Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R…

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R

Assertion A: A pendulum clock when taken to Mount Everest becomes fast.

Reason R: The value of g (acceleration due to gravity) is less at Mount Everest than its value on the surface of earth.

In the light of the above statements, choose the most appropriate answer from the options given below 

  1. Both A and R are correct and R is the correct explanation of A
  2. Both A and R are correct but R is not the correct explanation of A
  3. A is correct but R is not correct
  4. A is not correct but R is correct

Solution

Time period of a pendulum is given by T=2πLg, where L is the length of the pendulum and g is the acceleration due to gravity.

As, T∝1g, so the time period of vibration of the pendulum clock increases i.e. it starts taking more time to complete each vibration. Therefore, the pendulum clock becomes slow.

The acceleration due to gravity decreases with height h h≪R above the surface as:

g'=g1-hR 

Thus, value of g is less at Mount Everest than its value on the surface of earth.

Hence, assertion is wrong, but reason is correct.

Asked in: JEE Main 2023 (24 Jan Shift 2)

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