Question

A long straight wire of radius R carries a current distributed uniformly over its cross-section. The magnitude of the magnetic field is

• A. maximum at the axis of the wire
• B. minimum at the axis of the wire
• C. maximum at the surface of the wire
• D. minimum at the surface of the wire

Answer 1

Answer: (B), (C)

maximum at the surface of the wire
minimum at the axis of the wire

For a current carrying long straight wire, if the current distributed uniformly over its cross-section then the magnitude of the magnetic field is minimum at the axis of the wire maximum at the surface of the wire.