Question

A charged particle is undergoing a circular motion in a uniform magnetic field, now speed of particle is doubled, then

• A. Radius remains same.
• B. Angular speed remains same.
• C. Time period becomes half.
• D. Magnetic force becomes half.

Answer 1

The correct option is B Angular speed remains same.

at equilibrium
$qvB=\frac{m{v}^2}{r}$
$r=\frac{mv}{qB}$
$T=\frac{2\pi r}{v}=\frac{2\pi m}{qB}$
$w=\frac{2\pi }{T}=\frac{v}{r}=\frac{qB}{m}$
(independant of speed)