An inductor with inductance L and an inductor with inductance 2L connected in parallel. When the rate of change of the current in the larger inductor is 2000 A/s the rate of change of the current in the smaller is:
A) 400 A/s
B) 1200 A/s
C) 1600 A/s
D) 2000 A/s
E) 2400 A/s

Question

Quizplus · Accepted Answer

In parallel, the voltage across inductors is the same. Using V = L(di/dt), the rate of change of current is inversely proportional to inductance. Therefore, (di/dt)_smaller = 2 * (di/dt)_larger = 2 * 2000 A/s = 4000 A/s. However, the question asks for the rate of change of the current in the smaller inductor, which is half of the larger one, so 4000 A/s / 2 = 2000 A/s.

An Inductor with Inductance L and an Inductor with Inductance