Which unit is used to measure electrical power?

Which unit is used to measure electrical power?

• A. Amperes (amps)
• B. Volts
• C. Watt-hours
• D. Watts

Answer: (D)

Power in an electrical circuit is the rate at which energy is transferred or converted. In the SI system, the unit for this power is the watt, defined as one joule per second and equal to one volt times one ampere. So, watts measure how much electrical power a device uses at any instant. Watt-hours, on the other hand, measure energy over time (how much energy is used overall), not the instantaneous power. Amperes measure current—the amount of charge flowing—while volts measure potential difference. So they describe other aspects of the circuit, not the rate of energy transfer. Thus, the unit used to measure electrical power is watts.

Power in an electrical circuit is the rate at which energy is transferred or converted. In the SI system, the unit for this power is the watt, defined as one joule per second and equal to one volt times one ampere. So, watts measure how much electrical power a device uses at any instant.

Watt-hours, on the other hand, measure energy over time (how much energy is used overall), not the instantaneous power. Amperes measure current—the amount of charge flowing—while volts measure potential difference. So they describe other aspects of the circuit, not the rate of energy transfer.

Thus, the unit used to measure electrical power is watts.