Electricity Basics Mastery Assignment
  1. 30 trillion electrons pass a point in a wire in 5 ms. How much current is in the wire?
  2. A stream of plasma generates a current of 25 A when it jumps in the air between two. If this process takes 0.00030 seconds, then how many charges are passing through the air?
  3. The battery in an iPod is rated at 4.4 A•hr. If this battery has a voltage of 10.8 V and runs an iPod for 24 hours before going "dead," then how much current does it draw?
  4. A flashlight is rated at 2 Watts. This flashlight uses 2 rechargable batteries that generate a total of 2.4 V. If these batteries have a rating of 1.800 A•hr, then how time will pass before the batteries go dead?
  5. A toaster plugged into the wall, (120 volts), uses 14 amps of electricity. What is the resistance of the toaster?
  6. A flood light is rated at 300 W. If this is plugged into a typical household outlet then, how much resistance is in the floodlight's filament?
  7. An all electric car uses 56 V while drawing a current of 24 A. How much power does the electric car's motor use?
  8. A hair dyer says it generates 1875 watts. It is plugged into a wall outlet. What is the current drawn by the hair dryer and what is its resistance?
  9. The heating element on a stove is connected to a 240 V outlet. The element draws 20 amps when it is turned on. What is the resistance and power of the element?
  10. The garbage disposal in a sink can generate 3/4 horsepower. If the disposal is plugged into a wall outlet. What is the resistance of the disposal's motor?
  11. A car fuse connected the alternator can handle 12.6 V at 3.97 A. How much power can it handle?
  12. What is the battery voltage of a portable radio that draws 0.500 amps and is rated at 1.5 watts?
  13. What is the value of the charge rating on a 2.6 volt battery that takes 1.6 hours to recharge is the charging device delivers 2.0 amps?
  14. What is the charge value on a watch battery the lasts for 6 months is it draws 0.000300 amps?
  15. A truck battery has a charge rating of 9 Açhrs. If the car takes 550 A's to turn the ignition motor on the car, then how many minutes of can the starter be on until the battery dies?
  16. A hair dryer uses 1875 watts. If electricity costs $0.09/(kW•h), then how long can the hair dryer run before it uses up $0.02?
  17. A security light system is installed in on the outside of the house. The lights in the system are on some number of hours a night. The lights consist of two 150 watts floods. How many hours a night do the lights run for if they are run equal time for 30 days. The cost of electricity is $0.08/(kW•h) and the electric company charges $4.50 to run the lights for 30 days.
  18. A 40 Watt curling iron is plugged into the wall. (A) How much current does the curling iron draw? (B) How much electrical work is done in 1/2 hour?
  19. A 1200 kg all electric car brakes from 25 m/s to rest in 4 seconds. How much current must the car's motor draw from a battery supplying 56 V if it is to use the same amount of power to return to the initial velocity?
As always, ifyou have a question about solving a problem, seek help from the teacher or another student. Every problem must be solved -not "just attempted." You will receive your turned in work immediately after turn it in so it can be checked by you wtih the solution book. The solutions are contained in a notebook in the classroom. You may check the solutions after turning in the assignment. Upon checking your name will be added to the list that allows you take the mastery test. Teh higher of hte two test grades wil be counted.

by Tony Wayne ...(If you are a teacher, please feel free to use these resources in your teaching.)