Electric Current, Voltage, & Power

PHY 100 & 103

Use PDF handouts linked above for three different DC circuits labs. DC Circuits I focuses on current only. Students construct circuits in series and in parallel using light bulbs and batteries. Current through bulbs is associated with bulb brightness and a digital multimeter measures the current through various parts of circuits. Students draw and use basic schematic diagrams. DC Circuits II covers voltage with measurements taken across bulbs and batteries in circuits like those in the previous lab. DC Circuits III provides further exercises and reasoning to establish the relationship between current, voltage and power. All labs compare performance of series and parallel circuits.

Equipment

Notes

Bulbs and batteries should not be in holders at start of lab. Make sure all bulbs are #48. Feinstock clips on holders may have to be adjusted to hold wires securely. Wire should be about 15 cm in length and stripped ends should be straight, not bent or spiraled. Also, check to ensure that the batteries test good for charge and that each table has identical batteries. Put out the orange Extech meter for the Current lab, and then when setting up DC Circuits II and III, add one yellow Sperry meter. (Experiments II and III can be done with only one DMM, but two is preferable.) Display sign stored with meters on instructor's table warning to disconnect batteries and shut off meters.

Along with the initial apparatus set-up, supply a sufficient number of the appropriate paper procedure handouts for all of the lab sections that will use the set-up over the course of the week. Print the PDF, duplicate to double-sided pages, staple, and leave pile on instructor's table prior to first use of set-up.