Answer:
By a magnetic field: no
By an electric field: yes
Explanation:
The force exerted by a magnetic field on an electron is
[tex]F=qvB sin \theta[/tex]
where
q is the electron charge
v is the speed of the electron
B is the strength of the magnetic field
[tex]\theta[/tex] is the angle between the direction of v and B
As we see from the formula, if the electron is at rest, then v = 0, and therefore the force is also zero: F = 0. Therefore, the magnetic field cannot set the electron into motion.
On the other hand, the force exerted on an electron by an electric field does not depend on the speed:
[tex]F=qE[/tex]
where E is the intensity of the electric field
Therefore, the electric force acts also when the electron is at rest, so it is able to set the electron into motion.
