HSC Science Class 12 - Tamil Nadu Board of Secondary Education Question Bank Solutions for Physics

A bar magnet is placed in a uniform magnetic field whose strength is 0.8 T. If the bar magnet is oriented at an angle 30° with the external field experiences a torque of 0.2 Nm. Calculate

1. the magnetic moment of the magnet
2. the work is done by the magnetic field in moving it from the most stable configuration to the most its configuration and also compute the work done by the applied magnetic field in this case.

A non – conducting sphere has a mass of 100 g and radius 20 cm. A flat compact coil of wire with turns 5 is wrapped tightly around it with each turns concentric with the sphere. This sphere is placed on an inclined plane such that plane of coil is parallel to the inclined plane. A uniform magnetic field of 0.5 T exists in the region in a vertically upward direction. Compute the current 1 required to rest the sphere in equilibrium.

Compute the torque experienced by a magnetic needle in a uniform magnetic field.

When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is

A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?

What do you mean by self-induction?

What is meant by mutual induction?

Define self-inductance of a coil interms of

1. magnetic flux and
2. induced emf

How will you define the unit of inductance?

What do you understand by self-inductance of a coil?

Give the physical significance of self-inductance of a coil.

Assuming that the length of the solenoid is large when compared to its diameter, find the equation for its inductance.

An inductor of inductance L carries an electric current i. How much energy is stored while establishing the current in it?

Show that the mutual inductance between a pair of coils is same (M₁₂ = M₂₁).

Determine the self-inductance of 4000 turn air-core solenoid of length 2m and diameter 0.04 m.

Two air core solenoids have the same length of 80 cm and same cross–sectional area 5 cm². Find the mutual inductance between them if the number of turns in the first coil is 1200 turns and that in the second coil is 400 turns.

A long solenoid having 400 turns per cm carries a current 2A. A 100 turn coil of cross-sectional area 4 cm² is placed co-axially inside the solenoid so that the coil is in the field produced by the solenoid. Find the emf induced in the coil if the current through the solenoid reverses its direction in 0.04 sec.

A 200 turn circular coil of radius 2 cm is placed co-axially within a long solenoid of 3 cm radius. If the turn density of the solenoid is 90 turns per cm, then calculate mutual inductance of the coil and the solenoid.

The solenoids S₁ and S₂ are wound on an iron-core of relative permeability 900. The area of their cross-section and their length are the same and are 4 cm² and 0.04 m, respectively. If the number of turns in S₁ is 200 and that in S₂ is 800, calculate the mutual inductance between the coils. The current in solenoid 1 is increased from 2A to 8A in 0.04 second. Calculate the induced emf in solenoid 2.

For light incident from air on a slab of refractive index 2, the maximum possible angle of refraction is ______.