Understanding Power and Energy Concepts

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts

• 3 watts

• 120 watts

• 270 watts

What is the formula to calculate power in an electrical circuit?

• power = voltage / current

• power = current x voltage

• power = resistance x current

• power = voltage x resistance

Which of the following is the correct unit of power?

• Joule

• Watt

• Newton

• Ampere

If a device uses 500 Watts of power for 3 hours, how much energy does it consume?

• 1500 Joules

• 1500 Watts

• 1500 Watt-hours

• 1500 Newtons

A light bulb operates at a voltage of 240 volts and a current of 0.5 amperes. What is the power consumed by the light bulb?

• 120 Watts

• 480 Watts

• 240 Watts

• 60 Watts

Which of the following equations correctly represents the relationship between energy, power, and time?

• energy = power / time

• energy = power x time

• energy = time / power

• energy = power + time

If a machine has a power rating of 2 kW and runs for 5 hours, how much energy does it use?

• 10 kWh

• 10 Joules

• 10 Watts

• 10 Newtons

Which of the following is NOT a unit of power?

• Horsepower

• Watt

• Joule

• Kilowatt