Electric Power Concepts Quiz

Which of the following is NOT an equation for calculating electric power?

• Power = Current^2 x Resistance

• Power = Voltage^2 / Resistance

• Power = Current x Voltage

• Power = Voltage x Resistance

If a DC traction motor operates at 72 volts and 5000 watts, what is the current it draws?

• 69 amps

• 100 amps

• 72 amps

• 5000 amps

How much energy does a 1200-watt hairdryer use in 5 minutes?

• 600,000 joules

• 120,000 joules

• 240,000 joules

• 360,000 joules

Which unit is used to measure energy in the context of electric power?

• Volts

• Amps

• Watts

• Joules

What is the formula to calculate energy used when power and time are known?

• Energy = Power + Time

• Energy = Power x Time

• Energy = Power / Time

• Energy = Power - Time

What is the resistance of a light bulb that uses 72 watts of power and draws 0.8 amps of current?

• 0.8 ohms

• 72 ohms

• 113 ohms

• 90 ohms

How much energy is required to start a car engine that needs 250 amps for 1.5 seconds?

• 4,500 joules

• 3,000 joules

• 6,000 joules

• 2,500 joules

What is the power rating of an immersion heater with 12 volts and 15 ohms of resistance?

• 9.6 watts

• 12 watts

• 15 watts

• 18 watts

In the context of electric power, what does the term 'work' refer to?

• The resistance in a circuit

• The rate at which energy is used

• The voltage across a component

• The amount of current flowing

What is the relationship between power, current, and voltage?

• Power = Current / Voltage

• Power = Voltage - Current

• Power = Current x Voltage

• Power = Voltage / Current