Question

Find the equivalent resistance of the network in the figure between points A and B (assuming diode is ideal) if:
1. Va>Vb
2. Va<Vb

P.S: Sorry for the horrible drawing​

Answer 1

Answer:

if Va is greater than Vb ,diode is forward biased i.e resistance of diode can be assumed 0.

so net resistance of circuit will be 12×4/ 12+4

ie 48/16=3

now if Vb is greater than Va then diode will act as infinite resistance or open loop so current will pass through upper resistance only.

so net resistance will be 12 ohm