Question

Assertion (A): Cooking becomes difficult on the top of a mountain.
Reason (R): At higher altitude the pressure is less, and hence, the boiling point of water decreases with altitude.

• A. A and R are true and R is the correct explanation of A.
• B. A and R are true, but R is not the correct explanation of A.
• C. A is true but R is false.
• D. Both A and R are false.

Answer 1

The correct option is A

A and R are true and R is the correct explanation of A.

Explanation of assertion:

1. At higher altitudes, atmospheric pressure decreases, due to which the boiling point of water also decreases.
2. Hence, water boils at a lower temperature, due to which cooking food becomes difficult.

Explanation of Reason:

1. The temperature at which the vapor pressure of a liquid becomes equal to the atmospheric pressure is called the boiling point of the liquid.
2. At higher altitudes, atmospheric pressure decreases, due to which the vapor pressure becomes equal to the atmospheric pressure at a lower temperature. As a result, the boiling point of water also decreases.

Thus, A and R are true and R is the correct explanation of A.
Hence, Option (A) is the correct answer.