Physics › Electric Field and Electric Potential
A charged particle traveling along the +x axis enters an electric field directed vertically upward along the +y-axis. If the charged particle experiences a force downward because of this field, what is the sign of the charge on this particle?
It is negative
It is positive
It is neutral
None of these
Positive charges in an electric field will experience an electric force that is in the same direction as the electric field. If the charge is negative, the force will be in the opposite direction of the electric field. Since the charged particle experiences a force which is opposite to the electric field, the sign of the charge must be negative.