Question 1
A coil with 100 turns is placed in a magnetic field. The magnetic flux through the coil changes from 0 to 5 Wb in 2 seconds. What is the induced EMF in the coil?
A. 250 mV
B. 2.5 V
C. 25 V
D. 250 V
Question 2
According to Lenz's Law, the direction of the induced current in a coil is such that it:
A. Increases the cause producing it.
B. Decreases the cause producing it.
C. Is always clockwise.
D. Is always anti-clockwise.
Question 3
A conductor is moving perpendicular to a magnetic field. If the speed of the conductor is doubled, the induced EMF will:
A. Remain the same.
B. Double.
C. Halve.
D. Quadruple.
Question 4
Eddy currents are:
A. Currents induced in a solid metal block.
B. Currents that flow in a circular path.
C. Currents that flow in a straight line.
D. Direct currents produced by a battery.
Question 5
Which of the following is NOT an application of eddy currents?
A. Induction cooking.
B. Magnetic braking in trains.
C. Electromagnetic shielding.
D. Charging a smartphone.
Question 6
a) Describe Faraday's observations that led to the concept of electromagnetic induction. [3]
b) Define magnetic flux and state its unit. [2]
Question 7
a) State Faraday's law of electromagnetic induction. [3]
b) If the magnetic flux through a coil changes by 0.05 Wb in 0.1 seconds, calculate the induced EMF in the coil. [2]
Question 8
a) Explain Lenz's law and its significance in the context of conservation of energy. [3]
b) A coil is placed near a magnet. If the north pole of the magnet is moved towards the coil, what will be the direction of the induced current in the coil? [2]
Question 9
a) Describe the relationship between magnetic flux linkage and the number of turns in a coil. [2]
b) If a coil with 100 turns experiences a change in magnetic flux of 0.02 Wb in 0.5 seconds, calculate the induced EMF. [3]
c) How would the induced EMF change if the number of turns in the coil were doubled? [2]
Question 10
a) Compare the similarities and differences between gravitational fields and electric fields. [3]
b) Define electric potential and state its unit. [2]
c) How is work done related to a change in electric potential? [3]