Suppose an emf is induced in a loop of wire by rotating the loop in a magnetic field. If the diameter of the loop were twice as large, how would the induced emf compare?
A) The induced emf would be 4 times as much.
B) The induced emf would be twice as much.
C) There would be no change in the induced emf.
D) The induced emf would be 6.28 times as much.

Question

Quizplus · Accepted Answer

The induced emf in a loop of wire is proportional to the area of the loop. If the diameter of the loop is doubled, the area becomes four times as large (since area is proportional to the square of the diameter), thus the induced emf would be four times as much.

Suppose an Emf Is Induced in a Loop of Wire