In an electrical circuit, what causes the flow of current?

• A. Voltage
• B. Resistance
• C. Temperature
• D. Magnetism

Answer: (A)

The flow of current in an electrical circuit is primarily caused by voltage, which is the electrical potential difference between two points in the circuit. Voltage serves as the driving force that pushes electric charges through the circuit. When a voltage is applied across a conductor, it creates an electric field that causes electrons to move, resulting in the flow of current.

Resistance is a property of materials that opposes the flow of current, and while it plays an essential role in determining how much current flows for a given voltage (as described by Ohm's Law), it does not cause the flow of current itself. Temperature can affect resistance and the behavior of materials in a circuit but is not a direct cause of current flow. Magnetism, while related to electricity through electromagnetic principles, does not directly cause current to flow in a typical electrical circuit. Therefore, voltage is the correct answer because it initiates and sustains the flow of electrical current.