Question

From the zener diode circuit shown in figure, the current through the zener diode is.

• A. 34 mA
• B. $31.5mA$
• C. $36.5mA$
• D. $2.5mA$

Answer 1

Answer: (B)

$31.5mA$

Answer 2

: here , $R_{L} = 5 \times 10^{3}\Omega,V_{i} = 220V$

Zener voltage, $V_{Z} = 50V$

Load current,

$I_{L} = \frac{V_{Z}}{R_{L}} = \frac{50}{20 \times 10^{3}} = 2.5 \times 10^{- 3}A$

Current through R,

$I = \frac{220 - 50}{5 \times 10^{3}} = 34 \times 10^{- 3}A$

Zener current

}{= 34 \times 10^{- 3} - 2.5 \times 10^{- 3} }{= 31.5 \times 10^{- 3}A = 31.5mA}$$