LR-Circuit Consider the series LR-circuit shown in Fig. 4. 1. l 0, in which a constant input voltage V0 has been supplied until t = 0, when it is shut off.

(a) Before carrying out the mathematical analysis, describe what you think will happen to the circuit.
(b) For t > 0, use Kirchoff's voltage law to determine the sum of the voltage drops around the circuit. Set it equal to zero to obtain a first-order differential equation involving R, i, L, and I. What are the initial conditions?
(c) Solve the DE in (b) for current I. Does your answer agree with (a)? Explain.
(d) Use the values R = 40 ohms, L = 5 henries, and V0 = 10 volts to obtain an explicit solution.

Transcribed Image Text:

R=40ohms @iなfort20 Vo for <0 0 no) = L = 5 henries FIGURE 4.1.10 An LR-circuit (Problem 57)