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 ▸

Explain the photoelectric effect, when does it occur and what is its significance in understanding the nature of light ? (6)


What is the change in temperature of 2kg of water heated by a kettle using a voltage of 230V at 0.5A of current for 10 seconds? Assume no heat losses.


Why does a skydiver go through two different terminal velocities?


Compare and contrast geostationary and low polar orbits.