Physics-
General
Easy
Question
A simple pendulum is suspended from the ceiling of a lift. When the lift is at rest its time period is 
. With what acceleration should the lift be accelerated upwards in order to reduce its period to 
? (g is acceleration due to gravity)
- 2 g
- 3 g
- 4 g
- g
The correct answer is: 3 g
Time period of simple pendulum is given by
…(i)
When the lift is moving up with an acceleration 
, then time period becomes
Here, 
…(ii)
Dividing Eq.(ii) by Eq. (i), we get
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