Which statement best explains why a voltage difference can drive current in a circuit?

Which statement best explains why a voltage difference can drive current in a circuit?

• A. Because voltage is the same everywhere
• B. Because voltage is the resistance
• C. Because voltage differences create an electric field that does work on charges moving between points
• D. Because voltage is the mass of electrons

Answer: (C)

The driving factor is the electric field set up by a voltage difference. That potential difference creates an electric field in the circuit, and this field exerts a force on charges (F = qE). As charges move under this force, the field does work on them, giving them energy to travel around the loop. The amount of energy each unit charge gains corresponds to the voltage difference, and this continuous action of the field pushes charges through the conductor, producing current. If there were no voltage difference, the field would vanish and there’d be no net force to move charges, so no current. The other statements mix up what voltage represents (it isn’t a resistance or mass, and it isn’t the same everywhere).

The driving factor is the electric field set up by a voltage difference. That potential difference creates an electric field in the circuit, and this field exerts a force on charges (F = qE). As charges move under this force, the field does work on them, giving them energy to travel around the loop. The amount of energy each unit charge gains corresponds to the voltage difference, and this continuous action of the field pushes charges through the conductor, producing current. If there were no voltage difference, the field would vanish and there’d be no net force to move charges, so no current. The other statements mix up what voltage represents (it isn’t a resistance or mass, and it isn’t the same everywhere).