Final answer:
Yes, the net force on an electron in a uniform magnetic field can be zero if the electric field is present that exactly opposes the magnetic force, matching it in magnitude and opposite in direction.
Step-by-step explanation:
The question asks whether the net force on an electron in a region with a uniform magnetic field can be zero given that an electric field is also present.
The net force on an electron in a magnetic field is given by the Lorentz force, which is the sum of the electric force (qE) and the magnetic force (qvB, where v is perpendicular to B). To make the net force zero, an electric field (E) must be present that exactly opposes the magnetic force. This means the electric field must be equal in magnitude and opposite in direction to the magnetic force on the electron. Hence, it is possible for an electron to move without deflection if an electric field with precise characteristics is also applied to the region.