A compass with its needle pointing north sits on a table. We place a straight wire over the compass parallel to its needle. We then send a conventional current running south to north through the wire. How does the compass needle respond to the current?
A) The compass needle deflects toward the west.
B) The compass needle deflects toward the east.
C) The compass needle does not do anything.
D) The compass needle turns around to point south.

Question

Quizplus · Accepted Answer

The current flowing south to north creates a magnetic field around the wire. According to the right-hand rule, this magnetic field circles the wire in a direction that causes the compass needle to deflect toward the west.

A Compass with Its Needle Pointing North Sits on a Table