The switch in the figure is closed at t = 0 when the current I is zero.When I = 15 mA,what is the potential difference across the inductor?

Question

Quizplus · Accepted Answer

At t=0, the current through the inductor is zero, and due to its property, it will resist any change in current. So, when the switch is closed, the inductor initially resists the sudden increase in current, and the potential difference across it can be given by:
VL = L(dI/dt), where L is the inductance of the inductor.
Let's assume that the switch is closed for a sufficiently long time such that the current becomes constant. When the current becomes constant at 15 mA, the rate of change of current becomes zero, and hence, the potential difference across the inductor becomes zero (VL = L(dI/dt) = L*0 = 0). So, the potential difference across the inductor when the current is 15 mA is zero. Therefore, the correct answer is D.

The Switch in the Figure Is Closed at T =