J & K CET Medical
J & K - CET Medical Solved Paper-2000
question_answer
A simple pendulum suspended from the ceiling of a train has a period T when the train is at rest. When the train is accelerating with a uniform acceleration the time period of simple pendulum will:
A) decrease
B) increase
C) remain unchanged
D) become infinite
Correct Answer:
A
Solution :
The periodic time of a simple pendulum of length I is given by \[T=2\pi \sqrt{\frac{l}{g}}\] In accelerated frame, pseudo force of magnitude\[-ma\]also acts, hence net acceleration increases. Since, \[T\propto \frac{1}{acceleration}\] \[\therefore \]Time period decreases.