Question

A Zener diode having break-down voltage $5.6V$ is connected in reverse bias with a battery of emf $10V$ and a resistance of $100\Omega$ in series. The current flowing through the Zener is

• A. $88mA$
• B. $4.4mA$
• C. $0.88mA$
• D. $44mA$

Answer 1

Answer: (D)

A Zener diode offers infinite resistance as long as the reverse voltage across it is less than the break-down value. As soon as the reverse bias voltage cross the break-down level, the residue voltage remains in the circuit with the diode offering zero resistance to it.

Hence here the voltage remaining across the Zener=$10V-5.6V=4.4V$

Therefore the current in the circuit is $\frac{4.4V}{100\Omega }$

$=44mA$