The length of a simple pendulum executing simple harmonic motion is increased by `21%`. The percentage increase in the time period of the pendulum of increased length is

Options

A. `11%`
B. `21%`
C. `42%`
D. `10.5%`

Answer

D

Explanation

`T=2pisqrt((l)/(g))`
`implies" "(DeltaT)/(T)=(1Deltal)/(2l)`
Given, `" "(Deltal)/(l)=21%`
`:." "(DeltaT)/(T)=(1)/(2)xx21%=10.5%`