How we use electrical power

When you made the table of the ratings of various household devices, there were a number of boxes you had to leave empty because either the power or the current rating was not given.

write in your journal But now you can fill in the blanks -- for example, the computer monitor uses 1.8 Amperes x 110 V = 200 Watts. Add a few more electrical items to your list -- a light bulb, a radio, a coffee pot, ... so that we get an idea what is going on in those wires around the house. (You can print a new blank table if you like).

Filling in your blanks in the table is more than a math exercise, or a reinforcment of the idea that power = current x voltage -- you also learn how much power different devices use. To put the results into an everyday context, note that if you draw 1000 W for 1 hour (1 kilowatt-hour of energy), you owe the power company about $0.10 (less in Kentucky, where there is lots of coal).


Check the box when you are done: check box 

Electrical safety