Question

A beam of protons enter the electric field of magnitude E = 0.5 N/C between a pair of parallel plates. There is a magnetic field between the plates. The magnetic field is parallel to the plates and perpendicular to the initial direction of the protons, and its magnitude is 2.3 T. The proton beam passes through undeflected. What is the speed of the protons?

Answer 1

Answer:

0.217 m/s

Explanation:

The protons in the beam passes undeflected when the electric force is equal to the magnetic force:

qE = qvB

where

q is the proton's charge

E is the magnitude of the electric field

v is the speed of the protons

B is the magnitude of the magnetic field

Re-arranging the equation,

$v=\frac{E}{B}$

And by substituting

E = 0.5 N/C

B = 2.3 T

We find

$v=\frac{0.5}{2.3}=0.217 m/s$