Question

Beams of electrons and protons having the same linear momentum enter into an electric field normally, which one will deflect more and why?​

Answer 1

Let their velocities at the time of entering the field be vp and ve. vp and ve are given perpendicular to electric field E. Let the field be prevailing over distance d in the direction of initial velocity of the beam.

Now, kinetic energy is same for electron and proton. Therefore,

(1/2)mpvp^2=(1/2)meve^2

So. in given distance, deflections for electrons and protons are same. Then, both trajectory will be equally curved.