Test: Class 10 General Science NCERT Based - 2


25 Questions MCQ Test Science & Technology for UPSC CSE | Test: Class 10 General Science NCERT Based - 2


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This mock test of Test: Class 10 General Science NCERT Based - 2 for UPSC helps you for every UPSC entrance exam. This contains 25 Multiple Choice Questions for UPSC Test: Class 10 General Science NCERT Based - 2 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Class 10 General Science NCERT Based - 2 quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Test: Class 10 General Science NCERT Based - 2 exercise for a better result in the exam. You can find other Test: Class 10 General Science NCERT Based - 2 extra questions, long questions & short questions for UPSC on EduRev as well by searching above.
QUESTION: 1

Regarding the covalent bonds, which of the following statements is/are incorrect?

1. Bonds which are formed by the sharing of an electron pair between two atoms are known as Covalent Bonds.

2. Covalently bonded molecules are seen to have weak bonds within the molecule, but intermolecular forces are large.

3. Covalent compounds are poor conductors of electricity.

Select the correct answer using the code given below:

Solution:
  • The bonds which are formed by the sharing of an electron pair between two atoms are known as covalent bonds. Since the electrons are shared between atoms and no charged particles are formed, such covalent compounds are generally poor conductors of electricity as they do not have a free electron to move.

  • Covalently bonded molecules are seen to have strong bonds within the molecule, but intermolecular forces are small. This gives rise to the low melting and boiling points of these compounds.

QUESTION: 2

Which of the following structures are allotropes of carbon?

1. Diamond

2. Graphite

3. Fullerene

Select the correct answer using the code given below:

Solution:
  • Diamond and Graphite are formed by carbon atoms, the difference lies in the manner in which the carbon atoms are bonded to one another. In Diamond, each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure.

  • In graphite, each carbon atom is bonded to three other carbon atoms in the same plane giving a hexagonal array.

  • Fullerenes from another class of carbon allotropes. The first one to be identified was C-60 which has carbon atoms arranged in the shape of a football.

QUESTION: 3

Regarding ethanol, which of the following statements is incorrect?

Solution:
  • Ethanol is a good solvent, it is also used in medicines such as tincture iodine, cough syrups, and many tonics. When large quantities of ethanol are consumed, it tends to depress the central nervous system.

  • This results in lack of coordination, mental confusion, drowsiness, lowering of the normal inhibitions, and finally stupor. Consumption of ethanol tends to slow metabolic processes.

  • Alcohol contains empty calories and has no nutritional value. It often contributes to malnutrition because the high levels of calories in most alcoholic drinks can account for a large percentage of your daily energy requirementsEthanol is liquid at room temperature. Ethanol is commonly called alcohol and is the active ingredient of all alcoholic drinks.

QUESTION: 4

With reference to alcohol, consider the following statements:

1. Sugarcane juice can be used to prepare molasses which is fermented to give alcohol (ethanol).

2. Alcohol can be used as an additive in petrol since it is a cleaner fuel.

Which of the statements given above is/are correct?

Solution:
  • Sugarcane plants are one of the most efficient convertors of sunlight into chemical energy.

  • Sugarcane juice is used to prepare molasses which is fermented to give alcohol (ethanol). Some countries now use alcohol as an additive in petrol since it is a cleaner fuel which gives rise to only carbon dioxide and water on burning in sufficient air (oxygen).

  • As the Alcohol molecule contains oxygen, it allows the engine to more completely combust the fuel, resulting in fewer emissions and thereby reducing the occurrence of environmental pollution. Since alcohol is produced from plants that harness the power of the sun, it is also considered as renewable fuel.

QUESTION: 5

Which of the following elements are responsible for the hardness of water?

Solution:
  • Bathing foam forms an insoluble substance (scum), this is caused by the reaction of soap with the calcium and magnesium salts, which cause the hardness of water. This problem is overcome by using another class of compounds called detergents as cleansing agents.

  • Detergents are generally ammonium or sulphonate salts of long chain carboxylic acids. The charged ends of these compounds do not form insoluble precipitates with the calcium and magnesium ions in hard water. Thus, they remain effective in hard water. Detergents are usually used to make shampoos and products for cleaning clothes.

QUESTION: 6

Match List-I with List-II and select the correct answer:

List-I (Scientist)

A. Johann Wolfgang Döbereiner

B. John Newlands

C. Dmitri Ivanovich Mendeléev

D. Henry Moseley

List-II (Work/theory)

1. Law of Octaves

2. Coined the term ‘Triads’

3. Modern Periodic Table

4. Early development of the periodic table of elements.

Solution:
  • In the year 1817, Johann Wolfgang Döbereiner, a German chemist, tried to arrange the elements with similar properties into groups. He identified some groups having three elements each. So he called these groups 'triads'.

  • In 1866, John Newlands, an English scientist arranged the then known elements in the order of increasing atomic masses. He compared the table to the octaves found in music. Therefore, he called it the ‘Law of Octaves’.

  • The main credit for classifying elements goes to Dmitri Ivanovich Mendeléev, a Russian chemist. He was the most important contributor to the early development of a Periodic Table of elements wherein the elements were arranged on the basis of their fundamental property, the atomic mass, and also on the similarity of chemical properties.

  • In 1913, Henry Moseley showed that the atomic number of an element is a more fundamental property than its atomic mass as described below.

Accordingly, Mendeléev’s Periodic Law was modified and atomic number was adopted as the basis of the Modern Periodic Table.

QUESTION: 7

With reference to Mendeléev’s Periodic Table, consider the following statements:

1. Mendeléev arranged the elements in the order of their increasing atomic masses.

2. Mendeléev left some gaps in Periodic Table

Which of the statements given above is/are correct?

Solution:
  • Mendeleev examined the relationship between the atomic masses of the elements and their physical and chemical properties. He observed that most of the elements got a place in a Periodic Table and were arranged in the order of their increasing atomic masses.

  • It was also observed that there occurs a periodic recurrence of elements with similar physical and chemical properties. Mendeléev left some gaps in his Periodic Table. Instead of looking upon these gaps as defects, Mendeléev boldly predicted the existence of some elements that had not been discovered at that time.

QUESTION: 8

Regarding the limitations of Mendeléev’s classification, consider the following statements:

1. The Position of Hydrogen was ambiguous.

2. Isotopes of all elements posed a challenge to Mendeleev’s Periodic Law.

3. The atomic masses do not increase in a regular manner in going from one element to the next.

Which of the statements given above is/are correct?

Solution:
  • Certainly, no fixed position can be given to hydrogen in the Periodic Table. This was the first limitation of Mendeléev’s Periodic Table. He could not assign a correct position to hydrogen in his Table.

  • Isotopes were discovered long after Mendeléev had proposed his periodic classification of elements.

  • Isotopes of an element have similar chemical properties, but different atomic masses. Thus, isotopes of all elements posed a challenge to Mendeleev’s Periodic Law. Another problem was that the atomic masses do not increase in a regular manner in going from one element to the next. So it was not possible to predict how many elements could be discovered between two elements — especially when we consider the heavier elements.

QUESTION: 9

Regarding the modern periodic table, consider the following statements:

1. Properties of elements are a periodic function of their atomic number.

2. There are 7 groups and 18 periods.

Which of the statements given above is/are correct?

Solution:

1. The Modern Periodic Law states: 'Properties of elements are a periodic function of their atomic number'.

2. The atomic number gives us the number of protons in the nucleus of an atom and this number increases by one in going from one element to the next.

3. Elements, when arranged in order of increasing atomic number Z, lead us to the classification known as the Modern Periodic Table. Prediction of properties of elements could be made with more precision when elements were arranged on the basis of increasing atomic number.

4. The Modern Periodic Table has 18 vertical columns known as ‘groups’ and 7 horizontal rows known as ‘periods’.

QUESTION: 10

Regarding the modern periodic table, which of the following statements is incorrect?

Solution: As the effective nuclear charge acting on the valence shell electrons increases across a period, the tendency to lose electrons will decrease. Down the group, the effective nuclear charge experienced by valence electrons is decreasing because the outermost electrons are farther away from the nucleus.

Therefore, these can be lost easily. Hence metallic character decreases across a period and increases down a group.

QUESTION: 11

Match List-I with List-II and select the correct answer:

List-I (Plant hormones)

A. Auxin

B. Gibberellins

C. Cytokinins

D. Abscisic acid

LIST-II (Effects)

1. Promote cell division

2. Inhibits growth

3. It helps the cells to grow longer

4. Help in the growth of the stem

Solution: Different plant hormones help to coordinate growth, development and responses to the environment. They are synthesised at places away from where they act and simply diffuse to the area of action.

1. When growing plants detect light, a hormone called Auxin, synthesised at the shoot tip, helps the cells to grow longer.

2. Another example of plant hormones are Gibberellins which help in the growth of the stem.

3. Cytokinins promote cell division, and it is natural that they are present in greater concentration in areas of rapid cell division, such as in fruits and seeds. These are examples of plant hormones that help in promoting growth.

4. But plants also need signals to stop growing. Abscisic acid is one example of a hormone which inhibits growth. Its effects include wilting of leaves.

QUESTION: 12

Consider the following hormones:

1. Adrenaline

2. Testosterone

3. Estrogen

Which of the above hormones, prepare the human body for fighting or running instantaneously?

Solution: 1. Adrenaline is secreted directly into the blood and carried to different parts of the body and is known as "fight or flight" Hormone.

2. The target organs or the specific tissues on which it acts include the heart. As a result, the heart beats faster, resulting in supply of more oxygen to our muscles.

3. The blood to the digestive system and skin is reduced due to contraction of muscles around small arteries in these organs. This diverts the blood to our skeletal muscles.

4. The breathing rate also increases because of the contractions of the diaphragm and the rib muscles. All these responses together enable the animal body to be ready to deal with the situations like fighting and running.

5. Testosterone and estrogen are the reproductive hormones such animal hormones are part of the endocrine system which constitutes a second way of control and coordination in our body.

QUESTION: 13

Consider the following pairs:

1. Thyroid Gland: Thyroxine hormone

2. Pituitary Gland: Growth hormone

3. Pancreas: Insulin

Which of the pairs given above is/are correctly matched?

Solution: 1. Thyroxine regulates carbohydrate, protein and fat metabolism in the body so as to provide the best balance for growth. Iodine is necessary for the thyroid gland to make thyroxine hormone. In case iodine is deficient in our diet, there is a possibility that we might suffer from goitre.

2. Growth hormone is one of the hormones secreted by the pituitary. As its name indicates, growth hormone regulates growth and development of the body. If there is a deficiency of this hormone in childhood, it leads to dwarfism.

3. Insulin is the hormone which is produced by the pancreas and helps in regulating blood sugar levels. If it is not secreted in proper amounts, the sugar level in the blood rises causing many harmful effects.

QUESTION: 14

Consider the following statements:

1. Voluntary actions are controlled by Hindbrain.

2. Hearing, Smell is controlled by Fore-Brain.

Which of the above statements is/are Correct?

Solution:
  • Medulla in HindBrain controls involuntary function such as blood pressure, salivation, vomiting.

  • Forebrain is the main thinking part of the brain. It has regions which receive sensory impulses from various receptors. Separate areas of the forebrain are specialised for hearing, smell and sight and so on.

QUESTION: 15

Consider the following pairs:

1. Benzoic acid formed in our muscles during a physical activity leads to cramps.

2. The rate of breathing in aquatic organisms is much faster than that in terrestrial organisms.

Which of the statements given above is/are correct?

Solution:
  • In anaerobic respiration, there is a lack of oxygen in our muscles. Pyruvate instead of breaking down to form carbon-dioxide and water, it disintegrates into lactic acid and its accumulation in our muscles leads to cramps.

  • Aquatic organisms breathe much faster than terrestrial organisms as the amount of oxygen dissolved in water is less as compared to the amount of oxygen in air. To compensate for this, the breathing rate of aquatic organisms is faster.

QUESTION: 16

Consider the following statements:

1. Plants store carbohydrates in the form of glycogen.

2. Human beings store carbohydrates in the form of starch.

Which of the statements given above is/are incorrect?

Solution:
  • Carbon and energy requirements of an autotrophic organism are fulfilled by photosynthesis. It is the process by which autotrophs take in substances from the outside and convert them into stored forms of energy.

  • This material is taken in the form of carbon dioxide and water which is then converted into carbohydrates, in the presence of sunlight and chlorophyll. The carbohydrates which are not used immediately are stored in the form of starch, which serves as the internal energy reserve to be used as and when required by the plant.

 

QUESTION: 17

Consider the following events about Photosynthesis:

1. Absorption of light energy by chlorophyll.

2. Reduction of carbon dioxide to carbohydrates.

Which of the statements given above is/are correct?

Solution:
  • Photosynthesis is a process by which plants convert inorganic materials such as carbon dioxide and oxygen into carbohydrates using sunlight. This process occurs in the chloroplast of plants.

  • Chlorophyll traps the sunlight to reduce carbon dioxide and water into oxygen and Glucose which allows the plant to grow. Hence, Statement 1 and 2 are Correct. Water splits into oxygen, hydrogen ions, and electrons to replace the lost electrons in light-dependent reactions. As hydrogen ions pass through ATP synthase, ATP is formed.

  • 6CO2 + 6H2O (chlorophyll + sunlight) → C6H12O6 + 6O2 (Glucose) Carbon gets into the leaf through minute pores in leaves called stomata and water goes into the plant through its roots. Oxygen gets out of the cell through the stomata.

QUESTION: 18

Consider the following statements about Digestion:

1. The secretion is done by the small intestine.

2. Hydrochloric acid inhibits the functioning of Pepsin.

3. The Mucus protects the inner lining of the stomach from the action of the acid.

Select the correct answer using the code given below:

Solution:
  • The digestion functions are taken care of by the gastric glands present in the wall of the stomach. These release Hydrochloric acid, a protein digesting enzyme called pepsin, and mucus.

  • The Hydrochloric acid creates an acidic medium which facilitates the action of the enzyme ‘pepsin’. The mucus protects the inner lining of the stomach from the action of the acid, that causes "acidity" in adults.

QUESTION: 19

With reference to the respiration in human beings, consider the following statements:

1. Cartilage blocks the air passage.

2. Haemoglobin has a very high affinity for oxygen.

3. Fine hairs in the nostril traps harmful microbes in respiration.

Which of the statements given above is/are correct?

Solution:
  • In human beings, air is taken into the body through the nostrils. The air passing through the nostrils is filtered by fine hairs and harmful microbes are trapped. The passage is also lined with mucus which helps in this process.

  • Rings of cartilage are present in the throat which ensure that the air passage does not collapse. Once oxygen enters the blood from the lungs, it is taken up by haemoglobin (Hb) in the red blood cells and forms oxyhaemoglobin thereby oxygen gets circulated in the entire body.

QUESTION: 20

Regarding blood pressure, consider the following statements:

1. The Blood pressure is higher in Veins than in Arteries.

2. The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg. 3. Blood pressure is measured with an instrument called sphygmomanometer.

Which of the statements given above is/are correct?

Solution:
  • The force that blood exerts against the wall of a vessel is called blood pressure. This pressure is much greater in arteries than in veins as arteries carry oxygenated blood from the heart to other parts of the body that emerge at high pressure and remain the same.

  • The pressure of blood inside the artery during ventricular systole (contraction) is called systolic pressure and pressure in artery during ventricular diastole (relaxation) is called diastolic pressure. The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg. Blood pressure is measured with an instrument called sphygmomanometer.

QUESTION: 21

Regarding 'reproduction', consider the following statements:

1. The basic event in reproduction is the creation of a DNA copy.

2. Two copies of DNA in a reproducing cell are completely identical to each other.

3. Reproduction is linked to the stability of the population of species.

Which of the statements given above is/are correct?

Solution:
  • The DNA in a cell nucleus is an information source for making proteins. If the information is changed, different proteins will be made. Different proteins will eventually lead to altered body designs.

  • Therefore, a basic event in reproduction is the creation of a DNA copy. Cells use chemical reactions to build copies of their DNA. This creates two copies of the DNA in a reproducing cell, that will need to be separated from each other. No bio-chemical reaction is absolutely reliable.

  • Therefore, it is only to be expected that the process of copying the DNA will have some variations each time. As a result, the DNA copies generated will be similar, but may not be identical to the original.

  • A population of organisms fill well-defined places, or niches, in the ecosystem, by using their ability to reproduce. The consistency of DNA copying during reproduction is important for the maintenance of body design features that allows the organism to use that particular niche. Reproduction is therefore linked to the stability of the population of species.

QUESTION: 22

With reference to the male and female gametes, consider the following statements:

1. A female gamete is smaller than a male gamete and likely to be motile.

2. Male gametes are large and contain food-stores.

Which of the statements given above is/are correct?

Solution: Conventionally, the motile germ cell is called the male gamete and the germ-cell containing the stored food is called the female gamete. One germ-cell is large and contains the food-stores while the other is smaller and likely to be motile.

QUESTION: 23

With reference to the reproductive parts of flower, consider the following statements:

1. Stamen produces pollen grains.

2. The Swollen part of Carpel is known as ovary.

3. Cross Pollination involves transfer of pollen grains to the same flower.

Which of the statements given above is/are correct?

Solution:
  • Stamen is the male reproductive part and it produces pollen grains that are yellowish in colour.

  • Carpel is present in the centre of a flower and is the female reproductive part. It is made up of three parts.

  • The swollen bottom part is the ovary, the middle elongated part is the style and the terminal part which may be sticky is the stigma. The ovary contains ovules and each ovule has an egg cell.

  • The pollen needs to be transferred from the stamen to the stigma. If this transfer of pollen occurs in the same flower, it is referred to as self-pollination. On the other hand, if the pollen is transferred from one flower to another, it is known as cross pollination. This transfer of pollen from one flower to another is achieved by agents like wind, water or animals.

QUESTION: 24

Regarding the male reproductive system, consider the following statements:

1. Sperm formation requires a higher temperature than the normal body temperature.

2. Testosterone triggers Changes at Puberty.

Which of the statements given above is/are correct?

Solution:
  • The formation of germ-cells or sperms takes place in the testes. These are located outside the abdominal cavity in the scrotum because sperm formation requires a lower temperature than the normal body temperature.

  • The role of the testes in the secretion of the hormone, testosterone, is to regulate the formation of sperms, and brings about changes in appearance, seen in boys at the time of puberty such as broadening of chest. In adolescent boys, sometimes, the muscles of the growing Voice Box go out of control and the voice becomes hoarse.

QUESTION: 25

Regarding the female reproductive system, consider the following statements:

1. Fertilization takes place in the female's Uterus.

2. The embryo gets nutrition from the mother’s blood with the help of a special tissue called placenta.

Which of the statements given above is/are incorrect?

Solution:
  • The ovary gets produced in the ovaries in the female. The fertilization of gametes takes place in the fallopian tube. The fertilised egg, the zygote, gets implanted in the lining of the uterus, and starts dividing. The embryo gets nutrition from the mother’s blood with the help of a special tissue called placenta.

  • This is a disc which is embedded in the uterine wall. It contains villi on the embryo’s side of the tissue. On the mother’s side are blood spaces, which surround the villi.