A circular disc of mass 10 kg is suspended by a wire attached to its centre. The wire is twisted by rotating the disc and released. The period of torsional oscillations is found to be 1.5 sec. The radius of the disc is 15 cm. The torsional spring constant of the wire is:
1. 2.1 Nm rad⁻¹
2. 0.6 Nm rad⁻¹
3. 3.2 Nm rad⁻¹
4. 1.9 Nm rad⁻¹

A body describes simple harmonic motion with an amplitude of 5 cm and a period of 0.2 sec. What is the acceleration of the body when the displacement is 5 cm?
1. −3π² ms⁻²
2. 5π² ms⁻²
3. −5π² ms⁻²
4. 3π² ms⁻²

A body describes simple harmonic motion with an amplitude of \(5~\text{cm}\) and a period of \(0.2~\text{s}\). What is the velocity of the body when the displacement is \(3~\text{cm}\)?
1. \(0.4\pi ~\text{m/s}\)
2. \(0\)
3. \(0.5\pi ~\text{m/s}\)
4. \(0.3\pi ~\text{m/s}\)

A mass attached to a spring is free to oscillate, with angular velocity \(\omega\), in a horizontal plane without friction or damping. It is pulled to a distance${}_{}$ \(x_0\) and pushed towards the centre with a velocity \(v_0\) at time \(t=0\). The amplitude of the resulting oscillations is:
1. \(\sqrt{\left(2x_0^2+\frac{v_0^2}{\omega^2}\right)} \)
2. \(\sqrt{\left(x_0^2+\frac{v_0^2}{\omega^2}\right)} \)
3. \(\sqrt{\left(x_0^2+\frac{v_0^2}{2\omega^2}\right)} \)
4. \(\sqrt{\left( x_0^2+\frac{v_0^2}{\pi\omega^2}\right)} \)

Identify the correct definition:

The displacement of a particle executing S.H.M. is given by x = 0.01sin100$\pi$(t + 0.05). The time period is:

(1) 0.01 s

(2) 0.02 s

(3) 0.1 s

(4) 0.2 s

A boy is swinging in a swing. If he stands, the time period will:

(1) First decrease, then increase

(2) Decrease

(3) Increase

(4) Remain same

The time period of a simple pendulum in a freely falling lift will be:

(1) Finite

(2) Infinite

(3) Zero

(4) All of these

If the effective length of a simple pendulum is equal to the radius of the earth (R), the time period will be:

(1) $T=\pi \sqrt{\frac{R}{g}}$

(2) $T=2\pi \sqrt{\frac{2R}{g}}$

(3) $T=2\pi \sqrt{\frac{R}{g}}$

(4) $T=2\pi \sqrt{\frac{R}{2g}}$

A body executing S.H.M. along a straight line has a velocity of 3 ms^-1 when it is at a distance of 4 m from its mean position and 4 ms^-1 when it is at a distance of 3 m from its mean position. Its angular frequency and amplitude are:

(1) 2 rad s^-1 & 5 m

(2) 1 rad s^-1 & 10 m

(3) 2 rad s^-1 & 10 m

(4) 1 rad s^-1 & 5 m