(a) (i) Define magnetic flux. (ii) State Faraday's law of electromagnetic induction. (b) A solenoid has a coil C of wire wound tightly about its centre, as shown in [Figure 10.1]. The coil C has 96 turns. The uniform magnetic flux Φ (in weber) in the solenoid is given by the expression Φ = 6.8 × 10⁻⁶ × I where I is the current (in amperes) in the solenoid. Calculate the average electromotive force (e.m.f.) induced in coil C when a current of 3.5 A is reversed in the solenoid in a time of 2.4 ms. e.m.f. = .............................................................. V (c) The d.c. supply in [Figure 10.1] is now replaced with a sinusoidal alternating supply. Describe qualitatively the e.m.f. that is now induced in coil C.

1. (a)(i)Define magnetic flux.[2]
2. (a)(ii)State Faraday's law of electromagnetic induction.[2]
3. (b)Calculate the average electromotive force (e.m.f.) induced in coil C when a current of 3.5 A is reversed in the solenoid in a time of 2.4 ms. e.m.f. = .............................................................. V[2]
4. (c)The d.c. supply in Fig. 10.1 is now replaced with a sinusoidal alternating supply. Describe qualitatively the e.m.f. that is now induced in coil C.[2]

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