2002 AIPMT Semiconductor Electronics: Materials, Devices and Simple CircuitsDiode in Forward and Reverse Bias Medium Question 100 of 106 in Semiconductor Electronics: Materials, Devices and Simple Circuits

For the given circuit of P-N junction diode which is correct : -

For the given circuit of P-N junction diode which is correct : -
A In F.B. the voltage across R is V
B In R.B. the voltage across R is V
C In F.B. the voltage across R is 2V
D In R.B. the voltage across R is 2V

The answer is A.

Solution

Treat the diode as ideal.
In forward bias, an ideal diode has zero resistance (like a closed switch), so there is no voltage drop across it. The whole supply voltage V appears across R.
In reverse bias, an ideal diode has infinite resistance (like an open switch), so no current flows. The voltage across R is zero and the whole V appears across the diode.
The voltage across R can never exceed the supply voltage V.
So in forward bias the voltage across R is V.

Concept Ideal diode as switch

Semiconductor Electronics: Materials, Devices and Simple Circuits in past papers

106 questions from this chapter have appeared across 24 exam years.