Diode is linear or nonlinear? - Answers

Its a Non Linear Device.Its just an electronic switch which turns on during forward bias and off during reverese bias.That is, it gets shorted with minimum resistance and opened with infinite resistance during forward and reverse biases respectively. More over any linear device has to obey superposition therem and homogenity. A linear device is that whose output is directly propostional to input. In case of diode, output (i.e current) is not directly propostional to it input(i.e voltage across it).From it governing equation I=I' * e^(V/V') ,where I' and V' is constant ,it is absolutly clear.