Question 1

Assertion (A) Alcohol rather than mercury is used in a thermometer to measure a temperature of - 60 C. Reason (R) Alcohol has a lower freezing point than mercury.

Accepted Answer

We know that, mercury freezes at -39 C, while alcohol freezes at a point far below - 100 C. So, alcohol is used to measure lower temperatures. Similarly, mercury boils at 357 C, while alcohol boils at 78 C. So, mercury is used to measure high temperature.

Question 2

Assertion (A) Tides indicate the regular and periodic rise and fall in sea level. Reason (R) Tides are caused by the gravitational pull of the Moon and sea level.

Accepted Answer

Both the assertion and reason are true but reason are true but reason is not the correct explanation of assertion.

Question 3

Assertion (A) Graphite is slippery and used as a lubricant. Reason (R) Graphite has free electrons.

Accepted Answer

In graphite, each carbon atoms is linked to three other carbon atoms, while one electron in the carbon atom is delocalised. So, graphite has free electrons and it is also used as a lubricant but reason does not explains assertion.

Question 4

Assertion (A) When common salt is kept open, it absorbs moisture from the air. Reason (R) Common salt contains magnesium chloride.

Accepted Answer

We know that, common salt contains magnesium chloride. Therefore, it absorbs moisture from the air.

Question 5

Assertion (A) The steam engine was invented by James Watt. Reason (R) There was a problem of taking out water from flooded mines.

Accepted Answer

Assertion is correct but reason is false.

Question 6

Assertion (A) We prefer to wear white clothes in winter. Reason (R) White clothes are good reflectors of heat.

Accepted Answer

We prefer coloured/dark clothes in winter as they absorb heat but given reason is true for white clothes.

Question 7

Assertion (A) Earthworms are not good for agriculture. Reason (R) Earthworms break down the soil into fine particles and make it soft.

Accepted Answer

Earthworms are good for agriculture as they make the soil fertile. Therefore, assertion is false but the reason is true.

Question 8

Assertion (A) Mercury is the farthest planet from the Sun. Reason (R) Mercury is the smallest planet in the entire solar system.

Accepted Answer

We know that, mercury is the smallest planet but it is not the farthest planet.

Question 9

Assertion (A) Red, green colour blindness occurs with more frequency in males than in females. Reason (R) Females have two X-chromosomes and males have one.

Accepted Answer

Both assertion and reason are correct and reason is correct explanation for the assertion as if mutation for colour blindness occurs in one X-chromosome, female have one normal chromosome.

Question 10

Assertion (A) Indus Valley people knew the art of navigation. Reason (R) Indus Valley seals indicate prevalence of overseas trade.

Accepted Answer

Indus Valley people knew the art of navigation but the reason that the seals of that time indicate prevalence of overseas trade is false.

Question 11

Assertion (A) A person with blood group-O is supposed to be an universal donor. Reason (R) Group-O does not contain any anti-gens.

Accepted Answer

We know that the person with blood group-O is the universal blood donor but group-O positive blood group contains anti-gens for Rh factor.

Question 12

Assertion (A) Most of the Himalayan rivers are perennial. Reason (R) They are fed by melting snow.

Accepted Answer

Most Himalayan rivers are perennial because they are fed by the melting snow throughout the year.

Question 13

Assertion (A) An iron ball floats on mercury but gets immersed in water. Reason (R) The specific gravity of iron is more than that of mercury.

Accepted Answer

Iron has specific gravity less than that of mercury but more than that of water so, floats on mercury but gets immersed in water.

Question 14

Assertion (A) Noise pollution is an unwanted accumulation of noise in the atmosphere. Reason (R) It interferes with communication.

Accepted Answer

Noise pollution is an unwanted accumulation of noise in the atmosphere as it interferes with communication.

Question 15

Assertion (A) Akbar found Din-e-Illahi. Reason (R) He was motivated by self glorification.

Accepted Answer

Assertion correct because Din-e-Illhi was founded by Akbar but the reason is false.

Question 16

Assertion (A) Amartya Sen was awarded the nobel prize for Economics. Reason (R) Amartya Sen has made an invaluable contribution in the field of developmental Economics.

Accepted Answer

Both A and R are true and because of the reason the assertion is true.

Question 17

Assertion (A) The world bank is a leading International Financial Institution. Reason (R) Ever, since its formation, it has played a major role in disbursing aid and support to economies across the world.

Accepted Answer

Both A and R are true and because of the reason the assertion is true.

Question 18

Assertion (A) In the Indian democratic system, the cabinet ministers are appointed by the President. Reason (R) The Prime Minister plays an advisory role.

Accepted Answer

Both A and R are true but R is not the reason for A.

Question 19

Assertion (A) India is a country of diverse cultures, customs and languages. Reason (R) What we now call India is the modern version of Bharat.

Accepted Answer

Both A and R are true but R is not the reason for A.

Question 20

Assertion (A) The ozone layer present in the upper atmosphere of Earth is beneficial for sustaining life on the Earth. Reason (R) The ozone layer blocks the harmful ultraviolet rays from the Sun and thus proctects life on the Earth.

Accepted Answer

Both A and R are true and R is the reason for A.

Assertion and Reason Questions