7.20 The 240 V, 22 source in the circuit in Fig. P7.20 is inadvertently short-circuited at its terminals a, b. At MULTISIM the time the fault occurs, the circuit has been in operation for a long time. PSPICE a) What is the initial value of the current iab in the short-circuit connection between terminals a, b? b) What is the final value of the current lab? c) How many microseconds after the short circuit has occurred is the current in the short equal to 114 A? Figure P7.20 240 V 202 a b 10 (2 2 mH 150 6 mH