Types Of Questions
4 min read

Electromagnetic Induction

- Wondering what kind of questions that can be asked in next exam? Here you go!
1
Very Short Answer Type Questions 1mark
The magnetic flux through a circuit of resistance R changes by an amount in time t. Then the total quantity of electric charges Q that passes any point in the circuit during the timet is represented by:- 
A
B
C
D
Consider the situation as shown in the figure. If the current in long straight conducting wire XY is increased at a steady rate then the induced e.m.f.'s in loops A and B will be
A
clockwise in A, anti clockwise in B
B
anti clockwise in A, clockwise in B
C
clockwise in both A and B
D
anti clockwise in both A and B
A square coil ABCD is lying in xy plane with its centre at origin. A lng straight
wire passing through origin carries a current i = 2t in negative z-direction. The
induced current in the coil is 
A
clockwise
B
anticlockwise
C
alternating
D
zero
2
Short Answer Type Questions -I 2marks
Current is induced when the armature of a generator rotates. Slip rings and brushes are the ways and means by which this current is brought to the outer circuit. Is the arrangement necessary if the magnet in generator is made to rotate ?
An average emf of is induced in an inductor when the current in it is changed from in one direction to the same value in the opposite direction in . Find the self-inductance of the inductor.
Answer in brief:
What are eddy currents? State applications of eddy currents.
3
Short Answer Type Questions - II 3marks
Derive an expression for the total magnetic energy stored in two coils with inductance and and mutual inductance ,when the currents in the coils are and respectively.
Figure shows two long coaxial solenoids, each of length . The outer solenoid has an area of cross-section and number of turns/length . The corresponding values for the inner solenoid are and Write the expression for self-inductance of the two coils and their mutual inductance . Hence show that .
A triangular wire frame (each side = 2m) is placed in a region of time variant magnetic field having dB/dt= T/s. The magnetic field is perpendicular to the plane of the triangle. The base of the triangle AB has a resistance 1 while the other two sides have resistance 2 each. The magnitude of potential difference between the points A and B is . Find .
4
Long Answer Questions 5 marks
A rectangular frame of wire has dimensions and a total resistance of . It is pulled out of a magnetic field by applying a force of (figure). It is found that the frame moves with constant speed.
Find (a) this constant speed, (b) the emf induced in the loop, (c) the potential difference between the points and and (d) the potential difference between the points and .
Consider the situation shown in figure. The wires and are made to slide on the rails with the same speed . Find the electric current in the resistor if (a) both the wires move towards right and (b) if moves towards left but moves towards right