Question

A portion of a conducting wire, say length l, is kept for observation in a magnetic field as shown in the figure. The direction in which the conducting wire experiences a force is best described by

• A. South
• B. North
• C. East
• D. West

Answer 1

The correct option is D

West

Force on a current carrying conductor in any external magnetic field is given by

F = il x B, where i is current passing through wire, B is the magnetic field and F is the force, so since the current is flowing in the north direction and magnetic field is pointing into the paper, by taking the cross product the direction of force would be in a plane perpendicular to the plane formed by direction of Magnetic field and current, and it would be westwards. This can also be proved by applying the right hand thumb rule.