When Thomson experimented with his apparatus, he noticed that in one run, the electron beam dropped 1.35 cm. when it emerged from the parallel plate region (where the electric and magnetic fields were present). If L = 5 cm, E = 1000 volts/meter, determine the value of the B-Field in Tesla.
Should I use the equation B~Sq. Root of (E) (theta angle) (me)/(eL)?
I think I need a rad number for the angle. How would I figure this out?