Problem set on power, current, voltage and resistance:
1. How many amperes does a 100 watt bulb require when operating on 120
volts?
2. A 250 watt radio will draw how many amps when operating on 240 volts?
3. How many ohms of resistance are present in a light bulb that draws 2 amperes
at 120 volts?
4. A device that is powered by two 1.5 volt batteries draws 0.0015 amperes.
What is its total resistance?
5. An iron that heats with the power of 1200 watts at 120 volts is turned on. How
much current does it draw? Will a 15 ampere fuse blow?
6. How many ohms resistance are in a 120 volt hair dryer that draws 8 amps?
How many watts of power are used?
7. You have two equations, V = IR and P = IV. Can you perform some
substitutions and come up with new equations? If you can, what might they
mean?
8. A stereo needs 200 watts of power, and you know your house provides 120
volts of AC electricity. How much current does the stereo draw?
9. How much resistance does the stereo in problem #8 give to the charges in the
wire?
10. If the fuse on your circuit breaker can only take 10 amps, will plugging in your
stereo from #8 blow the fuse if you also plug in your disco ball that draws 60
watts of power?