Proton traveling across a capacitor A proton enters with a velocity v between the plates of a capacitor as shown in the figure. What is the direction of the magnetic field needed so that the proton continues its trajectory, undeflected? Explain each step of your reasoning.

Please see the direction of force in the attachment

Explanation:

As the particle enters the capacitor, it experiences electric. In order to move in the same direction as the electron was moving before entering the capacitor, the force due to the electric field of capacitor must be balanced by the magnetic field.

The direction of particle is shown in the attachment.

As we know,

Force = q (v *B)

c. newton's third law of motion