Question

(a) in the circuit shown here, what will happen to the brightness of the lamp l when a solid iron rod is inserted in the air-cored coil c connected in the circuit? (b) an alternating voltage of frequency is applied across a series lcr circuit. Let be the resonance frequency for the circuit. Will the current in the circuit lag, lead or remain in phase with the applied voltage when ()/> <1,7 explain your answer in each case.

Answer 1

A bar magnet M is dropped so that it falls vertically through the coil C. The graph obtained for voltage produced across the coil vs time is shown in figure (b). (i) Explain the shape of the graph. (ii) Why is the negative peak longer than the positive peak?