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. 0.11
B. 0.21
C. 0.42
D. 0.1

Answer

D

Explanation

`T=2pisqrt((1)/(g))` and T '= `2pisqrt((1.21)/(g))`
`(T)/(T)` '= `sqrt(1.21) implies T'=1.1T implies Delta=0.1T`
Percentage increase in time period is `(DeltaT)/(T)xx100=(0.1T)/(T)xx100=10%`