Answer:
option (B)
Explanation:
mass of proton, m = m
charge of proton, q = e
Time period, T = T
Initially the speed of proton is v.
The time period of the proton when it is moving in magnetic field perpendicular to the direction of magnetic field is given by
[tex]T=\frac{2\pi r}{v}[/tex]
Where, r be the radius of circular path.
The relation between r and the speed v is given by
[tex]r=\frac{mv}{Bq}[/tex]
Where, B be the strength of magnetic field. Substitute this value of r in the expression of time period
[tex]T=\frac{2\pi mv}{Bqv}=\frac{2\pi m}{Bq}[/tex]
Here, we observe that the expression for the time period is independent to v and r so, as we change the velocity, the time period remains same.