Question

A proton moves vertically upward and perpendicular to a uniform magnetic field. It deflects to the left as you watch it. What is the magnetic field direction?

Answer 1

The magnetic field will be directed away from me into the screen

Step-by-step explanation:

The force on a positive charge in a magnetic field can be shown by Lorentz right hand rule. If the palm of the left hand is held out with the fingers (representing the field) held parallel to the palm, and the thumb (representing the direction of motion of the positive charge), held perpendicular to the rest of the fingers. The palm will push in the direction of the force on the charge.

Having this in mind, if the thumb points vertically up, with the with the pal facing the left, then the fingers (representing the field) points away from me into the screen.