Assertion : The amplitude of an oscillation pendulum decreases gradually with time
Reason : The frequency of the pendulum decrease with time

Options

A. If the both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true and the reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false statements.

Answer

C

Explanation

The amplitude of an oscillating pendulum decreases with time because of friction due to air . Frequency of simple pendulum is given by
`f=1/(2pi)sqrt(g/l)`
Which is independent of amplitude and so even though the frequency remains the same, the amplitude keeps on decreasing till it becomes zero.