Series DC Circuits

Learning Objectives

Measure Voltage and Current with instruments.

Using Ohm's Law to identify the relationship between:

	Circuit Current while adding lamps in series, and
	Circuit Resistance while adding lamps in series.

Equipment

Volt Meter, 2 Amp Meters, lamp board, power supply, and leads with clips.

Procedure

This lab works best with a group of two students.

Series Set-Up 1 Lamp

Make sure the "Circuit" Amp meter is in the circuit with the power supply to the first lamp. Start with the input from the power at the 500 mA terminal. If the reading is less than 50 mA, then move to the 50 mA terminal for a more accurate reading.

	The Volt meter is not in the circuit, it monitors the voltage outside of the lamp. Start with the red probe on the 15 V terminal.
	Keep the power supply off until your setup is checked for safety.

	Turn on the power supply and adjust the output to 5 Volts. Do not adjust the knob again. Use the On/Off switch if needed.
	Refer to Part I in Series Data Collection Worksheet.
	Record the current in mA from the "Circuit" meter in Column B. The "Circuit" and "Lamp" current is the same.

Series 2 Lamps

Move the black wire to the power supply from position #1 to position #2.

	Use the "Lamp" Amp meter to connect the 2nd Lamp. Swap the leads if the meter needle moves below zero.
	Measure and record the voltage across each lamp in Columns C & D. Hint: They should be sharing the voltage!

Record the "Circuit" meter in Column B and the "Lamp" meter in Columns C & D.

Series 3 Lamps

Move the black wire to the power supply from position #2 to position #3.

	Replace the "Lamp" Amp meter with a jumper wire.
	Use the "Lamp" Amp meter to connect the 3rd Lamp.
	Measure and record the voltage across each lamp in Columns C, D & E. Hint: They should be sharing the voltage!

Record the "Circuit" meter in Column B and the "Lamp" meter in Columns C, D & E.

Series 4 Lamps

Move the black wire to the power supply from position #3 to position #4.

	Replace the "Lamp" Amp meter with a jumper wire.
	Use the "Lamp" Amp meter to connect the 4th Lamp.
	Measure and record the voltage across each lamp in Columns C, D, E, & F. Hint: They should be sharing the voltage!

Record the "Circuit" meter in Column B and the "Lamp" meter in Columns C, D E, & F.

Series 5 Lamps

Move the black wire to the power supply from position #4 to position #5.

	Replace the "Lamp" Amp meter with a jumper wire.
	Use the "Lamp" Amp meter to connect the 5th Lamp.
	Measure and record the voltage across each lamp in Columns C, D, E, F, & G. Hint: They should be sharing the voltage!

Record the "Circuit" meter in Column B and the "Lamp" meter in Columns C, D E, F, & G.

Print the Entire Workbook and continue with the Parallel Circuit Lab.