(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An electron in a cathode ray tube is accelerated through a potential difference of ΔV = 11 kV, then passes through the d = 4 cm wide region of uniform magnetic field. What field strength (in mT) will deflect the electron by 10(degrees)? (Hint: is it a reasonable approximation to treat the magnetic force on the electron as being in a constant direction?)

2. Relevant equations

F(B) = qvB

v = [tex]\sqrt{(-2*e*V/Mass(e))}[/tex]

3. The attempt at a solution

Using the equation for velocity, I found that the velocity of the electron when leaving the "accelerator" has a velocity of v = 6.21601628 x10^7 m/s

I also found that the electron is deflected .007053m down when passing through the magnetic field.

I'm not sure where to go from here.... Would I find the force of the magnetic field, (F(B)), and then find the magnitude of B using the equation given above? If so, how would I do this? Thanks for any help!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Electron deflection in a cathode ray tube

**Physics Forums | Science Articles, Homework Help, Discussion**