What is voltage defined as in a circuit?

• A. Electrical energy
• B. Electrical current
• C. Electrical resistance
• D. Electrical pressure

Answer: (D)

Voltage is the electrical pressure that pushes charges through a circuit. It’s the potential difference between two points, representing how much energy per unit charge is available to move charges from one point to another. It’s not energy itself, nor the current, nor the resistance. Think of it like water pressure: a difference in pressure drives water flow; likewise, a voltage difference drives current, as long as there’s a path with some resistance. Voltage is measured in volts, with one volt equal to one joule per coulomb. A source like a battery creates this potential difference, and the resulting current follows Ohm’s law, V = IR.