Ohm’s Law & Electric Power Problems

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

 

Ohm’s Law and Electrical Power Practice Problems

 

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?