Question

in a zener diode (dc voltage regulator) circuit with `V_("zener")=7.0` V is used for regulation. Thhe load current is to be 4.0 mA and te unregulated input is 11.0 V. what should be te value of series resistor `R_(s)` if zener diode current is five times te load current
A. `120Omega`
B. `167Omega`
C. `180Omega`
D. `200Omega`

Answer 1

Correct Answer - B
`i_("zener")=5i_(load)=20mA&i_(RS)=i_("zener")+i_(Load)=24mA`
`V_(Rs)+V_("zener")=11`
`V_(RS)+7=11` ,brgt `V_(RS)=4V`
`thereforeR_(S)=(V_(Rs))/(i_(Rs))=(4)/(24xx10^(-3))Omega=167Omega`