Electrolysis Practice Exam

What must be present for current to flow?

1. Resistance

2. Voltage

3. Current

4. Capacitance

The correct answer is: Voltage

For current to flow, there must be a difference in electric potential, known as voltage. Voltage acts as the driving force that pushes electric charges through a conductor. When a voltage is applied across a conductor, it creates an electric field that causes the charge carriers (such as electrons) to move, resulting in the flow of electric current. Resistance, while it is a factor in the overall circuit that affects the amount of current that flows for a given voltage (Ohm's Law), is not a prerequisite for current to initiate; it simply serves to limit or control the current flow. Current itself cannot exist without the flow of charge; therefore, it is a result of voltage. Capacitance relates to the ability of a system to store electric charge, but it does not directly contribute to the initiation of current flow. Hence, voltage is essential for establishing the conditions necessary for current to occur.