Investigation 13

House Circuits and Appliances

I.Your Home Circuits:

Find the circuit breaker box (or fuse box) for your house or apartment. In the space below, draw a fairly accurate diagram of the box showing the switches (or fuses). Label each of the switches (or fuses) with the maximum current amperage it can handle and the part of the house or apartment it controls. (In many cases the part of the house or apartment controlled by the switch (or fuse) is identified on a card inside the box. If you are not sure what part of your house or apartment the switch (or fuse) controls, then you can turn the switch off (or unscrew the fuse) and see what electrical items go off. (Make sure everyone in your home is agreeable to this.) If you have fuses, you must be very, very careful when loosening them.)

II.Connections for Home Electrical Circuits

The batteries in the circuits you workedon in theprevious investigation act very much like the voltage sources supplied to your home by the electric company, and the bulbs in the investigation act like the electrical devices in your home. The big difference is that the batteries deliver DC and the electric company delivers AC. This voltage supplies the energy needed to power the electrical devices in your home.

A.From what you found in the investigation, do you think that the electrical devices in your home are connected in series or parallel? How do you know?

B.Why is it dangerous to connect too many lights and electric devices to one electrical circuit?

III.Electrical Devices in Your Home

Choose three different types of electrical devicesin your home, and find the label on them that shows the Underwriter’s Laboratory (UL) logo. For each item, record the information on the label that indicates voltage and current or voltage and power. (For example, my fan indicates 120 V and 0.8 A and my AC-DC converter indicates 120 V and 6 W.) If voltage and current are given, then calculate the power; if voltage and power are given, then calculate current.

Remember:

and

Item / Given Quantities / Calculated Quantity (Show your calculations.)