Problems Through deal with the RL circuit of Fig., a series circuit containing an inductor...

Problems Through deal with the RL circuit of Fig., a series circuit containing an inductor with an inductance of L henries, a resistor with a resistance of R ohms, and a source of electromotive force (emf), but no capacitor. In this case Eq. reduces to the linear first-order equationLI′ + RI = E(t).

In the circuit of Fig., suppose that L = 5H, R = 25 Ω, and the source E of cmf is a battery supplying 100 V to the circuit. Suppose also that the switch has been in position 1 for a long time, so that a steady current of 4 A is flowing in the circuit. At time t = 0, the switch is thrown to position 2, so that I(0) = 4 and E = 0 for t ≥ 0. Find