Question

If a copper rod carries a direct current, the magnetic field associated with the current will be?

• A. Parallel to the rod
• B. Perpendicular to the rod
• C. Circular around the rod
• D. No magnetic field

Hint:

Use the right-hand rule to determine the direction of the magnetic field around current-carrying conductors.

Answer 1

The Correct Option is C

A magnetic field is generated around a straight conductor, like a copper rod, when an electric current passes through it. Ampere’s Circuital Law quantifies this relationship: \[ \oint B \cdot dl = \mu_0 I, \] where \( B \) represents the magnetic field, \( \mu_0 \) is the permeability of free space, and \( I \) is the current in the conductor. The magnetic field lines are concentric circles surrounding the conductor. The direction of the field is determined by the right-hand rule: align your thumb with the current's direction; the direction your fingers curl indicates the magnetic field's direction.