Question

A uniform disc of radius R is pivoted at point O on its circumference. The time period of small oscillations about an axis passing through O and perpendicular to plane of disc will be

• A. T = 2(3R/2g)
• B. T = 2(R/g)
• C. T = 2(2R/g)
• D. T = 2(2R/3g)

Answer 1

The correct option is A T = 2(3R/2g)

The time period of oscillations of a compound pendulum is given by T = 2(I/mgd)

For a disc with its axis passing through its circumference is $l=\frac{m{R}^2}{2}+m{R}^2=\frac{3m{R}^2}{2}$

Substituting the values, we get T = 2(3R/2g)