Which one of the following graph represents forward bias characteristic of a diode?

Step-by-step solution

Conceptual problem. Theory based. Graph D has exponential characteristic, which is similar to ideal diode. The current-voltage function (also called the " i-v characteristic") for an ideal diode is i(v)=I_S [ ( v V_T )-1 ], v>V_Z where I_S is the reverse saturation current, v is the applied voltage (reverse bias is negative), V_T is constant dependent on temperature, and is the emission coefficient, which is 1 for germanium devices and 2 for silicon devices. V_Z is the reverse bias break done voltage.