Q.
Two simple pendulum of lengths in the ratio 9 : 1 are started at time t = 0. They will again be in phase. After shorter pendulum has made n oscillation, where n is:
Given: The periods of pendulum are in the ratio of 3 : 1. From the relation of time period T∝l Suppose the pendulum be in phase after n. .oscillation of smaller pendulum. Then larger pendulum has made (n−1) oscillation in the same duration it means (n−1)3=n×1 Hence, n=23