A Zener shunt regulator employs a 9.1 V-Zener diode for which V = 9.1 V at lz = 9 mA, with rz = 30 Q. The available supply voltage is 15 V with 10% of voltage variation. (30 points) a) Design the regulator. b) For this diode, what is the value of Vzo? c) For a nominal load resistance R of 1 k and a nominal Zener current of 10 mA, what current (1) must flow in the supply resistor R. d) Find the value of R, specified to one digit, to provide at least the current found in part c) and deduce the nominal output voltage. e) For a 10% change in the supply voltage, what variation in output voltage results?