Question

Referring to the zener diode circuit shown in figure, if $E =15\, V , V _{ z }=9\, V$ and $R _{ L }=3.6\, k \Omega$, then the power dissipated in $R _{ L }$ is_______ $mW$.

Answer 1

Current through $R _{ L }$,
$I _{ L }=\frac{ V _{ z }}{ R _{ L }}=\frac{9}{3.6 \times 10^{3}}$
$=2.5 \times 10^{-3} A$
$\therefore $ Power dissipated in $R _{ L }$
$P _{ L }= V _{ z } I _{ L }=9 \times 2.5 \times 10^{-3}$
$=22.5 \times 10^{-3} W$
$\therefore P _{ L }=22.5\, mW$