Question

which of the following is true regarding current in an external circuit?
a) direct current always moves from the positively charged terminal to the negatively charged terminal.
b) alternating current always moves from the positively charged terminal to the negatively charged terminal.
c) the flow of an alternating current switches direction when a generators terminals change its charge.
d) a direct current constantly switches direction of flow to match the change of charge at each terminal.

Explanation:

• Option A: Direct current (DC) is defined as current that flows in a fixed direction, from the positive terminal to the negative terminal of a power source in an external circuit, which is correct.
• Option B: Alternating current (AC) periodically reverses its direction, so it does not always flow from positive to negative.
• Option C: An AC generator's terminals do not "change charge"; AC direction reversal comes from the changing magnetic flux in the generator, not terminal charge shifts.
• Option D: Direct current does not switch direction; it maintains a constant flow direction.

Answer:

A) Direct current always moves from the positively charged terminal to the negatively charged terminal.
C) The flow of an alternating current switches direction when a generator's terminals change its charge.