Question

4.2.2 quiz: electromagnetism
question 4 of 10
how does the electric current of an ac generator differ from that of a dc generator?
a. it flows through the permanent magnets.
b. it is much weaker.
c. it is much stronger.
d. it constantly reverses direction.

Explanation:

AC stands for alternating current. The key characteristic of alternating current is that its direction changes periodically. In an AC generator, the current constantly reverses direction. DC (direct current) has a constant direction. Option A is incorrect as current in generators (both AC and DC) doesn't flow through permanent magnets in a way that differentiates them like this. Options B and C are wrong because the strength of current (AC or DC) depends on various factors like the generator's design, power input etc., and it's not a fundamental difference between AC and DC generators in terms of current direction which is what the question is about.

Answer:

D. It constantly reverses direction.