"Breaker Breaker" Created by Doug Spicher
Elkridge Landing Middle School

Elkridge, Maryland

This lesson is designed for grade 8 and should take about one 30 minute period.

Name:____________________________________

Date:____________________________________

Class:___________________________________

Breaker Breaker!

# Introduction

The movement of electrons (electricity) causes friction, which in turn causes heat. Wires are rated by their ability to carry current. If they are forced to carry too much current, they can overheat causing circuits to short out or fires to start. Along comes the circuit breaker. The circuit breaker is exactly what its name implies. It breaks if a circuit becomes overloaded with current. The idea is that most homeowners would rather replace a blown circuit than replace an entire home if a circuit becomes overloaded.

Inthis activity, you will model a circuit breaker.

# Materials

• 2 pieces of wire with the insulation removed from each end

• 2 pieces of electrical tape

• 2 batteries

• 2 alligator clips or clothes pins

• small piece of steel wool

# Procedures

1. Attach one end of each wire to each alligator clip. Do not connect the clips!!!

2. Attach one wire to the positive end of one battery.

3. Attach the other end to the negative end of the other battery.

4. Stretch the steel wool piece between the alligator clips and attach it to each of the jaws. The steel wool should now be stretched!

5. Very carefully put the wireless positive and negative poles together.

6. Disconnect as soon as something happens. You will likely need to make sure that the “teeth” on the clip are in contact with the steel wool. Also, you will likely have to play around with the distance the clips are from each other.

# Questions and Conclusions

1. What happened?
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2. Why did it happen?
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3. What advantages are there to having a circuit breaker?
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4. What, if any, disadvantages are there to circuit breakers?
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5. Your teacher has a variety of materials for you to test as circuit breakers. See if your results are the same with two more metals.
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6. What determines the material that is best to use for a circuit breaker?
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7. If a circuit breaker breaks, or is tripped, what happens to the circuit? Explain!
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"Breaker Breaker" Created by Doug Spicher