A uniform magnetic field of magnitude 0.20T exists in space from east

1.	A uniform magnetic field of magnitude 0.20T exists in space from east to west. With what speed should a particle of mass 0.010g and having a charge 1.0 x 10-5C be projected from south to north so that it moves with a uniform velocity?
Answer» B = 0.20T, v = ? m = 0.010g = 10^–5kg, q = 1 × 10^-5C Force due to magnetic field = Gravitational force of attraction So, qvB = mg => 1 × 10^–5 × v × 2 × 10^–1 = 1 × 10^–5 × 9.8 => v = (9.8 x 10^-5)/(2 x 10^-6) = 49m/s.

A uniform magnetic field of magnitude 0.20T exists in space from east to west. With what speed should a particle of mass 0.010g and having a charge 1.0 x 10-5C be projected from south to north so that it moves with a uniform velocity?

Answer»

B = 0.20T, v = ? m = 0.010g = 10^–5kg, q = 1 × 10^-5C

Force due to magnetic field = Gravitational force of attraction

So, qvB = mg

=> 1 × 10^–5 × v × 2 × 10^–1 = 1 × 10^–5 × 9.8

=> v = (9.8 x 10^-5)/(2 x 10^-6) = 49m/s.