.
**Application to the Plane Mirror:**
A plane mirror reflects light in such a way that the angles of incidence and reflection are equal. This means that the reflected rays are parallel to the incident rays. Since parallel rays do not converge, a plane mirror cannot form a real image.
Therefore, the correct answer is option **B) Convergent**. A pencil of light incident on a plane mirror is not convergent, divergent, or parallel. It simply reflects off the mirror at the same angle as the incident angle, resulting in a virtual image.
A plane mirror reflects light in such a way that the incident light rays appear to originate from behind the mirror. This creates the illusion of a virtual image, which cannot be projected onto a screen. In the case of a real image, the light rays actually converge at a point and can be projected onto a screen.
**Divergent Light Rays:**
Divergent light rays are those that spread out as they propagate. They are typically produced by a light source that emits light in all directions, such as a candle flame or a light bulb. Divergent light rays do not converge and therefore cannot form a real image.
**Convergent Light Rays:**
Convergent light rays are those that come together or converge at a point. They are typically produced by a lens or a concave mirror. Convergent light rays can form a real image when they pass through a lens or are reflected by a concave mirror.
**Parallel Light Rays:**
Parallel light rays are those that propagate in straight lines without converging or diverging. They are typically produced by a distant light source, such as the Sun. Parallel light rays do not converge and therefore cannot form a real image.
**Application to the Plane Mirror:**
A plane mirror reflects light in such a way that the angles of incidence and reflection are equal. This means that the reflected rays are parallel to the incident rays. Since parallel rays do not converge, a plane mirror cannot form a real image.
Therefore, the correct answer is option **B) Convergent**. A pencil of light incident on a plane mirror is not convergent, divergent, or parallel. It simply reflects off the mirror at the same angle as the incident angle, resulting in a virtual image.
The part of leaf through which it is attached to the stem is ____________.- a)Petiole
- b)Lamina
- c)Vein
- d)Sepal
Correct answer is option 'A'. Can you explain this answer?
The part of leaf through which it is attached to the stem is ____________.
a)
Petiole
b)
Lamina
c)
Vein
d)
Sepal
|
Swara Chakraborty answered |
Understanding Leaf Structure
The leaf is a vital part of the plant that plays a crucial role in photosynthesis and overall growth. One important feature of leaf anatomy is how it connects to the stem.
What is a Petiole?
- The petiole is the stalk that attaches the leaf blade (lamina) to the stem of the plant.
- It serves as a supporting structure, allowing the leaf to be positioned for optimal sunlight absorption.
Functions of the Petiole
- Support: The petiole holds the leaf away from the stem, maximizing light exposure.
- Transport: It contains vascular tissues that transport water and nutrients from the stem to the leaf and vice versa.
Other Leaf Parts
- Lamina: This is the broad, flat part of the leaf where photosynthesis occurs.
- Vein: These are the vascular structures within the leaf that transport water and nutrients and provide structural support.
- Sepal: This is not a part of the leaf; it is a part of the flower that protects the developing bud.
Conclusion
In summary, the correct answer to the question is option 'A', petiole, as it is specifically the part of the leaf that connects it to the stem, enabling both support and nutrient transport. Understanding these components helps in grasping how plants function and thrive.
The leaf is a vital part of the plant that plays a crucial role in photosynthesis and overall growth. One important feature of leaf anatomy is how it connects to the stem.
What is a Petiole?
- The petiole is the stalk that attaches the leaf blade (lamina) to the stem of the plant.
- It serves as a supporting structure, allowing the leaf to be positioned for optimal sunlight absorption.
Functions of the Petiole
- Support: The petiole holds the leaf away from the stem, maximizing light exposure.
- Transport: It contains vascular tissues that transport water and nutrients from the stem to the leaf and vice versa.
Other Leaf Parts
- Lamina: This is the broad, flat part of the leaf where photosynthesis occurs.
- Vein: These are the vascular structures within the leaf that transport water and nutrients and provide structural support.
- Sepal: This is not a part of the leaf; it is a part of the flower that protects the developing bud.
Conclusion
In summary, the correct answer to the question is option 'A', petiole, as it is specifically the part of the leaf that connects it to the stem, enabling both support and nutrient transport. Understanding these components helps in grasping how plants function and thrive.
This set of elements produce strong magnets?- a)Steel and aluminum only
- b)Steel and nickle only
- c)Steel and pure iron only
- d)Pure iron, steel and an alloy of Al, Co, Ni and Fe
Correct answer is option 'D'. Can you explain this answer?
This set of elements produce strong magnets?
a)
Steel and aluminum only
b)
Steel and nickle only
c)
Steel and pure iron only
d)
Pure iron, steel and an alloy of Al, Co, Ni and Fe
|
Gayatri Chavan answered |
The correct answer is option "d".
Pure iron, steel, and an alloy of aluminum, cobalt, nickel, and iron (also known as "Alnico") are all materials that are known to produce strong magnets. Iron and steel are magnetic materials that are commonly used in the production of magnets, and the addition of cobalt, nickel, and aluminum to iron can further enhance its magnetic properties. These materials are often used in the production of permanent magnets, which are magnets that retain their magnetism over time.
The instrument used to see above the water surface from submarine is- a)Macroscope
- b)Periscope
- c)Microscope
- d)Telescope
Correct answer is option 'B'. Can you explain this answer?
The instrument used to see above the water surface from submarine is
a)
Macroscope
b)
Periscope
c)
Microscope
d)
Telescope
|
Rainbow Rise Classes answered |
The instrument used to see above the water surface from submarine is called periscope.
Mustard oil can be separated from water by- a)Centrifugation
- b)Elimination
- c)Decantation
- d)Sedimentation
Correct answer is option 'C'. Can you explain this answer?
Mustard oil can be separated from water by
a)
Centrifugation
b)
Elimination
c)
Decantation
d)
Sedimentation
|
|
Aman Choudhury answered |
Understanding the Separation of Mustard Oil from Water
When it comes to separating mustard oil from water, the most effective method is decantation. Let's delve into why this is the correct choice and how it works.
What is Decantation?
- Decantation is a process used to separate a liquid from solids or other liquids that do not mix.
- It involves pouring off the upper layer of liquid without disturbing the sediment or the lower layer.
Why Decantation Works for Mustard Oil and Water?
- Density Difference: Mustard oil is less dense than water. This means that when the two are mixed, the oil will float on top of the water.
- Layer Separation: After allowing the mixture to stand for a while, the oil will form a distinct layer above the water. This clear separation makes it easy to decant.
- Pouring Technique: By carefully pouring off the oil from the top layer into another container, you can effectively separate it from the water without mixing the two again.
Other Methods Explained
- Centrifugation: This method uses centrifugal force to separate components based on density. While effective, it is more complex and not necessary for simple mixtures like oil and water.
- Elimination: This term generally refers to removing something completely, and is not a separation technique.
- Sedimentation: This process allows solids to settle at the bottom. However, it is not suitable for separating two immiscible liquids like oil and water.
In conclusion, decantation is the simplest and most efficient method to separate mustard oil from water, thanks to the differences in their densities.
When it comes to separating mustard oil from water, the most effective method is decantation. Let's delve into why this is the correct choice and how it works.
What is Decantation?
- Decantation is a process used to separate a liquid from solids or other liquids that do not mix.
- It involves pouring off the upper layer of liquid without disturbing the sediment or the lower layer.
Why Decantation Works for Mustard Oil and Water?
- Density Difference: Mustard oil is less dense than water. This means that when the two are mixed, the oil will float on top of the water.
- Layer Separation: After allowing the mixture to stand for a while, the oil will form a distinct layer above the water. This clear separation makes it easy to decant.
- Pouring Technique: By carefully pouring off the oil from the top layer into another container, you can effectively separate it from the water without mixing the two again.
Other Methods Explained
- Centrifugation: This method uses centrifugal force to separate components based on density. While effective, it is more complex and not necessary for simple mixtures like oil and water.
- Elimination: This term generally refers to removing something completely, and is not a separation technique.
- Sedimentation: This process allows solids to settle at the bottom. However, it is not suitable for separating two immiscible liquids like oil and water.
In conclusion, decantation is the simplest and most efficient method to separate mustard oil from water, thanks to the differences in their densities.
The needle of the compass is made of a magnet because it .- a)Attracts metal
- b)Comes to rest in a north-south direction
- c)Gets deflected when a magnet is brought closer
- d)B and Cboth
Correct answer is option 'D'. Can you explain this answer?
The needle of the compass is made of a magnet because it .
a)
Attracts metal
b)
Comes to rest in a north-south direction
c)
Gets deflected when a magnet is brought closer
d)
B and Cboth
|
|
Varun Patel answered |
Introduction:
The needle of a compass is made of a magnet because it exhibits certain properties that make it ideal for use in a compass. The magnetized needle aligns itself with the Earth's magnetic field, allowing it to point in a north-south direction. Additionally, the needle also gets deflected when a magnet is brought closer, demonstrating its magnetic properties.
Attracts metal:
One of the properties of a magnet is its ability to attract certain types of metals, such as iron and steel. This attraction is due to the magnetic field produced by the magnet. When a metal object comes into contact with the magnet, it experiences a force of attraction and may be pulled towards it. The needle of a compass, being made of a magnet, also possesses this property. This is why the needle can attract metal objects, such as paperclips, when brought close to them.
Comes to rest in a north-south direction:
The Earth has its own magnetic field, with magnetic north and south poles. The needle of a compass is magnetized, which means it has its own north and south poles as well. When the compass is held horizontally, the needle aligns itself with the Earth's magnetic field. The north pole of the needle is attracted towards the Earth's magnetic south pole, while the south pole of the needle is attracted towards the Earth's magnetic north pole. As a result, the needle comes to rest in a north-south direction, allowing us to determine the cardinal directions.
Gets deflected when a magnet is brought closer:
When a magnet is brought near another magnet, it can exert a force on it. This force can cause the magnet to move or get deflected from its original position. In the case of a compass needle, which is also a magnet, it exhibits the same behavior. When a magnet is brought close to the compass needle, the needle can get deflected from its north-south alignment and point towards the nearby magnet instead. This deflection occurs due to the interaction between the magnetic fields of the two magnets.
Conclusion:
The needle of a compass is made of a magnet because it possesses certain properties that make it suitable for use in a compass. It can attract metal objects, comes to rest in a north-south direction aligning with the Earth's magnetic field, and gets deflected when a magnet is brought closer. These properties allow the compass needle to accurately indicate the cardinal directions and make it a reliable tool for navigation.
The needle of a compass is made of a magnet because it exhibits certain properties that make it ideal for use in a compass. The magnetized needle aligns itself with the Earth's magnetic field, allowing it to point in a north-south direction. Additionally, the needle also gets deflected when a magnet is brought closer, demonstrating its magnetic properties.
Attracts metal:
One of the properties of a magnet is its ability to attract certain types of metals, such as iron and steel. This attraction is due to the magnetic field produced by the magnet. When a metal object comes into contact with the magnet, it experiences a force of attraction and may be pulled towards it. The needle of a compass, being made of a magnet, also possesses this property. This is why the needle can attract metal objects, such as paperclips, when brought close to them.
Comes to rest in a north-south direction:
The Earth has its own magnetic field, with magnetic north and south poles. The needle of a compass is magnetized, which means it has its own north and south poles as well. When the compass is held horizontally, the needle aligns itself with the Earth's magnetic field. The north pole of the needle is attracted towards the Earth's magnetic south pole, while the south pole of the needle is attracted towards the Earth's magnetic north pole. As a result, the needle comes to rest in a north-south direction, allowing us to determine the cardinal directions.
Gets deflected when a magnet is brought closer:
When a magnet is brought near another magnet, it can exert a force on it. This force can cause the magnet to move or get deflected from its original position. In the case of a compass needle, which is also a magnet, it exhibits the same behavior. When a magnet is brought close to the compass needle, the needle can get deflected from its north-south alignment and point towards the nearby magnet instead. This deflection occurs due to the interaction between the magnetic fields of the two magnets.
Conclusion:
The needle of a compass is made of a magnet because it possesses certain properties that make it suitable for use in a compass. It can attract metal objects, comes to rest in a north-south direction aligning with the Earth's magnetic field, and gets deflected when a magnet is brought closer. These properties allow the compass needle to accurately indicate the cardinal directions and make it a reliable tool for navigation.
When HCl present in the stomach is secreted in a large quantity, it causes troubles. What is the remedy for this?- a)Use of NaOH
- b)Use of Milk of Magnesia
- c)Use of water
- d)Use of pepsin
Correct answer is option 'B'. Can you explain this answer?
When HCl present in the stomach is secreted in a large quantity, it causes troubles. What is the remedy for this?
a)
Use of NaOH
b)
Use of Milk of Magnesia
c)
Use of water
d)
Use of pepsin
|
Shivam Chakraborty answered |
Understanding Excess HCl in the Stomach
Excess secretion of hydrochloric acid (HCl) in the stomach can lead to discomfort and digestive issues such as acidity and heartburn.
Why Use Milk of Magnesia?
Milk of Magnesia is a common remedy for treating excess stomach acid. Here’s why it works:
- Neutralization: Milk of Magnesia contains magnesium hydroxide, which acts as a base. It neutralizes the excess HCl in the stomach, reducing acidity and alleviating discomfort.
- Relief from Symptoms: By neutralizing stomach acid, it helps in relieving symptoms like heartburn, indigestion, and upset stomach.
- Gentle Action: It is generally gentle on the stomach lining and provides effective relief without causing further irritation.
Other Options Explained
- a) Use of NaOH: Sodium hydroxide is a strong base and can be too harsh for the stomach, potentially causing burns or more severe discomfort.
- c) Use of Water: While drinking water can help dilute stomach acid temporarily, it does not neutralize it effectively.
- d) Use of Pepsin: Pepsin is an enzyme that aids in digestion and does not address the issue of excess acidity.
Conclusion
In summary, Milk of Magnesia is the preferred remedy for excess HCl in the stomach due to its ability to neutralize acid safely and effectively, providing quick relief from discomfort.
Excess secretion of hydrochloric acid (HCl) in the stomach can lead to discomfort and digestive issues such as acidity and heartburn.
Why Use Milk of Magnesia?
Milk of Magnesia is a common remedy for treating excess stomach acid. Here’s why it works:
- Neutralization: Milk of Magnesia contains magnesium hydroxide, which acts as a base. It neutralizes the excess HCl in the stomach, reducing acidity and alleviating discomfort.
- Relief from Symptoms: By neutralizing stomach acid, it helps in relieving symptoms like heartburn, indigestion, and upset stomach.
- Gentle Action: It is generally gentle on the stomach lining and provides effective relief without causing further irritation.
Other Options Explained
- a) Use of NaOH: Sodium hydroxide is a strong base and can be too harsh for the stomach, potentially causing burns or more severe discomfort.
- c) Use of Water: While drinking water can help dilute stomach acid temporarily, it does not neutralize it effectively.
- d) Use of Pepsin: Pepsin is an enzyme that aids in digestion and does not address the issue of excess acidity.
Conclusion
In summary, Milk of Magnesia is the preferred remedy for excess HCl in the stomach due to its ability to neutralize acid safely and effectively, providing quick relief from discomfort.
Piyush does not consume protein-rich food for a long time. Which of the following disorders can he face?- a)Poor vision
- b)Swelling of face
- c)Weak teeth
- d)
Bleeding gums
Correct answer is option 'B'. Can you explain this answer?
Piyush does not consume protein-rich food for a long time. Which of the following disorders can he face?
a)
Poor vision
b)
Swelling of face
c)
Weak teeth
d)
Bleeding gums
|
Gunjan Lakhani answered |
Deficiency of proteins in the diet for a long time results in swelling of the face, swollen neck, undergrowth of the body, etc. This is because proteins are the building blocks of the body and should be taken in sufficient amounts.
Which of the following devices is used to secure tall buildings from the effect of lightning?- a)Lightning rod
- b)Electroscope
- c)Voltmeter
- d)Seismograph
Correct answer is option 'A'. Can you explain this answer?
Which of the following devices is used to secure tall buildings from the effect of lightning?
a)
Lightning rod
b)
Electroscope
c)
Voltmeter
d)
Seismograph
|
|
Shivam Chakraborty answered |
Understanding Lightning Rods
Lightning rods are essential devices used to protect tall buildings from lightning strikes. Here’s how they work and why they are important:
What is a Lightning Rod?
- A lightning rod is a metal rod or conductor installed at the highest point of a structure.
- It is connected to the ground through a wire, allowing electrical charge to flow safely.
How Lightning Rods Work
- When lightning strikes, the rod provides a direct path for the electrical charge to travel to the ground.
- This prevents the lightning from passing through the building, which can cause fires, structural damage, or injury to occupants.
Benefits of Using Lightning Rods
- Protection: They significantly reduce the risk of lightning damage.
- Safety: They help ensure the safety of people inside the building by preventing electric shock.
- Cost-effective: Investing in a lightning rod can save on repair costs associated with lightning damage.
Conclusion
In summary, a lightning rod is a critical device for safeguarding tall buildings from the harmful effects of lightning strikes. Its ability to redirect electrical charges effectively protects both the structure and the people within it. Thus, the correct answer to the question is option 'A' - Lightning rod.
Lightning rods are essential devices used to protect tall buildings from lightning strikes. Here’s how they work and why they are important:
What is a Lightning Rod?
- A lightning rod is a metal rod or conductor installed at the highest point of a structure.
- It is connected to the ground through a wire, allowing electrical charge to flow safely.
How Lightning Rods Work
- When lightning strikes, the rod provides a direct path for the electrical charge to travel to the ground.
- This prevents the lightning from passing through the building, which can cause fires, structural damage, or injury to occupants.
Benefits of Using Lightning Rods
- Protection: They significantly reduce the risk of lightning damage.
- Safety: They help ensure the safety of people inside the building by preventing electric shock.
- Cost-effective: Investing in a lightning rod can save on repair costs associated with lightning damage.
Conclusion
In summary, a lightning rod is a critical device for safeguarding tall buildings from the harmful effects of lightning strikes. Its ability to redirect electrical charges effectively protects both the structure and the people within it. Thus, the correct answer to the question is option 'A' - Lightning rod.
Read the features of a plant as given below.
1. Roots are much shorter in size.
2. Stems are generally long and narrow.
3. Stems possess air spaces.
4. They have waxy upper surface.
Q. To which of these habitats does this plant belong?
- a)Desert
- b)Polar region
- c)Tropical region
- d)Aquatic
Correct answer is option 'D'. Can you explain this answer?
Read the features of a plant as given below.
1. Roots are much shorter in size.
2. Stems are generally long and narrow.
3. Stems possess air spaces.
4. They have waxy upper surface.
1. Roots are much shorter in size.
2. Stems are generally long and narrow.
3. Stems possess air spaces.
4. They have waxy upper surface.
Q. To which of these habitats does this plant belong?
a)
Desert
b)
Polar region
c)
Tropical region
d)
Aquatic
|
|
Bhumika Mamar answered |
Desert is the correct answer
At 8 a.m., the shadow of Ananya’s flat was as shown below.
Q. Which one of the following diagrams shows the shadow of her flat at 6.30 p.m.?
- a)
- b)
- c)
- d)None of these
Correct answer is option 'A'. Can you explain this answer?
At 8 a.m., the shadow of Ananya’s flat was as shown below.
Q. Which one of the following diagrams shows the shadow of her flat at 6.30 p.m.?
a)
b)
c)
d)
None of these
|
|
Naksh Manhas answered |
Because sun sets in west and the will be in East
A piece of clear glass and an object were placed between a lighted torch and a screen as shown in the diagram below.
A shadow was formed on the screen.Q. How could the shadow on the screen be enlarged?- a)By removing the clear glass
- b)By moving the object nearer to the screen
- c)By moving the object nearer to the clear glass
- d)By moving the torch further away from the clear glass
Correct answer is option 'C'. Can you explain this answer?
A piece of clear glass and an object were placed between a lighted torch and a screen as shown in the diagram below.
A shadow was formed on the screen.
Q. How could the shadow on the screen be enlarged?
a)
By removing the clear glass
b)
By moving the object nearer to the screen
c)
By moving the object nearer to the clear glass
d)
By moving the torch further away from the clear glass
|
Pushpa Pushpa answered |
A is the correct answer
In which of the following cases can evaporation be helpful?- a)Cooling water in an earthen pot
- b)Obtaining salt from sea water
- c)Obtaining powdered milk from milk
- d)All of these
Correct answer is option 'D'. Can you explain this answer?
In which of the following cases can evaporation be helpful?
a)
Cooling water in an earthen pot
b)
Obtaining salt from sea water
c)
Obtaining powdered milk from milk
d)
All of these
|
Maya Deshpande answered |
Evaporation is the process in which a liquid turns into a gas by gaining energy from its surroundings. It occurs when the molecules of a liquid gain enough energy to break free from the liquid's surface and enter the gas phase. Evaporation is a natural process that happens every day and has several practical applications. In the given options, evaporation can be helpful in all the cases:
a) Cooling water in an earthen pot:
- When water is stored in an earthen pot, the pot's porous walls allow water to slowly seep through and evaporate from the surface.
- As the water molecules gain energy from the surroundings and evaporate, they take away some heat, resulting in a cooling effect.
- This process of evaporation helps in keeping the water in the pot cool, making it suitable for drinking, especially in hot climates.
b) Obtaining salt from sea water:
- Evaporation is a crucial step in the process of obtaining salt from sea water.
- Sea water is collected in large shallow ponds or basins and left exposed to the sun and wind.
- As the water evaporates, it leaves behind the dissolved salt, which can then be harvested.
- This method is used in salt production industries around the world and is an effective way to obtain salt from sea water.
c) Obtaining powdered milk from milk:
- Evaporation is used in the production of powdered milk from regular milk.
- Milk is heated in large evaporators, which rapidly remove the water content from the milk.
- As the water evaporates, the remaining milk solids are left behind, which are then dried and powdered.
- This process helps in extending the shelf life of milk and makes it more convenient for storage and transportation.
d) All of these:
- Each of the given cases demonstrates the practical applications of evaporation and how it can be helpful in various situations.
- Whether it is cooling water in an earthen pot, obtaining salt from sea water, or producing powdered milk, evaporation plays a significant role in achieving the desired results.
In conclusion, evaporation can be beneficial in all the given cases. It helps in cooling water, obtaining salt from sea water, and producing powdered milk. Understanding the process of evaporation and its applications allows us to utilize its benefits in various aspects of our daily lives.
a) Cooling water in an earthen pot:
- When water is stored in an earthen pot, the pot's porous walls allow water to slowly seep through and evaporate from the surface.
- As the water molecules gain energy from the surroundings and evaporate, they take away some heat, resulting in a cooling effect.
- This process of evaporation helps in keeping the water in the pot cool, making it suitable for drinking, especially in hot climates.
b) Obtaining salt from sea water:
- Evaporation is a crucial step in the process of obtaining salt from sea water.
- Sea water is collected in large shallow ponds or basins and left exposed to the sun and wind.
- As the water evaporates, it leaves behind the dissolved salt, which can then be harvested.
- This method is used in salt production industries around the world and is an effective way to obtain salt from sea water.
c) Obtaining powdered milk from milk:
- Evaporation is used in the production of powdered milk from regular milk.
- Milk is heated in large evaporators, which rapidly remove the water content from the milk.
- As the water evaporates, the remaining milk solids are left behind, which are then dried and powdered.
- This process helps in extending the shelf life of milk and makes it more convenient for storage and transportation.
d) All of these:
- Each of the given cases demonstrates the practical applications of evaporation and how it can be helpful in various situations.
- Whether it is cooling water in an earthen pot, obtaining salt from sea water, or producing powdered milk, evaporation plays a significant role in achieving the desired results.
In conclusion, evaporation can be beneficial in all the given cases. It helps in cooling water, obtaining salt from sea water, and producing powdered milk. Understanding the process of evaporation and its applications allows us to utilize its benefits in various aspects of our daily lives.
Shelly is drinking orange juice and finds it sour. Which acid makes the orange juice taste sour?- a)Citric acid
- b)Acetic acid
- c)Formic acid
- d)Hydrochloric acid
Correct answer is option 'A'. Can you explain this answer?
Shelly is drinking orange juice and finds it sour. Which acid makes the orange juice taste sour?
a)
Citric acid
b)
Acetic acid
c)
Formic acid
d)
Hydrochloric acid
|
|
Rainbow Rise Classes answered |
Citric acid is responsible for the sour taste of orange juice.
Which of the following substances is not soluble in water?- a)Copper sulphate
- b)Potassium permanganate
- c)Sugar
- d)All are soluble.
Correct answer is option 'D'. Can you explain this answer?
Which of the following substances is not soluble in water?
a)
Copper sulphate
b)
Potassium permanganate
c)
Sugar
d)
All are soluble.
|
|
Rohini Seth answered |
All of the given substances are soluble in water and are called solute. Solute is the substance which is dissolved in a solvent.
When the temperature of the solid is increased, the energy of the particles increases.- a)Heat
- b)Potential
- c)Kinetic
- d)Chemical
Correct answer is option 'C'. Can you explain this answer?
When the temperature of the solid is increased, the energy of the particles increases.
a)
Heat
b)
Potential
c)
Kinetic
d)
Chemical
|
|
Gayatri Chavan answered |
When the temperature of a solid is increased, the energy of its particles increases. This increase in energy is due to an increase in the kinetic energy of the particles. The kinetic energy of a particle is the energy it possesses due to its motion. When the temperature of a solid increases, the particles gain more kinetic energy and move faster.
Therefore, the correct answer is "Kinetic." Heat and potential energy are not directly related to the motion of particles in a solid. Chemical energy is the energy stored in the bonds between atoms or molecules, and it is not affected by changes in temperature.
What is the name of the process by which pure solids of copper sulphate can be obtained?- a)Crystallisation
- b)Filtration
- c)Sublimation
- d)Fraction distillation
Correct answer is option 'A'. Can you explain this answer?
What is the name of the process by which pure solids of copper sulphate can be obtained?
a)
Crystallisation
b)
Filtration
c)
Sublimation
d)
Fraction distillation
|
Tanishq Mehra answered |
The process to obtain pure solids of copper sulphate is called crystallisation.
Crystallisation is a process in which a solid substance is dissolved in a solvent to form a solution, and then the solvent is slowly evaporated or cooled down to allow the formation of pure solid crystals. This method is commonly used to purify solids and separate them from impurities.
The steps involved in the process of crystallisation are:
1. Dissolving the solid: The first step in the process is to dissolve the solid substance, in this case, copper sulphate, in a suitable solvent. The solvent used should be able to dissolve the solid at a high temperature but have a low solubility at a lower temperature. In the case of copper sulphate, water is commonly used as the solvent.
2. Heating and stirring: The mixture of the solid and solvent is heated and stirred to ensure that the solid completely dissolves in the solvent. The heating helps to increase the solubility of the solid in the solvent.
3. Filtering: After the solid is completely dissolved, the solution is filtered to remove any insoluble impurities that may be present. This step helps to obtain a clear solution.
4. Cooling or evaporation: The filtered solution is then allowed to cool down slowly or evaporate slowly. As the temperature decreases, the solubility of the solid decreases, and the solid particles start to come together to form crystals. The crystals grow over time and can be observed as the solution becomes more concentrated.
5. Separating the crystals: Once a sufficient amount of crystals has formed, they can be separated from the remaining solution. This can be done by carefully pouring off the solution or using a filter paper to collect the crystals.
6. Drying the crystals: The separated crystals are then dried to remove any remaining moisture. This can be done by placing the crystals on a filter paper or in an oven at a low temperature.
By following these steps, pure solids of copper sulphate can be obtained through the process of crystallisation. The crystals obtained are usually more pure compared to the original solid, as impurities are left behind in the solution during the filtration and crystallisation process.
Crystallisation is a process in which a solid substance is dissolved in a solvent to form a solution, and then the solvent is slowly evaporated or cooled down to allow the formation of pure solid crystals. This method is commonly used to purify solids and separate them from impurities.
The steps involved in the process of crystallisation are:
1. Dissolving the solid: The first step in the process is to dissolve the solid substance, in this case, copper sulphate, in a suitable solvent. The solvent used should be able to dissolve the solid at a high temperature but have a low solubility at a lower temperature. In the case of copper sulphate, water is commonly used as the solvent.
2. Heating and stirring: The mixture of the solid and solvent is heated and stirred to ensure that the solid completely dissolves in the solvent. The heating helps to increase the solubility of the solid in the solvent.
3. Filtering: After the solid is completely dissolved, the solution is filtered to remove any insoluble impurities that may be present. This step helps to obtain a clear solution.
4. Cooling or evaporation: The filtered solution is then allowed to cool down slowly or evaporate slowly. As the temperature decreases, the solubility of the solid decreases, and the solid particles start to come together to form crystals. The crystals grow over time and can be observed as the solution becomes more concentrated.
5. Separating the crystals: Once a sufficient amount of crystals has formed, they can be separated from the remaining solution. This can be done by carefully pouring off the solution or using a filter paper to collect the crystals.
6. Drying the crystals: The separated crystals are then dried to remove any remaining moisture. This can be done by placing the crystals on a filter paper or in an oven at a low temperature.
By following these steps, pure solids of copper sulphate can be obtained through the process of crystallisation. The crystals obtained are usually more pure compared to the original solid, as impurities are left behind in the solution during the filtration and crystallisation process.
Pulling out seed from cotton is called- a)Sieving
- b)Ginning
- c)Filtering
- d)Looming
Correct answer is option 'B'. Can you explain this answer?
Pulling out seed from cotton is called
a)
Sieving
b)
Ginning
c)
Filtering
d)
Looming
|
|
Muskaan Joshi answered |
Introduction:
Pulling out seeds from cotton is an important process in the production of cotton fibers. This process is known as ginning.
Explanation:
Ginning is the process of separating the seeds from the cotton fibers. It is done using a machine called a cotton gin. The cotton gin is designed to remove the seeds from the cotton fibers efficiently and quickly.
Process of Ginning:
The ginning process involves the following steps:
1. Harvesting: Cotton is typically harvested when the bolls (the protective capsules that enclose the cotton fibers) are fully mature. The bolls are picked by hand or by using mechanical harvesters.
2. Module Building: After harvesting, the cotton is collected and formed into large modules, which are compact stacks of cotton bales. These modules are transported to the ginning facility.
3. Feeding: At the ginning facility, the modules are opened, and the cotton is fed into the cotton gin. The cotton gin consists of a series of rotating saws and brushes that separate the fibers from the seeds.
4. Separation: The rotating saws in the gin pull the cotton fibers away from the seeds. The seeds are too large to pass through the small openings in the gin, so they are separated from the fibers.
5. Cleaning: Once the seeds are separated, they are cleaned to remove any remaining fibers or debris. This is done using various cleaning mechanisms such as air suction or vibrating screens.
6. Collection: The cleaned seeds are collected and either used for planting new cotton crops or processed further to extract cottonseed oil.
7. Fiber Processing: After the seeds are removed, the cotton fibers are further processed to remove impurities and make them ready for spinning into yarn or fabric.
Conclusion:
Ginning is the process of pulling out seeds from cotton. It plays a crucial role in cotton production as it separates the fibers from the seeds, making the cotton ready for further processing. The cotton gin efficiently and effectively performs this task, ensuring that the seeds are separated without damaging the fibers.
Pulling out seeds from cotton is an important process in the production of cotton fibers. This process is known as ginning.
Explanation:
Ginning is the process of separating the seeds from the cotton fibers. It is done using a machine called a cotton gin. The cotton gin is designed to remove the seeds from the cotton fibers efficiently and quickly.
Process of Ginning:
The ginning process involves the following steps:
1. Harvesting: Cotton is typically harvested when the bolls (the protective capsules that enclose the cotton fibers) are fully mature. The bolls are picked by hand or by using mechanical harvesters.
2. Module Building: After harvesting, the cotton is collected and formed into large modules, which are compact stacks of cotton bales. These modules are transported to the ginning facility.
3. Feeding: At the ginning facility, the modules are opened, and the cotton is fed into the cotton gin. The cotton gin consists of a series of rotating saws and brushes that separate the fibers from the seeds.
4. Separation: The rotating saws in the gin pull the cotton fibers away from the seeds. The seeds are too large to pass through the small openings in the gin, so they are separated from the fibers.
5. Cleaning: Once the seeds are separated, they are cleaned to remove any remaining fibers or debris. This is done using various cleaning mechanisms such as air suction or vibrating screens.
6. Collection: The cleaned seeds are collected and either used for planting new cotton crops or processed further to extract cottonseed oil.
7. Fiber Processing: After the seeds are removed, the cotton fibers are further processed to remove impurities and make them ready for spinning into yarn or fabric.
Conclusion:
Ginning is the process of pulling out seeds from cotton. It plays a crucial role in cotton production as it separates the fibers from the seeds, making the cotton ready for further processing. The cotton gin efficiently and effectively performs this task, ensuring that the seeds are separated without damaging the fibers.
In which of the following cases will regular reflection not take place when a beam of light strikes it?- a)Marble flooring with oil spread over
- b)Mirror
- c)Shiny metal sheet
- d)Unpolished wooden surface
Correct answer is option 'C'. Can you explain this answer?
In which of the following cases will regular reflection not take place when a beam of light strikes it?
a)
Marble flooring with oil spread over
b)
Mirror
c)
Shiny metal sheet
d)
Unpolished wooden surface
|
Ananya Das answered |
Regular Reflection
Regular reflection is the phenomenon where light waves strike a smooth surface and bounce back in a predictable, straight-line manner. This occurs when the surface is highly polished or smooth, allowing the light waves to reflect at the same angle as they strike the surface.
Explanation of Options
a) Marble flooring with oil spread over: In this case, regular reflection will still take place because the oil spread over the marble flooring does not affect the smoothness of the surface. The light waves will still reflect in a predictable manner.
b) Mirror: Mirrors are specifically designed to have a highly polished and smooth surface. This ensures that regular reflection occurs when light waves strike them. Therefore, regular reflection will take place when a beam of light strikes a mirror.
c) Shiny metal sheet: The correct answer is option 'C'. Regular reflection will not take place when a beam of light strikes a shiny metal sheet. Shiny metal surfaces have a highly polished and smooth surface, similar to mirrors. However, unlike mirrors, metals also have the ability to absorb and scatter light. This leads to irregular reflection, where the light waves bounce off in different directions rather than following the law of reflection.
d) Unpolished wooden surface: In the case of an unpolished wooden surface, regular reflection will not take place. Wood is not a smooth surface, and its texture and roughness cause the light waves to scatter in various directions upon striking it.
Conclusion
Regular reflection occurs when light waves strike a smooth surface such as a mirror or a polished surface. Shiny metal sheets do have a smooth surface, but the ability of metals to absorb and scatter light leads to irregular reflection. Unpolished surfaces like wood do not have a smooth surface, causing the light waves to scatter in different directions.
Regular reflection is the phenomenon where light waves strike a smooth surface and bounce back in a predictable, straight-line manner. This occurs when the surface is highly polished or smooth, allowing the light waves to reflect at the same angle as they strike the surface.
Explanation of Options
a) Marble flooring with oil spread over: In this case, regular reflection will still take place because the oil spread over the marble flooring does not affect the smoothness of the surface. The light waves will still reflect in a predictable manner.
b) Mirror: Mirrors are specifically designed to have a highly polished and smooth surface. This ensures that regular reflection occurs when light waves strike them. Therefore, regular reflection will take place when a beam of light strikes a mirror.
c) Shiny metal sheet: The correct answer is option 'C'. Regular reflection will not take place when a beam of light strikes a shiny metal sheet. Shiny metal surfaces have a highly polished and smooth surface, similar to mirrors. However, unlike mirrors, metals also have the ability to absorb and scatter light. This leads to irregular reflection, where the light waves bounce off in different directions rather than following the law of reflection.
d) Unpolished wooden surface: In the case of an unpolished wooden surface, regular reflection will not take place. Wood is not a smooth surface, and its texture and roughness cause the light waves to scatter in various directions upon striking it.
Conclusion
Regular reflection occurs when light waves strike a smooth surface such as a mirror or a polished surface. Shiny metal sheets do have a smooth surface, but the ability of metals to absorb and scatter light leads to irregular reflection. Unpolished surfaces like wood do not have a smooth surface, causing the light waves to scatter in different directions.
When a piece of iron metal is placed in copper sulphate solution, which of the following is not observed?- a)Iron displaces copper from the sulphate solution.
- b)There is no change in colour of the solution.
- c)Iron acquires reddish-brown colour.
- d)All of the above
Correct answer is option 'B'. Can you explain this answer?
When a piece of iron metal is placed in copper sulphate solution, which of the following is not observed?
a)
Iron displaces copper from the sulphate solution.
b)
There is no change in colour of the solution.
c)
Iron acquires reddish-brown colour.
d)
All of the above
|
|
Aaditya Chawla answered |
Reaction Between Iron and Copper Sulphate
When iron metal is placed in a copper sulphate solution, a chemical reaction occurs. Here’s what happens:
Displacement Reaction
- Iron (Fe) is more reactive than copper (Cu).
- In this displacement reaction, iron displaces copper from the copper sulphate solution (CuSO4).
Observation of Changes
- Change in Colour of the Solution: The blue colour of the copper sulphate solution changes to a light green as copper is displaced by iron.
- Formation of Copper Deposits: Reddish-brown copper metal is deposited on the surface of the iron.
Analysis of Options
Now, let’s analyze the options given in the question:
- Option A: Iron displaces copper from the sulphate solution.
- This is true; copper is displaced, confirming the reaction.
- Option B: There is no change in the colour of the solution.
- This is false; the blue colour changes to green, indicating a change.
- Option C: Iron acquires reddish-brown colour.
- This is true; the iron gets covered with reddish-brown copper.
- Option D: All of the above.
- This cannot be correct since option B is false.
Conclusion
The correct answer is option 'B' because there is indeed a noticeable change in the colour of the solution when iron is placed in copper sulphate, contradicting the statement that there is no change.
When iron metal is placed in a copper sulphate solution, a chemical reaction occurs. Here’s what happens:
Displacement Reaction
- Iron (Fe) is more reactive than copper (Cu).
- In this displacement reaction, iron displaces copper from the copper sulphate solution (CuSO4).
Observation of Changes
- Change in Colour of the Solution: The blue colour of the copper sulphate solution changes to a light green as copper is displaced by iron.
- Formation of Copper Deposits: Reddish-brown copper metal is deposited on the surface of the iron.
Analysis of Options
Now, let’s analyze the options given in the question:
- Option A: Iron displaces copper from the sulphate solution.
- This is true; copper is displaced, confirming the reaction.
- Option B: There is no change in the colour of the solution.
- This is false; the blue colour changes to green, indicating a change.
- Option C: Iron acquires reddish-brown colour.
- This is true; the iron gets covered with reddish-brown copper.
- Option D: All of the above.
- This cannot be correct since option B is false.
Conclusion
The correct answer is option 'B' because there is indeed a noticeable change in the colour of the solution when iron is placed in copper sulphate, contradicting the statement that there is no change.
Which of the following is incorrect regarding skeletal support system of different organisms?- a)Earthworms have liquid skeleton where liquid filled spaces inside the body serve as a support system
- b)Skeletal muscles work in pairs
- c)Snakes have bristles on the under surface of the body to support movement.
- d)Birds have hollow bones with air filled cavities.
Correct answer is option 'C'. Can you explain this answer?
Which of the following is incorrect regarding skeletal support system of different organisms?
a)
Earthworms have liquid skeleton where liquid filled spaces inside the body serve as a support system
b)
Skeletal muscles work in pairs
c)
Snakes have bristles on the under surface of the body to support movement.
d)
Birds have hollow bones with air filled cavities.
|
Preethi Dasgupta answered |
Understanding Skeletal Support Systems
The skeletal support system varies significantly among different organisms, and option 'C' is incorrect regarding the features of snakes. Here’s an explanation of why this statement is inaccurate:
Earthworms' Liquid Skeleton
- Earthworms utilize a hydrostatic skeleton, where fluid-filled coelomic spaces provide support.
- This structure helps maintain body shape and enables movement through contraction of muscles against the liquid.
Skeletal Muscles Work in Pairs
- Muscles always function in antagonistic pairs; when one muscle contracts, the other relaxes.
- This mechanism is crucial for coordinated movement across various organisms, including humans.
Snakes and Their Movement
- The incorrect statement suggests that snakes have bristles on the undersurface for support, but this is not true.
- Snakes do not possess bristles. Instead, they rely on their flexible spine and scales for locomotion.
- Their movement involves slithering using muscle contractions and friction against the ground.
Birds' Hollow Bones
- Birds have evolved hollow bones with air-filled cavities, making them lighter for flight.
- This adaptation is essential for reducing body weight without sacrificing strength.
Conclusion
In summary, option 'C' is incorrect because snakes do not use bristles for movement; they depend on their unique anatomy and muscle coordination. Understanding these differences in skeletal systems helps appreciate how each organism adapts to its environment.
The skeletal support system varies significantly among different organisms, and option 'C' is incorrect regarding the features of snakes. Here’s an explanation of why this statement is inaccurate:
Earthworms' Liquid Skeleton
- Earthworms utilize a hydrostatic skeleton, where fluid-filled coelomic spaces provide support.
- This structure helps maintain body shape and enables movement through contraction of muscles against the liquid.
Skeletal Muscles Work in Pairs
- Muscles always function in antagonistic pairs; when one muscle contracts, the other relaxes.
- This mechanism is crucial for coordinated movement across various organisms, including humans.
Snakes and Their Movement
- The incorrect statement suggests that snakes have bristles on the undersurface for support, but this is not true.
- Snakes do not possess bristles. Instead, they rely on their flexible spine and scales for locomotion.
- Their movement involves slithering using muscle contractions and friction against the ground.
Birds' Hollow Bones
- Birds have evolved hollow bones with air-filled cavities, making them lighter for flight.
- This adaptation is essential for reducing body weight without sacrificing strength.
Conclusion
In summary, option 'C' is incorrect because snakes do not use bristles for movement; they depend on their unique anatomy and muscle coordination. Understanding these differences in skeletal systems helps appreciate how each organism adapts to its environment.
Find the odd one out in the given series.43, 88, 179, 358- a)43
- b)88
- c)179
- d)358
Correct answer is option 'C'. Can you explain this answer?
Find the odd one out in the given series.
43, 88, 179, 358
a)
43
b)
88
c)
179
d)
358
|
|
Nilotpal Nambiar answered |
Odd One Out: 43, 88, 179, 358
Explanation:
To find the odd one out in the given series, we need to analyze the pattern and identify the number that does not fit.
Pattern Analysis:
Let's examine the given series: 43, 88, 179, 358.
- The first number, 43, is multiplied by 2 and then 2 is added to it to get the second number, 88. (43 * 2 + 2 = 88)
- The second number, 88, is multiplied by 2 and then 3 is added to it to get the third number, 179. (88 * 2 + 3 = 179)
- The third number, 179, is multiplied by 2 and then 4 is added to it to get the fourth number, 358. (179 * 2 + 4 = 358)
Pattern Conclusion:
From the pattern analysis, we can observe that each number in the series is obtained by multiplying the previous number by 2 and then adding a specific number to it.
Identifying the Odd One Out:
Now, let's apply the same pattern to the given options: 43, 88, 179, and 358.
- Option A: 43 * 2 + 2 = 88
- Option B: 88 * 2 + 3 = 179
- Option C: 179 * 2 + 4 = 362
- Option D: 358 * 2 + 5 = 721
Comparing the results with the given options, we can see that the third number in the series, 179, does not match with the calculated value of 362. Therefore, option C (179) is the odd one out in the given series.
Conclusion:
The odd one out in the given series is option C (179) because it does not follow the pattern observed in the series.
Explanation:
To find the odd one out in the given series, we need to analyze the pattern and identify the number that does not fit.
Pattern Analysis:
Let's examine the given series: 43, 88, 179, 358.
- The first number, 43, is multiplied by 2 and then 2 is added to it to get the second number, 88. (43 * 2 + 2 = 88)
- The second number, 88, is multiplied by 2 and then 3 is added to it to get the third number, 179. (88 * 2 + 3 = 179)
- The third number, 179, is multiplied by 2 and then 4 is added to it to get the fourth number, 358. (179 * 2 + 4 = 358)
Pattern Conclusion:
From the pattern analysis, we can observe that each number in the series is obtained by multiplying the previous number by 2 and then adding a specific number to it.
Identifying the Odd One Out:
Now, let's apply the same pattern to the given options: 43, 88, 179, and 358.
- Option A: 43 * 2 + 2 = 88
- Option B: 88 * 2 + 3 = 179
- Option C: 179 * 2 + 4 = 362
- Option D: 358 * 2 + 5 = 721
Comparing the results with the given options, we can see that the third number in the series, 179, does not match with the calculated value of 362. Therefore, option C (179) is the odd one out in the given series.
Conclusion:
The odd one out in the given series is option C (179) because it does not follow the pattern observed in the series.
If LINGER is coded as !@#$%& and ANGER is coded as *#$%&, then how will you code GINGER ?- a)$@#$%&
- b)!@#$%&
- c)!@#$%
- d)$#$%&
Correct answer is option 'A'. Can you explain this answer?
If LINGER is coded as !@#$%& and ANGER is coded as *#$%&, then how will you code GINGER ?
a)
$@#$%&
b)
!@#$%&
c)
!@#$%
d)
$#$%&
|
Eduskill Classes answered |
The code of different letters is given below as:
L -- !
I -- @
N --- #
G --- $
E --- %
R ----- &
Similarly, we can find out the code for GINGER.
GINGER = $@#$%&
L -- !
I -- @
N --- #
G --- $
E --- %
R ----- &
Similarly, we can find out the code for GINGER.
GINGER = $@#$%&
Mary made the following statements about photosynthesis.Which of the statements is/are INCORRECT?- a)Oxygen production takes place during photosynthesis
- b)Only heat energy is needed for plants to carry out photosynthesis
- c)Photosynthesis can only take place in cells that contain chloroplasts
- d)During respiration, the excess food made during photosynthesis is used up for energy
Correct answer is option 'B'. Can you explain this answer?
Mary made the following statements about photosynthesis.Which of the statements is/are INCORRECT?
a)
Oxygen production takes place during photosynthesis
b)
Only heat energy is needed for plants to carry out photosynthesis
c)
Photosynthesis can only take place in cells that contain chloroplasts
d)
During respiration, the excess food made during photosynthesis is used up for energy
|
Manasing Pawar answered |
Only heat energy is needed for plants to carry out photosynthesis
Which of the following statements should be followed while using a symbol for a unit of a physical quantity?- a)They can be written in full
- b)The symbol named after scientist should have capital letter
- c)They take plural forms
- d)They should always be written in lowercase
Correct answer is option 'B'. Can you explain this answer?
Which of the following statements should be followed while using a symbol for a unit of a physical quantity?
a)
They can be written in full
b)
The symbol named after scientist should have capital letter
c)
They take plural forms
d)
They should always be written in lowercase
|
|
Abhishek Phogat answered |
E.g ~ N/m^2 and Hz.... Both Newton and Hertz are scientists.. Hence written in capitals...
In which of the following a permanent magnet not used?- a)Loudspeakers
- b)In magnetic door catches
- c)In compasses
- d)None of these
Correct answer is option 'D'. Can you explain this answer?
In which of the following a permanent magnet not used?
a)
Loudspeakers
b)
In magnetic door catches
c)
In compasses
d)
None of these
|
Parth Das answered |
Permanent Magnet
A permanent magnet is a material that produces a magnetic field and retains its magnetism over a long period of time. It is made from materials such as iron, nickel, and cobalt, which have strong magnetic properties.
Loudspeakers
In loudspeakers, a permanent magnet is used. The magnet is typically made of a material called neodymium, which is a type of rare earth magnet. The magnet is placed behind the speaker cone and interacts with an electromagnet to produce sound waves.
Magnetic Door Catches
In magnetic door catches, a permanent magnet is used. The magnet is often embedded in the door frame, while a metal plate is attached to the door. When the door is closed, the magnet attracts the metal plate, holding the door securely in place.
Compasses
In compasses, a permanent magnet is used. The magnet is typically a small, lightweight magnetized needle that is free to rotate. The needle aligns itself with the Earth's magnetic field, allowing the user to determine the direction of North.
None of these
None of these options is correct because all of them use permanent magnets. Loudspeakers use magnets to produce sound, magnetic door catches use magnets to hold doors in place, and compasses use magnets to determine direction. Therefore, the correct answer is option 'D', none of these.
A permanent magnet is a material that produces a magnetic field and retains its magnetism over a long period of time. It is made from materials such as iron, nickel, and cobalt, which have strong magnetic properties.
Loudspeakers
In loudspeakers, a permanent magnet is used. The magnet is typically made of a material called neodymium, which is a type of rare earth magnet. The magnet is placed behind the speaker cone and interacts with an electromagnet to produce sound waves.
Magnetic Door Catches
In magnetic door catches, a permanent magnet is used. The magnet is often embedded in the door frame, while a metal plate is attached to the door. When the door is closed, the magnet attracts the metal plate, holding the door securely in place.
Compasses
In compasses, a permanent magnet is used. The magnet is typically a small, lightweight magnetized needle that is free to rotate. The needle aligns itself with the Earth's magnetic field, allowing the user to determine the direction of North.
None of these
None of these options is correct because all of them use permanent magnets. Loudspeakers use magnets to produce sound, magnetic door catches use magnets to hold doors in place, and compasses use magnets to determine direction. Therefore, the correct answer is option 'D', none of these.
A solid, transparent sphere has a small, opaque center. When observed from outside, the apparent position of the dot will be:- a)Farther away from the eye than its actual position
- b)Closer to the eye than its actual position
- c)The same as its actual position
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
A solid, transparent sphere has a small, opaque center. When observed from outside, the apparent position of the dot will be:
a)
Farther away from the eye than its actual position
b)
Closer to the eye than its actual position
c)
The same as its actual position
d)
None of these
|
|
Meena Yadav answered |
The correct option is 'C'
The same as its actual position.
The same as its actual position.
Cooking of rice is an example of:- a)Reversible change
- b)Irreversible change
- c)Irreversible and endothermic change
- d)Reversible and endothermic change
Correct answer is option 'C'. Can you explain this answer?
Cooking of rice is an example of:
a)
Reversible change
b)
Irreversible change
c)
Irreversible and endothermic change
d)
Reversible and endothermic change
|
|
Anirban Saini answered |
Introduction
The cooking of rice is an example of an irreversible and endothermic change. When rice is cooked, it undergoes a chemical reaction that results in irreversible changes to its physical and chemical properties. Additionally, the process of cooking rice requires the absorption of heat energy from an external source, making it an endothermic change.
Irreversible Change
1. Definition: An irreversible change refers to a change that cannot be reversed or undone. It involves the formation of new substances with different properties.
2. Explanation: When rice is cooked, it absorbs water and undergoes a chemical reaction that alters its composition. The starch present in the rice grains absorbs water, swells up, and becomes gelatinized. This irreversible change results in a softer texture and different taste compared to uncooked rice.
3. Example: Other examples of irreversible changes include burning wood, rusting of iron, and baking a cake. In each of these cases, the original substances are transformed into new substances that cannot be easily reversed.
Endothermic Change
1. Definition: An endothermic change is a process that absorbs heat energy from the surroundings.
2. Explanation: Cooking rice requires the application of heat energy to the rice and water mixture. This heat energy is absorbed by the rice grains, causing them to heat up and undergo the cooking process. The absorption of heat is necessary to break down the starch molecules and allow them to absorb water, resulting in the softening and cooking of the rice.
3. Example: Other examples of endothermic changes include melting ice, evaporating water, and photosynthesis. These processes all require the input of heat energy to proceed.
Conclusion
The cooking of rice is an example of an irreversible and endothermic change. The process involves the irreversible transformation of rice grains through the absorption of heat energy. Understanding these concepts helps us appreciate the chemical and physical changes that occur during cooking and the role of energy transfer in these processes.
The cooking of rice is an example of an irreversible and endothermic change. When rice is cooked, it undergoes a chemical reaction that results in irreversible changes to its physical and chemical properties. Additionally, the process of cooking rice requires the absorption of heat energy from an external source, making it an endothermic change.
Irreversible Change
1. Definition: An irreversible change refers to a change that cannot be reversed or undone. It involves the formation of new substances with different properties.
2. Explanation: When rice is cooked, it absorbs water and undergoes a chemical reaction that alters its composition. The starch present in the rice grains absorbs water, swells up, and becomes gelatinized. This irreversible change results in a softer texture and different taste compared to uncooked rice.
3. Example: Other examples of irreversible changes include burning wood, rusting of iron, and baking a cake. In each of these cases, the original substances are transformed into new substances that cannot be easily reversed.
Endothermic Change
1. Definition: An endothermic change is a process that absorbs heat energy from the surroundings.
2. Explanation: Cooking rice requires the application of heat energy to the rice and water mixture. This heat energy is absorbed by the rice grains, causing them to heat up and undergo the cooking process. The absorption of heat is necessary to break down the starch molecules and allow them to absorb water, resulting in the softening and cooking of the rice.
3. Example: Other examples of endothermic changes include melting ice, evaporating water, and photosynthesis. These processes all require the input of heat energy to proceed.
Conclusion
The cooking of rice is an example of an irreversible and endothermic change. The process involves the irreversible transformation of rice grains through the absorption of heat energy. Understanding these concepts helps us appreciate the chemical and physical changes that occur during cooking and the role of energy transfer in these processes.
Which of the following condition(s) is/are essential for rusting to occur ?(a) Heat
(b) Moisture
(c) Carbon dioxide
(d) Oxygen- a)Only (b)
- b)Both (b) and (d)
- c)Only (d)
- d)Both (a) and (b)
Correct answer is option 'B'. Can you explain this answer?
Which of the following condition(s) is/are essential for rusting to occur ?
(a) Heat
(b) Moisture
(c) Carbon dioxide
(d) Oxygen
(b) Moisture
(c) Carbon dioxide
(d) Oxygen
a)
Only (b)
b)
Both (b) and (d)
c)
Only (d)
d)
Both (a) and (b)
|
|
Prasad Kulkarni answered |
Understanding Rusting
Rusting is a chemical process that occurs when iron or its alloys corrode in the presence of moisture and oxygen. To understand why option 'B' (Both (b) and (d)) is correct, let's break down the essential conditions for rusting.
Essential Conditions for Rusting
- Moisture (Water)
- Rusting requires water to initiate the reaction.
- Water acts as an electrolyte, facilitating the transfer of electrons, which is crucial for the oxidation of iron.
- Oxygen
- Oxygen in the air reacts with iron in the presence of water.
- This reaction forms iron oxide, commonly known as rust.
Other Options Explained
- Heat
- While heat can accelerate corrosion, it is not a necessary condition for rusting to occur.
- Carbon Dioxide
- Carbon dioxide is not essential for rusting. Although it can play a role in some corrosion processes, it is not a primary factor in the rusting of iron.
Conclusion
In summary, the two critical elements that must be present for rusting to occur are moisture and oxygen. Thus, the correct answer is option 'B' (Both (b) and (d)).
Rusting is a chemical process that occurs when iron or its alloys corrode in the presence of moisture and oxygen. To understand why option 'B' (Both (b) and (d)) is correct, let's break down the essential conditions for rusting.
Essential Conditions for Rusting
- Moisture (Water)
- Rusting requires water to initiate the reaction.
- Water acts as an electrolyte, facilitating the transfer of electrons, which is crucial for the oxidation of iron.
- Oxygen
- Oxygen in the air reacts with iron in the presence of water.
- This reaction forms iron oxide, commonly known as rust.
Other Options Explained
- Heat
- While heat can accelerate corrosion, it is not a necessary condition for rusting to occur.
- Carbon Dioxide
- Carbon dioxide is not essential for rusting. Although it can play a role in some corrosion processes, it is not a primary factor in the rusting of iron.
Conclusion
In summary, the two critical elements that must be present for rusting to occur are moisture and oxygen. Thus, the correct answer is option 'B' (Both (b) and (d)).
Sameer’s torch does not light up. This could be because of the following reason:- a)There is a gap between the batteries
- b)The metal tip of the bulb is not connected to one of the batteries
- c)The positive terminal of one battery is not connected to the negative terminal of the next battery
- d)All are correct
Correct answer is option 'D'. Can you explain this answer?
Sameer’s torch does not light up. This could be because of the following reason:
a)
There is a gap between the batteries
b)
The metal tip of the bulb is not connected to one of the batteries
c)
The positive terminal of one battery is not connected to the negative terminal of the next battery
d)
All are correct
|
Sonal Kul answered |
1. Due to the small gap between the batteries may result that the torch does not light up.
2. If the metal tip of the bulb may result that the torch does not light up.
3. If the positive terminal of one battery is not connected to the negative terminal of the next battery may result that the torch does not light up.
Due to these reasons torch may not light up.
2. If the metal tip of the bulb may result that the torch does not light up.
3. If the positive terminal of one battery is not connected to the negative terminal of the next battery may result that the torch does not light up.
Due to these reasons torch may not light up.
Which of the following options is FALSE?- a)A firki does not rotate in a closed area due to lack of air movement.
- b)An empty glass is not empty as it is filled with air.
- c)We see bubbles in water before it starts boiling because dissolved air is expelled out of heating.
- d)A weathercock shows the accurate speed with which the air is moving at that place.
Correct answer is option 'D'. Can you explain this answer?
Which of the following options is FALSE?
a)
A firki does not rotate in a closed area due to lack of air movement.
b)
An empty glass is not empty as it is filled with air.
c)
We see bubbles in water before it starts boiling because dissolved air is expelled out of heating.
d)
A weathercock shows the accurate speed with which the air is moving at that place.
|
|
Amar Singh answered |
Understanding Weathercocks
A weathercock, also known as a weather vane, is a device used to indicate the direction of the wind. However, it does not measure the speed of the wind accurately. Here’s why option 'D' is false:
Limitations of Weathercocks
- Weathercocks primarily indicate wind direction, not speed.
- They can only show which way the wind is blowing but do not provide quantitative data on wind velocity.
How Wind Speed is Measured
- To measure wind speed accurately, an anemometer is used.
- Anemometers consist of rotating cups or blades that turn faster with higher wind speeds, providing a numerical value for wind speed.
Common Misconceptions
- It’s a common misconception that weathercocks can indicate how fast the wind is blowing.
- While they can sway and move with the wind, their primary function is directional guidance.
Conclusion
- Therefore, option 'D' is incorrect because a weathercock does not show the accurate speed of the air movement; it only indicates the wind direction. For precise wind speed, one would need a different instrument, such as an anemometer.
A weathercock, also known as a weather vane, is a device used to indicate the direction of the wind. However, it does not measure the speed of the wind accurately. Here’s why option 'D' is false:
Limitations of Weathercocks
- Weathercocks primarily indicate wind direction, not speed.
- They can only show which way the wind is blowing but do not provide quantitative data on wind velocity.
How Wind Speed is Measured
- To measure wind speed accurately, an anemometer is used.
- Anemometers consist of rotating cups or blades that turn faster with higher wind speeds, providing a numerical value for wind speed.
Common Misconceptions
- It’s a common misconception that weathercocks can indicate how fast the wind is blowing.
- While they can sway and move with the wind, their primary function is directional guidance.
Conclusion
- Therefore, option 'D' is incorrect because a weathercock does not show the accurate speed of the air movement; it only indicates the wind direction. For precise wind speed, one would need a different instrument, such as an anemometer.
Which of the following statements about cooking of food are incorrect?a. It is a chemical and reversible change.
b. It is a physical and reversible change.
c. It is a physical and irreversible change.
d. It is a chemical and irreversible change.- a)a and b
- b)c and d
- c)a, b and c
- d)a, c and d
Correct answer is option 'C'. Can you explain this answer?
Which of the following statements about cooking of food are incorrect?
a. It is a chemical and reversible change.
b. It is a physical and reversible change.
c. It is a physical and irreversible change.
d. It is a chemical and irreversible change.
b. It is a physical and reversible change.
c. It is a physical and irreversible change.
d. It is a chemical and irreversible change.
a)
a and b
b)
c and d
c)
a, b and c
d)
a, c and d
|
|
Rohini Seth answered |
Cooking of food is an irreversible chemical change. Hence, only statement d is correct.
One centimeter on a scale is divided into 20 equal divisions. The least count of this scales is:- a)0.1 mm
- b)20 cm
- c)0.5 mm
- d)1 mm
Correct answer is option 'C'. Can you explain this answer?
One centimeter on a scale is divided into 20 equal divisions. The least count of this scales is:
a)
0.1 mm
b)
20 cm
c)
0.5 mm
d)
1 mm
|
Sharanya singhania answered |
According to the question 1 cm scale is divided into 20 equal divisions.
20 division = 1 cm
1 division = 1/20cm
= 0.05 cm
= 0.05×10 mm
= 0.5 mm
So, the least count of the scale is 0.5 mm
20 division = 1 cm
1 division = 1/20cm
= 0.05 cm
= 0.05×10 mm
= 0.5 mm
So, the least count of the scale is 0.5 mm
From a burning candle, light travels as rays which are- a)Divergent
- b)Parallel
- c)Convergent
- d)Diffused
Correct answer is option 'A'. Can you explain this answer?
From a burning candle, light travels as rays which are
a)
Divergent
b)
Parallel
c)
Convergent
d)
Diffused
|
Shiksha Academy answered |
From a burning candle , the light rays starts from a point and travel in various directions,so the light rays are divergent.
Liquids which mix with each other and do not form separate layers are called- a)Immiscible liquids
- b)Unsaturated solution
- c)Saturated solution
- d)Miscible liquids
Correct answer is option 'D'. Can you explain this answer?
Liquids which mix with each other and do not form separate layers are called
a)
Immiscible liquids
b)
Unsaturated solution
c)
Saturated solution
d)
Miscible liquids
|
EduRev Class 6 answered |
Two or more liquids which mix with each other and do not form separate layers are called miscible liquids.
Which of the following is not an insulator?- a)Plastic
- b)Glass
- c)Graphite
- d)Rubber
Correct answer is option 'C'. Can you explain this answer?
Which of the following is not an insulator?
a)
Plastic
b)
Glass
c)
Graphite
d)
Rubber
|
|
Rohini Seth answered |
Rubber, glass and plastic are insulators, but graphite is good conductor of electricity.
Chapter doubts & questions for Practice Model Test Papers - Science Olympiad Class 6 2025 is part of Class 6 exam preparation. The chapters have been prepared according to the Class 6 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Class 6 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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