A pendulum is suspended in a ligt and its period of oscillation when the lift is stationary is `T_(a)`. What must be the accleraion of the lift for the period of oscillation of the pendulum to be `T_(0)//2`?

Options

A. `2g` downward
B. `2g` upward
C. `3g` downward
D. `3g` upward

Answer

D

Explanation

`T_(0) = 2pisqrt((l)/(g_(eff)))`….(i)
Now `(T_(0))/(2) = 2pisqrt((l)/(g + a))`….(ii)
`rArr (g +a )/(g) = 4 rArr a = 3g` (upwards)