FAA Aviation Mechanic General (AMG)Fundamentals of Electricity and ElectronicsMedium
A circuit operating at 120 volts draws a current of 5 amperes. What is the power consumed by the circuit?
- A600 W
- B25 W
- C120 W
- D24 W
Show answer & explanationAnswer & explanation
Correct answer: A. 600 W
Electrical power is calculated as P = I × E = 5A × 120V = 600 watts.
Why the other options are wrong
- B. This is I² without multiplying by resistance or voltage correctly.
- C. This is only the voltage value, not power.
- D. This is E/I, not the power formula.
Electrical Power Formula
Power in a DC circuit equals current multiplied by voltage (P=IE), measured in watts.
- P=I×E
- Also P=I²R or P=E²/R
- Watt is the unit of power
- Power indicates rate of energy use
Memory trick: Power is what lights the bulb — multiply the push (E) by the flow (I).