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Physics · UNITS AND MEASUREMENT
हिन्दीA simple pendulum has a bob of mass \( m \) attached to a string of length \( l \), oscillating under acceleration due to gravity \( g \). Its time period is given by \( T = 2\pi \sqrt{\frac{l}{g}} \). If the length of the pendulum is increased by \( 21\% \) while keeping mass \( m \) and acceleration due to gravity \( g \) unchanged, the percentage increase in its time period \( T \) will be:
Correct answer · Option 1
10%
Explanation
Since \( T \propto \sqrt{l} \), when length becomes \( 1.21 l_1 \), the new time period is \( T_2 = \sqrt{1.21} T_1 = 1.1 T_1 \). The percentage increase is \( (1.1 - 1) \times 100\% = 10\% \).
