List of top Physics Questions on Rotational Mechanics asked in MHT CET

A solid sphere rolls down from the top of an inclined plane. On reaching the bottom of the plane, its velocity is '\(V_1\)'. When the same sphere slides down from the top of the same plane of same height, its velocity on reaching the bottom is '\(V_2\)'. The ratio \(V_1:V_2\) is (neglect friction)
Two bodies A and B have moment of inertia \(I_A\) and \(I_B\), and angular momenta \(L_A\) and \(L_B\) respectively. Both of them have same kinetic energy of rotation. So the ratio \(L_A\) to \(L_B\) is
If the earth suddenly contracts to \((\frac{1}{3})^{rd}\) of its present size without change in its mass, the ratio kinetic energy of the earth after and before contraction will be (Earth is assumed to be a rotating sphere about itself)
Using Bohr's quantisation condition, what is the rotational energy in the second orbit for a diatomic molecule? ($I$ = moment of inertia and $h$ = Planck's constant) ______.
A thin uniform rod of length 'L' and mass 'M' is swinging freely about a horizontal axis passing through its end. Its maximum angular speed is '$\omega$'. Its centre of mass rises to a maximum height of ______.
A body is rotating about its own axis. Its rotational kinetic energy is \( x \) and its angular momentum is \( y \). Hence its moment of inertia about its own axis is
Using Bohr's quantization condition, the rotational kinetic energy in the third orbit for a diatomic molecule is \( \left( h = \text{Planck's constant}, I = \text{moment of inertia of diatomic molecule} \right) \)
The moment of inertia of a ring about an axis passing through its centre and perpendicular to its plane is \( I \). It is rotating with angular velocity \( \omega \). Another identical ring is gently placed on it so that their centres coincide. If both the rings are rotating about the same axis, then loss in kinetic energy is
A solid sphere at rest rolls down an inclined plane of vertical height h without sliding. Its speed on reaching the bottom of plane is ($g=$ acceleration due to gravity)
A coil of n turns and resistance $R \Omega$ is connected in series with resistance $R/4$. The combination is moved for time t second through magnetic flux $\phi_1$ to $\phi_2$. The induced current in the circuit is
In hydrogen atom, transition from the state \( n = 6 \) to \( n = 1 \) results in ultraviolet radiation. Infrared radiation will be obtained in the transition
A particle is displaced from point \( P(3 \text{ m}, 4 \text{ m}, 5 \text{ m}) \) to a point \( Q(2 \text{ m}, 3 \text{ m}, 4 \text{ m}) \) under a constant force \( \vec{F} = (3\hat{i} + 4\hat{j} + 5\hat{k})\text{N} \). The work done by the force in this process is
For a thin prism, \(\delta_1\) is the angle of deviation produced, when prism is placed in air. When the prism is immersed in water, the angle of deviation produced is \(\delta_2\). Given \({}_{\text{a}}\mu_{\text{g}} = \frac{3}{2}\) and \({}_{\text{a}}\mu_{\text{w}} = \frac{4}{3}\) . The ratio \(\delta_2 : \delta_1\) is
Two rods of different materials have lengths '\(l_1\)' and '\(l_2\)' whose coefficient of linear expansions are '\(\alpha_1\)' and '\(\alpha_2\)' respectively. If the difference between the two lengths is independent of temperature then
The time period of a simple pendulum inside a stationary lift is \(\sqrt{3}\) second. When the lift moves upwards with an acceleration \(g/3\), the time period will be ( \(g =\) acceleration due to gravity)
A solid sphere of mass ' $m$ ' and radius ' $R$ ' is rotating about its diameter. A solid cylinder of the same mass and same radius is also rotating about its geometrical axis with angular speed twice that of sphere. The ratio of kinetic energy of sphere to kinetic energy of cylinder will be
The magnitude of gravitational potential energy of a body at a distance ' \( R \) ' from the centre of the earth is ' \( E \) '. Its weight at a distance ' \( 1.5 R \) ' from the centre of the earth is
A thin metal wire of length ' L ' and mass ' M ' is bent to form semicircular ring as shown. The moment of inertia about XX' is
The percentage error in the measurement of mass and speed of a particular body is 3% and 4% respectively. The percentage error in the measurement of kinetic energy is
A thin rod of length ' $4L$ ' and mass ' $4m$ ' is bent as shown. Find the moment of inertia about an axis through $O$ and perpendicular to the plane.
The moment of inertia of a body about a given axis is \( 1.2 \, \text{kg m}^2 \). Initially the body is at rest. In order to produce rotational kinetic energy of \( 1500 \, \text{J} \), an angular acceleration of \( 25 \, \text{rad/s}^2 \) must be applied about an axis for a time duration of
The moment of inertia of a circular disc of radius 2 m and mass 1 kg about an axis XY passing through its centre of mass and perpendicular to the plane of the disc is 2 kg m\(^2\). The moment of inertia about an axis parallel to the axis XY and passing through the edge of the disc is
A thin rod of length ' $4L$ ' and mass ' $4m$ ' is bent as shown. Find the moment of inertia about an axis through $O$ and perpendicular to the plane.