If electron, proton, neutron and alpha particle are deflected in the same electric field with same velocity. What will be deflection in them?
A. Proton less than electron
B. Proton more than electron
C. Electron More than alpha particle
D. Proton more than alpha particle
Explain the answer.

The lorentz force gives you your answer here. Strength of magnetic field times velocity of the particle perpendicular to the field times charge of the particle = force applied to the particle perpendicular to both the field and the particle’s current direction.

If these are the same for both the electron and proton, then the same force will be applied.

However, acceleration is proportional to force over mass, and since the proton is about 8,000 heavier than the electron, it’s radius of curvature will be about 8,000 greater.