## Assertion and Reason

#### Assertion and Reason

Direction: Choose the correct alternative from the following options as given below for the Assertion (A) and Reason (R) given in each of the questions.

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.

1. 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.

##### Correct Option: A

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.

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

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

##### Correct Option: C

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

1. 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.

1. 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.

##### Correct Option: A

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.

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

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

##### Correct Option: D

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

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

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

##### Correct Option: D

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