Question

Which of the following describes what occurs to the magnetic field produced by a current carrying wire when there is no electric current flowing through the wire?

A. nothing
B. the magnetic field is stronger
C. there is no magnetic field
D. the magnetic field is weaker

Answer 1

A magnetic field can be generated in one of two ways:
1) By a permanent magnet, like a horseshoe magnet or bar magnet.
2) Any moving charge generates a magnetic field that circulates around the direction of motion.

Which of these fits a wire with no current in it?

P.S. These two ways are actually the same -- in case 1, the moving charges are the electrons in the metal!

Answer 2

So which one?

Answer 3

i think there is no magnetic field surrounding a wire that doesn't carry any current.

Answer 4

@meganjay54: No current in wire = no moving charge = no magnetic field. So it's C.