Find the magnitude of the force on an electron that is travelling with velocity 2 x 10^4 ms^(-1) in the x direction through a uniform magnetic field of strength 2T in the y direction.

This question tells us we only need to consider the magnitude of the force, and since the magnetic field and electron's velocity are perpendicular, we can simply use the equation

F = Bqv.

We have B = 2 T, q = 1.6 x 10-19 C (the charge of an electron) and v = 2 x 104 ms-1.

Substituting these values into the equation gives 

F = 2 * (1.6  x 10-19 ) * (2 x 104) = 6.4 x 10-15 N   (Remember your units!)

SH

Related Physics A Level answers

All answers ▸

A 80kg man is hanging from two 1.5m ropes that lie at 60 degrees from the horizontal. What is the tension in each rope required to prevent the man from dropping?


what would be the mass required to keep an object with a mass of 250kg orbiting at a constant distance of 100km with a linear velocity of 100m/s?


A stone is thrown horizontally at 5m/s from a platform 10m above ground. Find time till impact with ground.


A car of mass M and a maximum power output of P is on an rough inclined plane Θ to the horizontal. What is the maximum velocity (v). Coefficient of friction=μ and air resistance=kv where k is constant