Self Induction

inductor, current Self-induction apparatus is currently missing Updated on 05/30/13

1. To show that as a result of self-induction the growth of current in an inductive circuit is slow. 2. To show that the energy stored in the magnetic field of an inductor appears as a surge of self-induced current when the circuit is broken.

Self-contained self-induction apparatus, 12 V supply

Connect the 12 V supply to the circuit so that the two lamps are supplied in parallel. The left-hand lamp, however, is in series with a low resistance inductor. With switch S2 open and switch S1 closed the left-hand lamp will be seen to light up fractionally behind the right-hand lamp. If S2 is now closed shorting the left-hand lamp out of the circuit then all the energy of the magnetic field of the inductor will be delivered to the right-hand lamp when S1 is opened. Open S1 and the right-hand lamp will be seen to flash momentarily at the break.