SCERT Maharashtra solutions for Physics [English] 12 Standard HSC chapter 12 - Electromagnetic Induction [Latest edition]

In which of the following devices, the eddy current is not used ______ 

An ideal transformer has 100 turns in the primary and 250 turns in the secondary. The peak value of the AC is 28 V. The rms secondary voltage is nearest to ______ 

The role of inductance is equivalent to ______ 

The energy stored in a 50 mH inductor carrying a current of 4 A is ______ 

In the expression e = –dΦ/dt, the -ve sign signifies ______ 

Two pure inductors each of self-inductance L are connected in series, the net inductance is ______  

A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced e.m.f. is ______ 

State Faraday's laws of electromagnetic induction.

State the mathematical relation between a number of turns in the primary coil to a secondary coil in the step-up transformer. 

State the condition at which we say the two coils kept close to each other are perfectly coupled with each other. 

State Lenz's Law.

A pair of the adjacent coil has a mutual inductance of 1.5 H. If the current in one coil varies from 0 to 20 A in 0.5 s, what is the change of flux linked with the other coil. 

An aircraft of wing span of 50 m flies horizontally in the Earth's magnetic field of 6 x 10^-5 T at a speed of 400 m/s. Calculate the emf generated between the tips of the wings of the aircraft.

A coil of self-inductance 3 H carries a steady current of 2 A. What is the energy stored in the magnetic field of the coil? 

Why and where are eddy currents are undesirable? How are they minimized? 

Define self-inductance.

Define Mutual Inductance.

Explain why the inductance of two coils connected in parallel is less than the inductance of either coil.

An emf of 96.0 mV is induced in the windings of a coil when the current in a nearby coil is increasing at the rate of 1.20 A/s. What is the mutual inductance (M) of the two coils?

Calculate the induced emf between the ends of an axle of a railway carriage 1.75 m long traveling on level ground with a uniform velocity of 50 kmph. The vertical component of Earth's magnetic field (B_v) is 5 × 10^-5 T. 

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + 2, Φ is in milliweber and t is in second. What is the magnitude of the induced emf in the loop at t = 2 seconds?  

Distinguish between Step up and Step Down Transformer.

What is Transformer?

Explain step up and step down transformer?

Determine the motional emf induced in a straight conductor moving in a uniform magnetic field with constant velocity on the basis of Lorentz force.

The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.

The primary and secondary coils of a transformer each have an inductance of 200 x 10^-6 H. The mutual inductance between the windings is 4 x 10^-6 H. What percentage of the flux from one coil reaches the other?

Obtain an expression for the self-inductance of a solenoid.

A plane of a coil of 10 turns is tightly wound around a solenoid of diameter 2 cm having 400 turns per centimeter. The relative permeability of the core is 800. Calculate the inductance of the solenoid. 

Find an expression for the power expended in pulling a conducting loop out of a magnetic field.

Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire. 

Describe the construction and working of a transformer with a neat labelled diagram.