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 ▸You have a layer of glass with a refractive index of 1.5 and the glass is surrounded by air. A light ray shines into the glass and Total Internal Reflection occurs at the glass-air boundary. What is the critical angle?
How can an object be accelerating when it's velocity is constant, and how does centripetal acceleration work.
How do you explain why puddles evaporate on cold days ?
What is the minimum initial velocity necessary for an object to leave Earth?