The diagram below shows the position of a long straight wire perpendicular to the page and a set of directions labeled A through H. When the current in the wire is directed up out of the page,the direction of the magnetic field at point P is
A)A.
B)B.
C)C.
D)D.
E)E.

Question

The diagram below shows the position of a long straight wire perpendicular to the page and a set of directions labeled A through H.  When the current in the wire is directed up out of the page,the direction of the magnetic field at point P is
A)A. 
B)B. 
C)C. 
D)D. 
E)E.

Quizplus · Accepted Answer

The right hand rule tells us that the magnetic field direction curls around the wire in a counterclockwise direction when the current is directed up out of the page. At point P, this means the direction of the magnetic field is perpendicular to both the wire and the plane of the page, pointing to the left. This matches choice C.

The Diagram Below Shows the Position of a Long Straight