Electromagnetic...

Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area A = 10 cm² and length = 20 cm. If one of the solenoids has 300 turns and the other 400 turns, their mutual inductance is
(µ₀ = 4 π × 10^–7 TmA^–1)

A uniformly wound solenoid coil of self-inductance 1.8 × 10^–4 H and resistance 6 Ω is broken up into two identical coils. These identical coils are then connected in parallel across a 12 V battery of negligible resistance. The time constant for the current in the circuit is

The mutual inductance between two coils is 1.25 henry. If the current in the primary changes at the rate of 80 ampere/second, then the induced e.m.f. in the secondary is

A coil of wire of a certain radius has 600 turns and a self-inductance of 108 mH. The self-inductance of a 2nd similar coil of 500 turns will be

A closely wound coil of 100 turns and area of cross-section 1 cm² has a coefficient of self-induction 1 mH. The magnetic induction in the centre of the core of the coil when a current of 2A flows in it, will be

Two circuits have coefficient of mutual induction of 0.09 henry. Average e.m.f. induced in the secondary by a change of current from 0 to 20 ampere in 0.006 second in the primary will be

In the following circuit, the bulb will become suddenly bright if

A coil and a bulb are connected in series with a dc source, a soft iron core is then inserted in the coil. Then

Self-induction of a solenoid is

Mutual inductance of two-coils can be increased by