# Ohm’s law & electric power problems

*Solve the following problems. Show your work and make sure your answers have the correct units!*

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**Ohm’s Law and Electrical Power Practice Problems**

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1. What resistance would produce a current of 200 A with a potential difference of 2,000 V?

2. What is the current produced with a 9 V battery through a resistance of 100 ohms?

3. What voltage produces a current of 50 A with a resistance of 20 ohms?

4. What is the current produced by a potential difference of 240 V through a resistance of 0.2 Ω?

5. What resistance would produce a current of 120 A from a 6 V battery?

6. Silver has a resistance of 0.00198 ohms. What voltage would produce a current of 100 A?

7. Find the current when a 12 V battery is connected through a resistance of 25 ohms.

8. A 12 V battery produces a current of 25 Amps. What is the resistance?

9. A current of 250 A is flowing through a copper wire with a resistance of 0.0209 ohms. What is the voltage?

10. A 9 V battery produces a current of 2.0 A. What is the resistance?

11. If a power source provides 54 watts of power to operate a machine that draws 4.5 amps of current when in use, what is the voltage used by the machine?

12. A nightlight uses 3.5 watts of power when plugged into an outlet. The current in the nightlight’s circuit is 0.034 amps. What is the voltage in the nightlight?

13. If a generator provides 33600 watts of power to a motor and the voltage across the motor is 440 volts, what is the current in the motor?

14. A mixer uses 200 W of power. If the mixer is plugged into a 120 volt outlet, what current is in the mixer’s circuit?

15. A coil on an electric stove draws 1250 W of power while using 240 volts. What is the current in the coil?

16. What is the power rating of an appliance that uses 8 amps of current when plugged into a 120 volt outlet.

17. A toaster plugged into a 120 volt household circuit draws 5.4 amps of current. What is the power of the toaster?

a. What is the resistance of the toaster?

18. A clothes dryer in a home has a power of 4,500 watts and runs on a special 220 volt outlet. What is the current through the dryer?

a. What is the resistance of the dryer?