Question

The time period of a simple pendulum at the centre of the earth is

• A. zero
• B. infinite
• C. less than zero
• D. none of these

Answer 1

Answer: (B)

infinite

Answer 2

Acceleration due to gravity at the center of the earth is zero. $\Longrightarrow g =0$ Time period of a simple pendulum is given by, $T =2 \pi \sqrt{\frac{1}{ g }}$ $\Longrightarrow T =2 \pi \sqrt{\frac{1}{0}} \\\ \therefore T =\infty$ So time period at the centre of the earth becomes infinite.