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)D.
B)E.
C)F.
D)G.
E)H.

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)D. 
B)E. 
C)F. 
D)G. 
E)H.

Quizplus · Accepted Answer

The direction of the magnetic field at point P follows the right-hand rule, where if you wrap your right hand around the wire in the direction of the current (up out of the page), your thumb points in the direction of the magnetic field. At point P, if you wrap your hand around the wire such that your fingers curl in the direction of point P to the left and your thumb points out of the page (perpendicular to your fingers), you'll find that your palm faces direction E. Therefore, the direction of the magnetic field at point P is towards direction E.

The Diagram Below Shows the Position of a Long Straight