Question

$T$ is the time period of simple pendulum on the earth's surface Its time period becomes $x T$ when taken to a height $R$ (equal to earth's radius) above the earth's surface Then, the value of $x$ will be:

• A. $\frac{1}{4}$
• B. 4
• C. $\frac{1}{2}$
• D. 2

Answer 1

Answer: (D)

2

Answer 2

At surface of earth time period
T=2πgℓ​​
At height h=R
g′=(1+Rh​)2g​=4g​
∴xT=2π(g/4)ℓ​​
⇒xT=2×2πgℓ​​
⇒xT=2T⇒x=2