A dipole of dipole moment 'p' is placed in non-uniform electric field along x-axis. Electric field is increasing at the rate of 1 V m^-1 then the force on dipole is

• 0

• 2p

• p/2

• p

Dimensional formula of angular momentum is

• [ M L² T^-1 ]

• [ M² L² T^-2 ]

• [ M L² T^-3 ]

• [ M L T^-1 ]

Relation between magnetic moment and angular velocity is

• M ∝ ω

• M ∝ ω²

• M ∝ $\sqrt{\mathrm{\omega }}$

• None of these

84.

Given that force  $\left( 5\hat{\mathrm{i}} + 7\hat{\mathrm{j}} - 3\hat{\mathrm{k}} \right)$N  acts on a particle at position  $\left( \hat{\mathrm{i}} + \hat{\mathrm{j}} - \hat{\mathrm{k}} \right)$m. Find torque of this force on the particle about origin.

• $4\hat{\mathrm{i}} - 2\hat{\mathrm{j}} + 2\hat{\mathrm{k}}$

• $2\hat{\mathrm{i}} - 3\hat{\mathrm{j}} + 4\hat{\mathrm{k}}$

• $5\hat{\mathrm{i}} - 2\hat{\mathrm{j}} + 3\hat{\mathrm{k}}$

• $6\hat{\mathrm{i}} - 4\hat{\mathrm{j}} + 4\hat{\mathrm{k}}$

Assertion: Moment of inertia is always constant. 

Reason:  Angular moment is conserved that is why moment of inertia is constant.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion:  Centre of mass of a system does not move under the action of internal forces. 

Reason: Internal forces are non conservative forces.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

If 2 kg mass is rotating on a circular path of radius 0.8 m with angular velocity of 44 rad/sec. If radius of the path becomes 1 m, ther what will be the value of angular velocity?

• 28.16 rad/sec

• 19.28 rad/sec

• 8.12 rad/sec

• 35.26 rad/sec

A solid cylinder, a circular disc, a solid sphere and a hollow cylinder of the same radius are placed on an inclined plane. Which of the following will have maximum acceleration at the bottom of the plane?

• Circular disc

• Solid cylinder

• Solid sphere

• Hollow cylinder

Calculate the heat emitted by a bulb of 100 W in 1 min.

• 100 J

• 1000 J

• 600 J

• 6000 J

What is the moment of inertia for a solid sphere w.r.t. a tangent touching to its surface?

• 2/5 MR²

• 7/5 MR²

• 2/3 MR²

• 5/3 MR²