Apositive charge moving up enters a magnetic field pointing out of the screen. what is the direction of the magnetic force on the charge?

a) up
b) down
c) right
d) left

According to the right-hand thumb rule, the forefinger gives the velocity of charge, the thumb gives the magnetic force and the center finger gives the direction of magnetic field.

then, as shown in the picture, the direction of the magnetic force on the charge is in the right direction.