Science Olympiad Model Test Paper - 2 | Science Olympiad Class 7 PDF Download

Ans: (d)

• To find the occurrences of 7, we need to look for instances where N is before the 7 and a symbol is after it.
• In the sequence, the valid occurrences are: N7%, N7#, and N7©.
• Counting these, we find there are 3 valid instances of 7 that meet the criteria.
• Thus, the correct answer is 2 as it is the only option that fits the criteria.

Ans: (b)

Son of Amar's son – Grandson

Brother of Amar's grandson – Amar's grandson

So, Pintu is Amar's grandson.

Ans: (c)

• In this scenario, Raj is the son of Rani and the father of Sahil.
• Since Meena is identified as Sahil's mother, she is married to Raj.
• This makes Meena the daughter-in-law of Rani, as she is the wife of Rani's son.
• Thus, the correct answer is Daughter-in-law.

Ans: (a)

Let S be the starting point and E be the end point.

Ans: (a)

• F is the mother of A and E is the husband of F. 'D is the daughter of E' means 'E is the father of D'.
• F is the mother of D. D is the sister of A.
• From the given information, we cannot get to know the gender of A.

So, A can be the daughter or son of E.

Ans: (d)

The code is as follows:

R + 1 = S

U - 1 = T

N + 1 = O

In the same way, RIVER will be written as follows:

R + 1 = S

I - 1 = H

V + 1 = W

E - 1 = D

R + 1 = S

Therefore, RIVER is coded as SHWDS.

Ans: (b)

• The coding system involves shifting each letter in the word by a certain number of positions in the alphabet.
• For example, in the word SCIENTIST, each letter is shifted to create the coded version VFJHQULVU.
• Applying the same shifting pattern to EDUCATION, we find that it translates to HGVFDULRO.
• This method of encoding is consistent, making option (b) the correct answer.

Ans: (b)
The water image will be as follows:

Ans: (d)
The mirror image will be as follows:

Ans: (c)

• The bus starts by moving 7 km West.
• After turning right, it moves 5 km North.
• Then, it takes another right turn and travels 19 km East.
• To find the distance from the starting point, we can visualize the path: it ends up 12 km East and 5 km North from the starting point.
• Using the Pythagorean theorem, the distance is calculated as √(12² + 5²) = √(144 + 25) = √169 = 13 km.

Ans: (d)

Thermometer is a device which is used to measure temperature. Thermometer is made of a long narrow glass tube. with a bulb at one end. The narrow tube appears as a continuous silver line because it is filled with mercury. Mercury is a metal which is in liquid state at room temperature and it readily expands or contracts at the slightest change in temperature. So, option (4) is the correct answer.

Ans: (b)

• Uniform motion means moving at a constant speed in a straight line.
• In this case, the aeroplane flying at a speed of 600 km/h is an example of uniform motion because it maintains a steady speed.
• The other options involve changes in speed or direction, which do not represent uniform motion.
• For instance, the train and the boy cycling are both affected by their surroundings, causing variations in their speed.

Ans: (c)

When an object repeats its motion after every fixed interval of time, the motion of the object is called periodic motion or oscillatory motion. A pendulum of a clock repeats its motion after every fixed interval of time. So, it is an example of oscillatory motion.

Ans: (a)

• In Container (i), the copper coin is not magnetic, but the iron nail is, so a magnet can separate them.
• In Container (ii), the steel nail is magnetic, while the silver earring is not, allowing separation.
• In Container (iii), neither the marble nor the gold coin is magnetic, so they cannot be separated with a magnet.
• In Container (iv), the nickel coin is not magnetic, but the steel nail is, allowing for separation.
• Thus, a magnet can effectively separate the objects in containers (i) and (ii) only.

Ans: (a)

• Initially, X is 10 m ahead of Y.
• Y runs 60 m to catch up with X, meaning he covers the distance of X's lead plus the distance X runs in that time.
• Let the speed of X be Vx and the speed of Y be Vy. In the time Y runs 60 m, X runs (60 - 10) m = 50 m.
• Thus, the ratio of their speeds is Vx:Vy = 50:60 = 5:6. However, since we need the ratio of Y's speed to X's speed, we flip it to get Vy:Vx = 6:5.

Ans: (a)

When we pour cold water over a tin can filled with boiled water, the can gets distorted because the air inside the can gets condensed and creates low pressure. The higher pressure from outside distorts the shape of the can.

Ans: (b)

• The pressure on the top of the wings is low during takeoff, which helps the plane to lift.
• Conversely, the pressure below the wings is high, pushing the plane upwards.
• This difference in pressure creates lift, allowing the airplane to ascend into the air.
• Understanding this concept is crucial for grasping how airplanes achieve flight.

Ans: (d)

The angle between incident ray and reflected ray is equal to the sum of the angle of incident and the angle of reflection. Since both of them are equal, this should be twice the angle of incident, not less than twice.

Ans: (c)

• Indicators are substances that detect the acidic or basic nature of a substance by a change in its colour.
• Phenolphthalein is colourless in neutral and acidic solutions and pink in basic solutions.

Hence, the observation stated in option (c) is incorrect.

Ans: (b)

• Stretching of a rubber band is a physical change, which is reversible.
• Cutting of paper is a physical change, which is irreversible.
• Burning of wax is a chemical change and melting of wax is a physical change. Therefore, burning of candle involves both physical and chemical changes.
• Cooking of food is a chemical change, which is permanent and irreversible.
  Hence, option (b) is correct.

Ans: (a)

The department of meteorology is a government department. The meteorological department measures the elements of weather and keeps their record. Meteorologists use data from satellites and analyse the data to forecast about the weather.

Ans: (d)

Patanwadi, Marwari and Dumba are three important sheep breeds of Gujarat.

Hence, the information in option (d) is incorrect.

Ans: (d)

Statement 2 is incorrect. Decomposers, and not animals, complete the process of nutrient recycling, thus maintain the concentration of soil nutrients.

Ans: (c)

• The sublimation method is used to separate substances that can change directly from a solid to a gas without becoming liquid.
• In this case, Camphor and Iodine can sublimate, while Common salt and Sugar cannot.
• Thus, mixtures containing Common salt or Sugar cannot be separated by sublimation.
• Among the options, only III (Camphor + Iodine) cannot be separated by sublimation, making it the correct answer.

Ans: (c)

Platelets are responsible for clotting or coagulation of blood. In case of an injury, the blood clots after some time. This prevents excess loss of blood. Clotting of blood is a defence mechanism in the body.

Ans: (a)
Non-metals combine with oxygen to form acidic oxides. 

Ans: (c)
Ductility is the property of a metal associated with the ability to be hammered thin or stretched into wire without breaking.

Ans: (d)
More reactive metals like sodium and potassium react violently with dilute acids. Reaction is slower for less reactive metals and, copper, silver and gold do not react with acids.

Ans: (d)
Iron reacts with moist air to form rust (Fe₂O₃ · xH₂O). Since, in test tube 1, air is dry and test tube 3 has a layer of oil on the top of water, so iron (paper clip) does not come in the direct contact of moist air, and does not get rust.

Ans: (c)

• Lohi is actually a breed associated with Haryana, not Uttar Pradesh. This makes option (c) the incorrect match.
• The other options correctly match the breeds with their respective regions: Bakharwal is from Jammu and Kashmir, Nali is from Haryana, and Patanwadi is from Gujarat.
• Understanding the geographical distribution of these breeds is important for recognizing their origins.

Ans: (a)

• Villi are the small, finger-like projections found on the inner surface of the small intestine, which help in nutrient absorption.
• The stomach is responsible for secreting mucus, hydrochloric acid, and digestive juices that aid in digestion.
• The other options do not correctly fill the blanks as they either provide incorrect terms or measurements.
• Thus, option (a) is the correct choice as it accurately completes the statements.

Ans: (d)

• The statement (i) is correct because the white fur of polar bears actually helps them blend into the snow, making it hard for both prey and predators to spot them.
• Statement (ii) is incorrect; polar bears have two layers of fur: a dense undercoat and a longer outer layer, which together keep them warm.
• Statement (iii) is correct; their large paws distribute their weight, allowing them to walk on snow without sinking.
• Statement (iv) is correct; polar bears have a strong sense of smell that aids them in locating prey.

Ans: (c)

The test confirms that the gas was carbon dioxide. When passed through lime water it turns it milky because of the formation of calcium carbonate, which is a white compound insoluble in water.

The following reaction occurs:

Ans: (d)

• Collection of rainwater for future use is called rainwater harvesting.
• Drip irrigation is a method through which maximum number of plants can be irrigated with a minimum quantity of water. For this, pipelines are laid throughout the rows of plants with holes at strategic points to release water.
• In roof irrigation, water is gathered on the roof for irrigation.
• All these methods help in saving water, which is an important but scarce resource.

Ans: (c)
The hardest substance known is diamond. Diamond is an allotrope of carbon, i.e., a non-metal.

Ans: (b)

• The correct answer is (b) because flowers that rely on wind for pollination typically do not have bright petals. Instead, they often have small or no petals to avoid attracting insects.
• These flowers produce huge quantities of pollen grains to increase the chances of successful pollination.
• Pollen grains from wind-pollinated flowers are usually light and non-sticky, allowing them to be carried easily by the wind.
• Additionally, they have well exposed stamens and stigma to maximize the chances of catching the wind-borne pollen.

Ans: (b)
As the solution turns blue litmus red so, it is an acidic solution. On burning non-metals, it forms acidic oxides. Therefore, the substance which Rahul burned must be a non-metal. Since, Mg, Na and Fe are metals while S is a non-metal, so the burning substance is sulphur (S).

Ans: (a)
Chalk powder and water can be separated by sedimentation and decantation while salt and water can be separated by evaporation.

Ans: (d)
Non-metals used in fertilisers are nitrogen and phosphorus; non-metal used in water purification process is chlorine ; non- metals used in crackers are sulphur and phosphorus.

Ans: (c)

Dark clothes absorb more heat and keep one comfortable in winter. Woollen clothes are used in winter season because wool is a poor conductor of heat. In addition to it, air gets trapped in woollen fibre to further increase the poor conductivity of wool. This prevents the radiation of heat of our body to the surrounding and prevents the cold from surroundings to affect our body.

Ans: (d)

• The question asks for the incorrect match between an animal and its adaptive feature.
• Snow leopards have thick fur to keep warm in cold climates, which is correct.
• Dolphins use blow holes to breathe, which is also accurate.
• Deer have long ears to detect predators, making this pairing correct as well.
• However, camels do not excrete a large amount of urine; instead, they conserve water and can tolerate dehydration, making option (d) the incorrect match.

Ans: (d)

• Step 1: Water vapor from water bodies and plants enters the air (ii).
• Step 2: This vapor cools at higher altitudes (iii).
• Step 3: The cooled vapor forms clouds (vi).
• Step 4: Water droplets in clouds combine to create larger droplets (i).
• Step 5: These droplets fall as rain (v).
• Step 6: Finally, the rainwater returns to water bodies (iv).
  This sequence accurately represents the water cycle, showing how water moves from the ground to the atmosphere and back again.

Ans: (a)

• Air becomes thinner as you go higher in altitude. This means that there are fewer air molecules in a given volume.
• As you climb mountains or fly in an airplane, you may notice that it becomes harder to breathe; this is because the oxygen level decreases with altitude.
• The thinning of air affects various activities, such as sports and aviation, where less air pressure can impact performance.
• In summary, as altitude increases, the air density decreases, making it thinner.

Ans: (a)

The centre of the cyclone is called the 'eye'. A cyclone may be 10 km to 15 km high. It is a rotating mass of air. The diameter of the cyclone eye may vary from 10 km to 30 km. The eye of a cyclone is the calm area, but around the eye, air may move with high speeds such as 150 km/h to 250 km/h.

Ans: (a)

• Complete flowers have all four main parts: sepals, petals, stamens, and carpels.
• In option (a), Petunia, Hibiscus, and Mustard all possess these four parts, making them complete flowers.
• Options (b), (c), and (d) include plants that either lack some parts or are incomplete flowers.
• Thus, the correct answer is (a) as it includes only complete flowers.

Ans: (d)

• Both sericulture and moriculture are activities related to production of silk.
• Sericulture is the general term used for rearing of silkworms for commercial production of silk.
• Moriculture is cultivation of mulberry because the silkworm Bombyx mori feeds on mulberry leaves.

Therefore, both statements I and II are incorrect.

Ans: (d)
Aluminium is used for making cooking utensils because it has high melting point and good thermal conductivity. 

Ans: (d)
Nickel, silver and chromium are active electrodes so they can be used for electroplating the articles but sodium is not used for electroplating.

Ans: (d)

• Skimmer is a device used to remove sludge, and it can be correctly replaced by a scraper in this context.
• The term anaerobic refers to bacteria that do not require oxygen, while aerobic refers to those that do. In the aeration tank, aerobic bacteria are typically used.
• Options (a) and (b) suggest incorrect replacements that do not align with the processes described.
• Option (c) is correct in stating that "increased" and "light" are appropriately used, but it does not address the main focus of the question.

Ans: (c)

A kind of plant grown and cultivated on a large scale at a place is called crop. The first step before growing crops is preparation of the soil. For growing a crop, sufficient sunlight, water and nutrients from the soil are essential. Damaged seeds would float on top of the water.