A charged particle with a charge-to-mass ratio of |q|/m = 5.7 x 10^8 C/kg travels on a circular path that is perpendicular to a magnetic field whose magnitude is 0.69 T. How much time does it take for the particle to complete one revolution?

Answer 1

ma=F
mv²/R =qvBsinα.

v⊥B => sinα = 1.
mv/R =qB,
R = mv/ qB,

T=2πR/v=2π m /qB=
= 2π/B(q/m) =2π/0.69•5.7•10⁸0.69= =1.6•10⁻⁸ s