If in a simple pendulum experiment the length of the inextensible string is increased by a factor of four, its period is increased by a factor of

A.

4

B.

\(\frac{\pi}{2}\)

C.

\(\frac{1}{4}\)

D.

2\(\pi\)

E.

2

Correct answer is E

In simple pendulum, T = 2\(\pi\)\(\sqrt\frac{L}{g}\)

\(\frac{T_2}{T_1}\) = \(\sqrt\frac{L_1}{L_2}\) but, L2 = 4L1

\(\frac{T_2}{T_1}\) = \(\sqrt\frac{L_1}{4L_1}\)


T2 = 4T1