(a) In the circuit shown in Figure P7.2.20, the zener diode (with zero zener resistance) operates in its reverse breakdown region while the voltage across it is held constant at VZ and the load current is held constant at VZ/RL, as the source voltage varies within the limits VS,min S S,max. Find Imax and Imin for the corresponding Rmin and Rmax, respectively.
(b) Assuming RS = 0 and the source voltage to vary between 120 and 75 V, for a load resistance of 1000 Ω, determine the maximum value of the regulator resistor R if it is desired to maintain the load voltage at 60 V. Also find the required power rating of the zener.
