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 Tq = 1.6 x 10-19 (the charge of an electron) and v = 2 x 10ms-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 ▸

The tip of each prong of a tuning fork emitting a note of 320Hz vibrates in SHM with an amplitude of 0.50mm. What is the speed of each tip when its displacement is zero?


How can the average speedx of a gas molecule be derived?


How do I find how much radioactive material is left after time t if I know its half-life?


How does the strong nuclear force between two nucleons varies with separation of the nucleons. Please detail the range over which the force acts.