The symbol I is used to denote which electrical quantity?

• A. Voltage
• B. Resistance
• C. Power
• D. Current

Answer: (D)

Current is the flow of electric charges through a conductor, and the symbol I is used to denote this quantity. It represents how much charge passes a point per unit time and is measured in amperes (A). This is different from voltage, which is the potential difference between two points and uses the symbol V, and from resistance, which is the opposition to current and uses the symbol R. Power is the rate of energy transfer and uses the symbol P, related by P = V × I. In Ohm’s law, current relates to voltage and resistance as I = V / R, showing how increasing voltage or decreasing resistance increases current. In DC circuits, conventional current is considered to flow from higher to lower potential; in AC circuits the current direction reverses periodically but the symbol I continues to represent current.