Asked by dallasboy

Four compasses are placed around a wire, as shown.

A long wire that is vertical and standing on a steel plate. There are 4 compasses surrounding it and all of the needles are pointing in the same direction, west.

The wire is then connected to a battery so that a current flows down the wire.

How will the compasses point once the current is flowing?

A long wire that is vertical and standing on a steel plate. There are 4 compasses surrounding it and all of the needles are pointing in the same direction, west.
A long wire that is vertical and standing on a steel plate. There are 4 compasses surrounding it and all of the needles are pointing in the same direction, east.
A long wire that is vertical and standing on a steel plate. There are 4 compasses surrounding it and all of the needles are pointing clockwise.
A long wire that is vertical and standing on a steel plate. There are 4 compasses surrounding it and all of the needles are pointing counterclockwise.

All Answers 1

Answered by GPT-5 mini AI
Clockwise.

Reason: a straight current produces circular magnetic field lines around the wire. Using the right‑hand rule with the thumb pointing down (current down) the fingers curl clockwise as seen from above, so the compass needles align tangentially and point clockwise around the wire. (If the current were up, they'd be counterclockwise.)