Define the term magnetic flux.
State Faraday’s law for electromagnetic induction.
As shown in Fig. 10.1, a solenoid has a coil C of wire wound closely around its centre. Coil C has 96 turns. The uniform magnetic flux $\Phi$ (in weber) in the solenoid is given by $\Phi = 6.8 \times 10^{-6} \times I$, where $I$ is the current (in amperes) in the solenoid.
As shown in Fig. 10.1, a solenoid has a coil C of wire wound closely around its centre. Coil C has 96 turns. The uniform magnetic flux $\Phi$ (in weber) in the solenoid is given by $\Phi = 6.8 \times 10^{-6} \times I$, 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 $3.5\,\text{A}$ is reversed in the solenoid in a time of $2.4\,\text{ms}$.
The d.c. supply in Fig. 10.1 is now replaced by a sinusoidal alternating supply. Describe qualitatively the e.m.f. now induced in coil C.