The zener diode has a $\mathrm{V}_{\mathrm{z}}=30 \mathrm{~V}$. The current passing through the diode for the following circuit is ____ mA .

JEE Main · 2021 · 26 Feb 2021 · Shift 2 · Semiconductors

The zener diode has a

V_{z} = 30 V

. The current passing through the diode for the following circuit is ____ mA .

Answer: 9

In breakdown the zener holds

30

V, and the

5 k Ω

load sits across it, so the load draws

i_{L} = \frac{30}{5 \times 1 0 ^{3}} = 6 mA

The rest of the supply,

90 - 30 = 60

V, falls across the

4 k Ω

series resistor, which therefore carries

i_{S} = \frac{60}{4 \times 1 0 ^{3}} = 15 mA

The series current splits between the load and the diode, so the diode takes

15 - 6 = 9

mA.

JEE Main · 2021 · 26 Feb 2021 · Shift 2 · Integer answer