Oscillations · Question 19

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the most appropriate answer from the options given below :

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

Answer

(3) Both (A) and (R) are true and (R) is the correct explanation of (A).

Solution

For a simple pendulum, T = 2 lg T 1 g

T decreases when g increases and vice-versa, so Reason (R) is true.

At height h: gh = g (1 - 2hR ) < g, so g is smaller at the top of a mountain.

T is longer at the top than at the base, so Assertion (A) is true.

(A) follows directly from (R), so (R) is the correct explanation of (A).

Answer: (3)