What does I equal?

• A. Current that follow on a wire or conductor, measured in amps
• B. Voltage at a point in a circuit
• C. Power delivered by a source
• D. Resistance of a circuit

Answer: (A)

I represents electric current—the rate at which electric charges flow through a conductor. It’s the amount of charge passing a point in one second, measured in amperes (amps). In circuits, current is what results from a voltage difference pushing charges through resistance, and it follows the relation I = V / R (Ohm’s law). That means current is the flow quantity, not the potential difference, power, or opposition to flow.

Voltage is the potential difference that drives the current, not I itself. Power describes how quickly energy is transferred, and resistance is what opposes the current. So defining I as the flow of charge in amps is the precise description of what the symbol stands for.