Physical Science Electricity/Magnetism 4B2.00 Unifying Concepts of Science Interactions 2.4 a

CURRICULAR CORRELATIONS

CONTENT STANDARD: Physical Science

CONTENT TOPIC: Electricity/Magnetism

CONCEPT: Electric current may travel along one or more paths.

CONTENT OBJECTIVE: 4B2.00 To understand the parts of a complete circuit

INSTRUCTIONAL OBJECTIVES: The learner will:

2.01 define electrical circuit.
2.02 distinguish between closed and open circuits.
2.03 define electric current.
2.04 identify switch as a conductor.
OUTLINE OF CONTENT:
I. Electrical current defined
II. Electrical circuit defined
III. Closed circuit
IV. Open circuit
V. Switch

TN COMPONENT OF SCIENCE: Unifying Concepts of Science

TN GOAL:

To enable students to acquire scientific knowledge by applying concepts, theories, principles and laws from life/environmental, physical, and earth/space science.
TN THEME:
2.4 INTERACTIONS - At all levels of living and non-living systems, matter and energy act and react to determine the nature of our environment.
TN STANDARD(S): The learner will understand that:
2.4a Interactions occur on scales ranging from elementary particles to galaxies.

BENCHMARK Interactions among the smallest particles determine the nature of matter. Interactions among larger collections of matter determine its behavior.

BENCHMARK The same fundamental particles are present in both living and non-living matter. The interactions of these particles shape our universe.

CLASSROOM CONNECTOR

TIME REQUIRED:

One instructional period
MATERIALS:
Flashlight bulbs, D-batteries, bulb holder, wire, switch, tape, scissors
SET:
Have you ever stopped to think of how much we depend on electricity? (response) How many things do you see that run on electricity? (response) (List these on the chalkboard.) How does the electricity reach those things? (response) Today, we will learn about how electricity reaches these things.
INSTRUCTION:
Current electricity is the flow of electrical energy by means of charges moving through a conductor such as copper wire. Sources of electrical current such as batteries, generators, or large power plants, produce a difference of electrical energy called potential difference (measured in volts) which causes electricity to flow from the source to the device and back to the source.

In another type of electricity, negative charges move through matter. The negative charges move in one direction like a stream of water. This is called current electricity. The electric current must move along a path. This path must lead back to its starting point. The path can be shaped like a loop or circle. The path is called a circuit. An activity to show this is as follows:

1. You need a flashlight bulb, a bulb holder, a flashlight battery, two wires, and tape.

2. Screw the bulb into the bulb holder.

3. Tape the end of one wire to the bottom of the battery. Screw the other end of the wire to the bulb holder.

4. Tape the end of the second wire to the top of the battery.

5. Touch the loose end of the wire to the screw on the bulb holder. Observe what happens. Wires, bulbs, and batteries can be connected together. When they are connected correctly, they make a pathway for electricity. We call the flow of electricity, an electric current. The pathway that electricity follows is called a circuit. Electric current moves, or flows, through a closed circuit. The bulb's light is a closed circuit.

6. Take away the loose wire, so that it no longer touches the bulb holder. What happens? Can you explain the answer? When you touch the loose wire to the bulb holder, you close the circuit and the bulb lights. But when you take away the loose wire, you break the circuit and the bulb does not light.

Electric current from a battery flows in one direction. And it flows only when the circuit is closed, or complete. When there is a break in the circuit, no electricity flows. In that case, we say the circuit is open.

You close a circuit when you turn on a light. You open the circuit when you turn off a light? What do we use to turn a light off or on? (a switch) Have students install a switch in the above activity. What happens to the circuit when the switch handle is up?

CLOSURE:
What is the difference between an open and closed circuit? Share your answer with your neighbor. With your neighbor, explain in a paragraph how a battery operated vehicle (toy) works. Use the terms open, closed, circuit, electric current, wires, battery, and switch in your explanation.
ENRICHMENT:

Home electricity is measured with a meter. The electric company reads meters once a month. Invite a meter reader to the classroom to teach children how to read their home dials.

This is the time this file has been accessed since 07/01/97.

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