Simple pendulum is executing simple harmonic motion with time period `T`. If the length of the pendulum is increased by `21%`, then the increase in the time period of the pendulum of the increased length is:

Options

A. 0.1 s
B. 0.2 s
C. 0.4 s
D. 0.15 s

Answer

B

Explanation

`(T_(2))/(T_(1))=sqrt((l_(2))/(l_(1)))=sqrt(1.21)`
`therefore (T_(2))/(T_(1))=1.1`
`(T_(2)-T_(1))/(T_(1))=0.1`
`therefore T_(2)-T_(1)=0.1xx2=0.2s`