- #1

pcandrepair

- 67

- 0

## Homework Statement

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?)

## Homework Equations

F(B) = qvB

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

## 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!