# Ohm’s Law and Series Circuits

Name of Activity

Ohm’s Law and Series Circuits

Author

STOMP

Keywords

circuit, electricity, Ohm’s Law, voltage, resistance, current

Subject

Non-LEGO

4, 5, 6, 7, 8, 9+

Time

1 Hour Total

Brief Description

Students will build a simple circuit using previous knowledge about electricity. They will use Ohm’s Law to analyze the circuit.

Lesson Objectives:

– To introduce electricity, circuits, and electrical engineering.

– To apply Ohm’s law to real circuits.

Materials Needed:

– 24 Gauge AWG wire, cut to 8 inch lengths w/stripped ends. Give each student group 5 – 6 8 inch pieces.

– 9V battery with connector plate.

– 2 1-Watt light bulbs with lamp bases.

– 2 Toggle switches.

– Alligator clip.

Preparation and Set Up:

– Make a copy of the worksheet for each student.

– Prepare a demo circuit.

– Arrange students in groups of 2 – 3.

– Distribute materials.

Necessary Background

Ohmâ€™s Law describes the relationship between the voltage, current, and resistance of a circuit. This relationship is given in the relationship Voltage = Current x Resistance. Knowing this relationship, it is possible to find any of the three values as long as the other two are known.

Vocabulary:

Ohm’s Law

Voltage

Resistance

Current

Procedure

1. Go though slides 6 – 8 of the attached Powerpoint
2. Go over your demo circuit and calculate the current using Ohm’s law Current (amps) = Voltage/Resistance
1. Voltage can be found on the side of a battery (9V for this activity).
2. Resistance is about 81 ohms for each light bulb.

• Distribute the worksheets and materials and assist the students in creating the circuits and calculating the current using Ohm’s law.
• Extensions or Modifications:

Design on paper a circuit of your choice, using whatever size battery and resistors you want. Calculate the Voltage, Resistance and Current in your circuit. Your teacher will show you a circuit that she or she has built. Draw a circuit diagram representing it.

Reference 1

http://sites.tufts.edu/stompactivitydatabase/files/formidable/o1.png

Reference 2

http://sites.tufts.edu/stompactivitydatabase/files/formidable/o2.pdf

Reference 3

http://sites.tufts.edu/stompactivitydatabase/files/formidable/o3.pdf

Reference 4

http://sites.tufts.edu/stompactivitydatabase/files/formidable/o4.pdf

Reference 5

http://sites.tufts.edu/stompactivitydatabase/files/formidable/o5.pdf

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