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
Answered by Sally H. Physics tutor

17336 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

What does the double slit experiment tell us about light?


What is the definition of a moment?


State and derive Kepler's third law


From the 2016 OCR B paper A ball is thrown at an angle of 30 Degrees to the horizontal. The initial kinetic energy of the ball is K. Air resistance is negligible. What is the kinetic energy of the ball at the maximum height.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning