QJEEM21Phf147: JEE Main 2021 Physics - Class 12 JEEM21Phf147 Solution: For the circuit shown below, calculate the value of I z :

Consider the given figure and draw the direction of current as follows


Here, current I is flowing through resistance R_s and I₁ is the current flowing through R = 2000 $\Omega$

$\therefore$ Current, $I = {{{V_i} - {V_z}} \over {{R_s}}} \Rightarrow I = {{100 - 50} \over {1000}}$

= 50 mA .... (i)

[ $\because$ Resistance and Zener diode are in parallel, therefore voltages across them are same]

and current, ${I_1} = {{50} \over {2000}} = 25$ mA .... (ii)

By using Kirchhoff's current law,

$\because$ I = I₁ + I_z

$\Rightarrow$ I_z = I $-$ I₁ ..... (iii)

From Eq. (i) and (ii) and, we get

$\Rightarrow$ I_z = (50 $-$ 25) mA

I_z = 25 mA