A zener diode of voltage `V_(Z)(=6` volt) is used to maintain a constant voltage across a load resistance `R_(L)(=1000Omega)` by using a series resistance `R_(S)(+100Omega)`. If the emf or source is `E(=9V)`, calculate the value of current through series resistance, zener diode and load resistance. What is the power being dissipated in zener diode.

Explanation

Here, `E=9V,V_(z)=6V,R_(L)=1000 Omega and R_(S)=100 Omega`
Potential drop across series resistor `V_(R)=E-V_(Z)=9-6=3V`
Current through series resistance `R_(S) I=(V_(R))/(R)=(3)/(100)=0.03A`
Current through load resistance `R_(L)I_(L)=(V_(2))/(R_(L))=(6)/(1000)=0.006A`
Current through Zener diode `I_(Z)=I-I_(L)=0.03-0.006=0.024 "amp"`
Power dissipated in zener diode `P_(Z)=V_(2)I_(2)=6xx0.024=0.144 "Watt"`.