Answer to Question #3752 in Mechanics | Relativity for Mia

Question

A long, straight, current-carrying wire runs from north to south.
a. A compass needle placed above the wire points with its north pole toward the east. In
what direction is the current flowing?
b. If a compass is put underneath the wire, in which direction will the needle point?

Answer 1

a. If the needle is oriented to the East, using the right-hand rule, we can conclude that current flows from the south to the north.
b. If the current flows from the South to the North, the needle would be oriented oppositely to previous position - to the West.
If& the current is forwarded to the South, the needle is to the East.