Question

a neutron a proton an electron and an alpha particle enter a region of uniform magnectic field with equal velocities the magnetic field is perpendicular to paper and directed into the paper the track of the particle is given in the fig.

Answer 1

The answer is 4) D

Neutron is having neural charge.
So, it doesn't get deflected.
hence, neutron is C.

Now, proton, electron and alpha- particle are left.

Proton and alpha-particle are both +ve ly charged.
So, they get deflected in same direction....

Thus, A & B are proton and alpha-particle.

D is left and is the electron.....

Answer 2

Hope it helps u........