✓ ASSESSMENT PROBLEM Objective 2-Be able to determine the step response of both RL and RC circuits 7.6 a) Find the expression for the voltage across the 160 kn resistor in the circuit shown in Fig. 7.22. Let this voltage be denoted VA, and assume that the reference polarity for the voltage is positive at the upper terminal of the 160 ks resistor. NOTE: Also try Chapter Problems 7.51 and 7.53. b) Specify the interval of time for which the expression obtained in (a) is valid. Answer: (a)-60 +72e-10 V; (b) r≥ 0. 20 kn w 40 V 60 k 0.25 μF2 28kn 40 kn Figure 7.22 The circuit for Example 7.6. 160 kn 75 V