Question

A negatively charged particle -Q is moving to the right, directly above the wire having a current I flowing to the right, as shown in the figure. In what direction is the magnetic force exerted on the particle due to the current?

A. into the page
B. upward
C. out of the page
D. downward
E. The magnetic force is zero because the velocity is parallel to the current

Answer 1

Using the right-hand rule, the magnetic force on a negatively charged particle moving parallel to a current-carrying wire will be directed into the page. The correct answer is A.

Step-by-step explanation:

The student is asking about the direction of the magnetic force exerted on a charged particle moving in the same direction as the current in a wire. According to the right-hand rule, which determines the direction of the magnetic force, we can find the direction of the force on a negative charge by pointing the thumb of our right hand in the direction of the charge's velocity (to the right), and then curling the fingers in the direction of the magnetic field created by the wire. Since the current I is flowing to the right, the magnetic field B at a point directly above the wire would be coming out of the page. For a negative charge, like -Q, the force will be opposite to the direction indicated by our thumb. Therefore, the force will be into the page.