Question

An electron and a proton , having equal moment , enter a mag. field at an angle 90° with field lines. What will be the ratio of their trajectories?

Answer 1

Momentum of both electron and proton are equal. - (Given)

Then , P = mv is (constant).

We know that,

F = q v B sin θ.

(Here , F - force, q - charge, v - velocity, B - magnetic field)

This force provides the required centripetal force for the motion along circular path whose radius is r.

Centripetal force = mv^2/r

Then,

Mv^2/r=qvb sin θ

Here, θ = 90 degrees .

Then,

R = mv/bq

= 1:1