Question

The time period of a simple pendulum of infinite length is

(a) infinite

(b) 2π√R/g

(c) 2π√g/R

(d) 1/2π√g/R

Answer 1

Correct Answer is: (b) 2π√R/g

Force towards A = mgsin θ = mg x/R. (A = mean position)

Acceleration towards A = g x/R

or x = - g x/R

For ω² = g/R, x = - ω² x

T = 2π/ω = 2π√R/g.