3.5 Design a 7.5-V zener regulator circuit using a 7.5-V zener specified at 10 mA. The zener has an

incremental resistance r₂ = 30 22 and a knee current of 0.5 mA. The regulator operates from a 10-V

supply and has a 1.5-k2 load.

a) What is the value of R you have chosen?

b) What is the regulator output voltage when the supply is 10% high and 10% low?

c) What is the output voltage when the supply is 10% high and the load is removed?

d) What is the smallest possible load resistor that can be used while the zener operates at a current

no lower than the knee current while the supply is 10% low? What is the load voltage in this case?