Your new toaster has two separate toasting units, each of which consumes 600 watts of power when it is in use. When you operate one unit, a current of 5 amperes flows through the wiring in your home and the wires waste about 1 watt of power handling that current. If you operate both toasting units at once, your toaster consumes 1200 watts and the current flowing through the wiring in your home doubles to 10 amperes. How much power will the wires in your home waste now?
A) about 0.5 watts.
B) about 4 watts.
C) about 2 watts.
D) about 1 watt.

Question

Quizplus · Accepted Answer

The power wasted in the wires is proportional to the square of the current (P = I^2 * R, where P is power, I is current, and R is resistance). If 1 watt is wasted with 5 amperes, then with 10 amperes (double the current), the power wasted will be 4 times as much (since 10^2 / 5^2 = 4), resulting in 4 watts wasted.

Your New Toaster Has Two Separate Toasting Units, Each of Which