Question

In the illustration, you are looking down on an infinitely long wire with current toward the top of the screen. What direction is the magnetic field caused by the wire at point $P$?

• A. Into the screen.
• B. To the right of the screen.
• C. Out of the screen.
• D. To the left of the screen.

Answer 1

Answer: (C)

Out of the screen.

Using right hand thumb rule, the direction of magnetic field lines due a straight wire is shown in the figure.

Thus the magnetic field at point P points out of the screen.