Question

Consider the following statements:
A) Time period of a charged particle in uniform magnetic field is independent of K.E of the particle
B) Time period of a charged particle in uniform magnetic field depends on the angle between velocity and magnetic field
C) Time period of a charged particle in uniform magnetic field is inversely proportional to specific charge

• A. A, B are correct and C is wrong
• B. A is correct, B and C are wrong
• C. A, C are correct and B is wrong
• D. A, B & C are correct

Answer 1

Answer: (C)

A, C are correct and B is wrong

$\frac{m{V}^2}{r}=qVB$

$m\frac{V}{r}=qB$

$w=\frac{qB}{m}$ $(\because wr=V)$

$\frac{2\pi }{T}=\frac{qB}{m}$ $(\because w=\frac{2\pi }{T})$

$T=\frac{2\pi m}{qB}$

So, time period is independent of K.E. of particle, it is inversely proportional to specific charge of the particle and it is independent of angle between velocity and magnetic field.