Find the equivalent resistance of the network shown in figure between the points A and B.



Case 1: Potential at terminal A > Potential at terminal B
The diode will be forward biased and it can be replaced by short circuit.


Net resistance =
= 10/2 = 5Ω



Case 2: Potential at terminal A < Potential at terminal B
The diode will be reverse biased and it can be replaced by open circuit.


Net resistance=10Ω


1