What power is produced when a device has 1 volt across it and draws 1 amp of current?

What power is produced when a device has 1 volt across it and draws 1 amp of current?

• A. 0 watts
• B. 2 watts
• C. 1 watt
• D. 10 watts

Answer: (C)

Power is how fast energy is used, and it equals voltage times current. With 1 volt across the device and a current of 1 amp, the power is P = V × I = 1 × 1 = 1 watt. A watt means one joule of energy per second, so the device uses energy at 1 joule per second. If either voltage or current were different, power would change accordingly (e.g., 2 watts would require twice the voltage at the same current, or twice the current at the same voltage).

Power is how fast energy is used, and it equals voltage times current. With 1 volt across the device and a current of 1 amp, the power is P = V × I = 1 × 1 = 1 watt. A watt means one joule of energy per second, so the device uses energy at 1 joule per second. If either voltage or current were different, power would change accordingly (e.g., 2 watts would require twice the voltage at the same current, or twice the current at the same voltage).