Question

If resistance R1 is 10KΩ, V2 = 2V, V1 = 3V and the diode is ideal, then the current I through the circuit will be ___________

(a) 0.3mA

(b) 0.6mA

(c) 0.7mA

(d) 0.1mA

The question was posed to me in examination.

Origin of the question is Ideal Diode Model-1 in portion Diode Circuit of Analog Circuits

Answer 1

Correct answer is (d) 0.1mA

The best I can explain: In ideal diode model the diode is considered as a perfect conductor in forward bias and perfect insulator in reverse bias. That is voltage drop at forward bias is zero and current through the diode at reverse bias is zero.

Since the diode is in reverse bias, it can be considered open and no current flows through it. Then effective voltage becomes 3-2 = 1V so current is 1/10K = 0.1mA.