Given-

Velocity of the proton, v = 3 × 10⁶ m s⁻¹

Uniform magnetic field, B = 0.6 T

As per the question, the proton is projected perpendicular to a

uniform magnetic field.

We know, Newton’s second law, Force F is given by –

where

m is mass of the object

a=acceleration

For proton

Magnetic force, we know, Lorentz force F is given by -

where,

e = charge on an electron

v = velocity of the electron

B=magnetic field

θ= angle between B and v

Equating (1) and (2),

As θ = 90⁰