Observation

       The expected answers were;

• Faraday’s law of electromagnetic induction states that whenever there is relative motion between a conductor and magnetic flux, an emf is induced in the conductor, the magnitude of which is proportional to the rate of change.                                         

      (b)  Factors that affect mutual inductance
(i)         Number of turns in each coil
(ii)        Distance between the two coils
(iii)       Permeability of the cores / core material
(iv)       Amount of current in the coils
(v)        Cross-sectional area of the conductor used.

• Devices that use principle of electromagnetic induction

• Electric bell
• Security alarm
• Solenoid
• Loudspeaker / headphone
• Buzzer
• moving coil instrument
• circuit breaker
• transformer
• electric machine
• electric fan
• relays                                                        

Many of the candidates that attempted this question did fairly well.