Question

In cyclotron, an ion is made to travel successively along semicircles of increasing radius under the action of a magnetic field. The angular velocity of the ion is independent of
A. speed of ion
B. radius of the circle
C. mass of the ion
D. charge of the ion

Answer 1

Correct Answer - B
Here, as wer know is cyclotron centripetal force on charge is equal to magnetic force `F_c=F_m`
So `(mv^2)/(r)=qvBimpliesv/r=(qB)/(m)`
[As `v=romega`, So `V/r=omega`]
So `omega=(qB)/(m)` [i.e., Independent of v, r]