Magnetism Problem (1 Viewer)

[MS8]

An electron in a TV CRT moves with a speed of 6.0x10^7 ms, in a direction perpendicular to the Earth’s field, which has a strength of 5.00x10^-5

a) What strength electric field must be applied perpendicular to the Earth’s field to make the electron move in a straight line?

b) If this is done between two parallel plates separated by 1.0cm, what is the voltage applied?

 

[jimmysmith560]

Would the following working help?

Part a):

To make the electron move in a straight line, the total force acting on it must be zero. So, the electric and magnetic force should be equal in magnitude and opposite in direction:





Part b):

The relation between the electric field between the plates of a capacitor and the voltage difference between the two plates is given by:



I hope this helps!