Question

The time period of a simple pendulum on the surface of the earth is 4s. Its time period on the surface of the moon is

• A. 4 s
• B. 8 s
• C. 10 s
• D. 12 s

Answer 1

Answer: (C)

10 s

Answer 2

Acceleration due to gravity on the surface of the moon is $\frac { 1 } { 6 }$ that of surface of the earth.

….. (i)

On earth

On moon $\mathrm { T } _ { \mathrm { m } } = 2 \pi \sqrt { \frac { \mathrm {~L} } { \mathrm {~g} _ { \mathrm { m } } } }$

$\therefore \frac { T _ { m } } { T _ { e } } = \sqrt { \frac { g _ { e } } { g _ { m } } } = \sqrt { 6 }$ (Using (i))