Question

For an ideal junction diode,
a) Forward bias resistance is infinity.
b) Forward bias resistance is zero.
c) Reverse bias resistance is infinity.
d) Both b) and c).​

Answer 1

For an ideal junction, the given options are correct

Forward bias resistance is zero, and Reverse bias resistance is infinity.

Option(D) Both b) and c) is correct.

• An ideal junction diode is the one that acts as a perfect conductor in forwarding bias and acts as a perfect insulator when in reverse bias.
• Now for a perfect conductor, the resistance should be zero.
• And for the perfect insulator, the resistance should be infinity so that no current can flow through it.
• So for an ideal junction diode in the forward bias, the resistance must be zero and for the reverse bias, the resistance should be infinity.

Answer 2

For an ideal junction diode, Forward bias resistance is zero and reverse bias resistance is infinity so option(D) is the correct answer.

• The ideal diode possesses zero resistance for the forward bias, and infinite resistance for the reverse voltage polarity; if attached in an alternating current circuit, the semiconductor diode behaves as an electrical rectifier.
• When the diode is forward biased it is identical to a closed switch in series with a minor equivalent voltage reference proportional to the barrier potential (0.6 V for Silicon) with the positive side towards the anode.