Power Quiz

What is the unit of power in an electric circuit?

• Joules (J)

• Watts (W)

Which formula is used to calculate power in an electric circuit?

• P = IV

• P = IR

If a 20 V power supply powers a circuit with a 0.5 A current, what is the power delivered to the circuit?

• 5 W

• 10 W

Which of the following equations is derived by combining Ohm's law with the power equation?

• P = IV

• P = I^2R

• P = V^2/R

• All of the above

What is the formula for calculating power (P) in a circuit?

• P = V^2 / R

• P = I^2 * R

If 50 mA of current flows through a 200 Ω resistor, what is the power dissipated by the resistor?

• 0.5 W

• 0.1 W

What is the unit of power?

• Joule

• Watt

What is the common error when giving the units of power?

• Using "watts per second"

• Using "joules per second"

What is the relationship between watts and joules per second?

• 1 W = 1 J/s

• 1 W = 10 J/s

What is the power of a lamp whose current is 6A and the voltage across it is 120V?

• 120W

• 720W