Question

A simple pendulum is executing S.H.M. with a time period T. if the length of the pendulum is increased by 21% the percentage increase in the time period of the pendulum is

• A. 10%
• B. 21%
• C. 30%
• D. 50%

Answer 1

Answer: (A)

10%

Answer 2

As $T \propto \sqrt { l }$ ∴ $\frac { T _ { 2 } } { T _ { 1 } } = \sqrt { \frac { l _ { 2 } } { l _ { 1 } } } = \sqrt { 1.21 }$

⇒ $T _ { 2 } = 1.1 T = T + 10 \% T$ .