Question

A particle of mass 10 mg and having a charge of 50 mC is projected with a speed of 15 m/s into a uniform magnetic field of 125 mT. Assuming that the particle is projected with its velocity perpendicular to the magnetic field, the time after which the particle reaches its original position for the first time is ______.

Options

• 14 s

• 12 s

• 10 s

• 8 s

Answer 1

A particle of mass 10 mg and having a charge of 50 mC is projected with a speed of 15 m/s into a uniform magnetic field of 125 mT. Assuming that the particle is projected with its velocity perpendicular to the magnetic field, the time after which the particle reaches its original position for the first time is 10 s.

Explanation:

Given,

Mass of particle, m = 10 mg = 10 × 10^-6 kg

Charge of the particle, q = 50 × 10^-6 C

Speed of the particle, v = 15 m/s

Magnetic Field, B = 125 × 10^-6 kg 10^-3 T

Time period, T = `(2pi"m")/"qB"`

`= (2(3.14)(10 xx 10^-6))/((50 xx 10^-6)(125 xx 10^-3))`

`= (6.28 xx 10)/(625 xx 10^-2)`

= 10 S