The current in a coil with a self-inductance of 1.5 mH increases from 0 to 2.0 A in a tenth of a second.What is the induced emf in the coil?
A) 15 mV
B) 0.30 V
C) 0.10 V
D) 30 mV

Question

Quizplus · Accepted Answer

We can use the formula for induced emf in a coil:

emf = -L(dI/dt)

Where L is the self-inductance, I is the current, and dt is the change in time.

Substituting the values, we get:

emf = -(1.5 mH)(2.0 A/0.1 s) = -30 mV

Since the emf is induced in the opposite direction to the change in current, we take the absolute value to get the final answer:

emf = 30 mV, which is option D.

The Current in a Coil with a Self-Inductance of 1