The current flowing through an inductor of self-inductance ' L ' is continuously increasing at constant rate. The variation of induced e.m.f. (e) versus dI / dt is shown graphically by graph

Step-by-step solution

The induced electromotive force in an inductor of self-inductance L is given by e = -L dI dt , where e represents the induced e.m.f. and dI dt is the rate of change of current. This relationship shows that e is proportional to dI dt and that the negative sign indicates opposition to current change according to Lenz's law. Graph (A) shows e as constant, which contradicts the dependence on dI dt . Graph (B) shows a straight line through the origin. Given its positive direction downward, e_ down = k dI dt where k > 0