Self and Mutual Induction

Author:Embibe Experts
NEET
IMPORTANT

Important Questions on Self and Mutual Induction

EASY
IMPORTANT

A long solenoid has 500 turns. When a current of 2 A is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4×10-3 Wb. The self-inductance of the solenoid is

HARD
IMPORTANT

Two conducting loops of radi R1 and R2 are concentric and are placed in the same plane. If R1>>R2, the mutual inductance M between them will be directly proportional to-

EASY
IMPORTANT

Energy is stored in the choke coil in the form of-

MEDIUM
IMPORTANT

The equivalent inductance of two inductances is 2.4 H when connected in parallel and 10 H when connected in series. The difference between the two inductances is

EASY
IMPORTANT

The mutual inductance of two coils when magnetic flux changes by 2×10-2 Wb and current changes by .01 A is :-

EASY
IMPORTANT

The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance :-

HARD
IMPORTANT

A small square loop of wire of side l is placed inside a large square loop of wire of side LL>>l. The loops are coplanar and their centres coincide. The mutual inductance of the system is proportional to 

EASY
IMPORTANT

The mutual inductance between a primary and secondary circuits is 0.5 H. The resistance of the primary and the secondary circuits are 20 Ω and 5 Ω respectively. To generate a current of 0.4 A in the secondary, current in the primary must be changed at the rate of

MEDIUM
IMPORTANT

The current (I) in the inductor is varying with time according to the plot shown in figure.

Question Image

Which one of the following is the correct variation of voltage with time in the coil ?

 

EASY
IMPORTANT

A current time curve is shown in the following diagram. This type of current is passed in the primary coil of transformer. The nature of induced emf in the secondary coil will be :-
                             Question Image

EASY
IMPORTANT

Two co-axial solenoids shown in figure. If key of primary suddenly opened then direction of instantaneous induced current in resistance ‘R’ which connected in secondary:
Question Image

EASY
IMPORTANT

Pure inductors each of inductance 3 H are connected as shown. The equivalent induction of the circuit is :-

Question Image

MEDIUM
IMPORTANT

Assertion : The coils in the resistance boxes are made by doubling the wire.
Reason : When two coils are wound on each other, the mutual inductance is zero. 

EASY
IMPORTANT

Assertion : Self-inductance is called the inertia of electricity.
Reason : In a LR circuit, the inductor opposes any change in current. 

HARD
IMPORTANT

An inductor (L=100 mH), a resistor (R=100 Ω), and a battery (E=100 V) are initially connected in series as shown in the figure. After a long time, the battery is disconnected after short-circuiting points A and B. The current in the circuit 1 ms after the short circuit is :

Question Image

EASY
IMPORTANT

The bob of a simple pendulum is replaced by a magnet. The oscillation are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is shortcircuited. Then which of the following happens ?

EASY
IMPORTANT

 In R-L circuit R=4 Ω, L=0.5 H, emf of cell, ε=6 V. Work done in changing current from 0.80 A to 0.81 A is:- 

MEDIUM
IMPORTANT

Find self inductance (in henry) of a solenoid of length 20 m, total turns 104 and area 1 cm2 which is filled with a medium of relative permeability, μr=5000.

MEDIUM
IMPORTANT

A wire has length 1 m, radius 2 mm and μr=20000. Find its self-inductance.