Which formula represents power?

Which formula represents power?

• A. Work divided by time
• B. Time divided by work
• C. Energy divided by current
• D. Current multiplied by resistance

Answer: (A)

Power is the rate at which work is done or energy is transferred. If you do the same amount of work in less time, you’re delivering more power, so power equals work divided by time. That makes P = W/t (or energy per unit time). The other options don’t give power. Time divided by work would be the inverse of power, not power. Energy divided by current has the wrong units for power. Current times resistance gives voltage, not power (though power can be expressed as P = IV or P = I^2R).

Power is the rate at which work is done or energy is transferred. If you do the same amount of work in less time, you’re delivering more power, so power equals work divided by time. That makes P = W/t (or energy per unit time).

The other options don’t give power. Time divided by work would be the inverse of power, not power. Energy divided by current has the wrong units for power. Current times resistance gives voltage, not power (though power can be expressed as P = IV or P = I^2R).