A proton and a deuteron are moving with equal velocities perpendicular to a uniform magnetic field.A deuteron has the same charge as the proton but has twice its mass.The ratio of the magnetic force on the proton to that on the deuteron is:
A)0.5.
B)1.
C)2.
D)There is no magnetic force in this case.

Question

Quizplus · Accepted Answer

The magnetic force acting on a charged particle moving with a velocity perpendicular to a uniform magnetic field is given by F=qvB, where q is the charge, v is the velocity and B is the magnetic field. Since both the proton and deuteron are moving with equal velocities, the only difference in the magnetic force acting on them is due to their charges and masses. As the charges are the same, the ratio of magnetic forces will be proportional to the ratio of their masses. Therefore, the ratio of the magnetic force on the proton to that on the deuteron is given by (mp/mD)=0.5/1=0.5, where mp and mD are the masses of the proton and deuteron, respectively. Therefore, the answer is B.

A Proton and a Deuteron Are Moving with Equal Velocities