A rectangular coil, with corners labeled ABCD, has length L and width w. It is placed between the poles of a magnet, as shown in the figure If there is a current I flowing through this coil in the direction shown, what is the direction of the force acting on section AB of this coil?
A) perpendicular to and into the page
B) perpendicular to and out of the page
C) in the direction of the magnetic field
D) in the opposite direction of the magnetic field
E) The force is zero.

Question

A rectangular coil, with corners labeled ABCD, has length L and width w. It is placed between the poles of a magnet, as shown in the figure If there is a current I flowing through this coil in the direction shown, what is the direction of the force acting on section AB of this coil? 
A) perpendicular to and into the page 
B) perpendicular to and out of the page 
C) in the direction of the magnetic field 
D) in the opposite direction of the magnetic field 
E) The force is zero.

Quizplus · Accepted Answer

According to the right-hand rule, the direction of the magnetic force on a current-carrying wire is perpendicular to both the direction of the current and the direction of the magnetic field. In this case, the magnetic field is going into the page, and the current is going up on section AB. Therefore, the force on section AB is perpendicular to the page and into the page, which is choice A.

A Rectangular Coil, with Corners Labeled ABCD, Has Length L