Question

A wire is lying horizontally in the north-south direction and there is a horizontal magnetic field pointing towards the east. Some positive charges in the wire move north and an equal number of negative charges move south. The direction of the force on the wire will be?

• A. East
• B. Down, into the page
• C. Up, out of the page
• D. West

Answer 1

The correct option is B Down, into the page

The direction of the force experienced by the wire can be determined using the Fleming’s left hand rule. The forefinger points to the direction of the magnetic field. The middle finger points in the direction of the current. The thumb gives the direction of force or motion acting on the conductor.

The direction of current is in the direction of the motion of positive charges. Hence, the direction of force is into the page and downwards.

Hence, option B is the correct answer.