How can 1 wire, 1 battery, and 1 bulb be used to make a complete circuit?

What about 2 wires, 1 battery, and 1 bulb?

Pathfinders

For the device to work, the electrical energy must flow in a complete or closed circuit.

Circuit Diagram

Basic circuits require the following components:

• An energy source (electricity or a dry cell)

• A conductor (usually a wire or something made of metal)

• A device to operate (resistor)

Basic Circuits

Would This Work?

Would This Work?

Would This Work?

Would This Work?

Would This Work?

The Central Concept: Closed Circuit

Open and Closed (Complete) Circuits

Closed Circuit Open Circuit Complete Circuit

Switches

Series D

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Series D

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Series D

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Series D

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Connect 1 bulb to your batteries

• Draw a diagram and write one sentence describing what happened.

Connect a total of 2 bulbs to your batteries

• Draw a diagram and write one sentence describing what happened.

Connect a total of 3 bulbs to your batteries

• Draw a diagram and write one sentence describing what happened.

Series Circuits (L)

What happened as you added more bulbs to your series circuit?

Why do you suppose that is?

How many paths does the electrical current have to flow through?

Stop and Think

What do you think would happen if we removed a bulb from a series circuit?

1. Set up a series circuit with 1 bulb.

2. Now, come and pick up a bulb holder with the bulb removed.

3. What happened to the other bulb?

4. Why?

Removing a Bulb

Series D

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Series D

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• Series circuits have one and only one path for an electrical current to flow through.

• The current flows through every part of the circuit.

In a complete series circuit, the more bulbs or devices that are added, the ____________________________

____________________________________________.

If one bulb is removed, then _____________________

____________________________________________.

Series Circuits (R)

Toys that use batteries

Cell Phones

Computers and Tablets

Blenders

Televisions

Holiday Lights (old fashioned)

Any others??

Series Circuit Examples

Make a series circuit with 1 bulb

• Draw a diagram and write one sentence describing what happened.

Making Parallel Circuits

Make a series circuit with 1 bulb.

Next, connect a total of 2 bulbs to your battery like this:

• Draw a diagram and write one sentence describing what happened.

Parallel Circuits (L)

Now add a third bulb in your parallel circuit like this:

• Draw a diagram and write one sentence describing what happened.

Parallel Circuits (L)

What happened as you added more bulbs to your parallel circuit?

Why do you suppose that is?

How many paths does the electrical current have to flow through?

Stop and Think

What do you think would happen if we removed a bulb from a parallel circuit?

1. Set up a parallel circuit with 2 bulbs.

2. Now, come and pick up a bulb holder with the bulb removed. Swap it out with one of the bulbs in your parallel circuit.

3. What happened to the other bulb?

4. Why?

Removing a Bulb

Parallel D

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Parallel D

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Parallel D

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Parallel D

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Parallel D

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Parallel D

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• Parallel circuits have more than one path for an electrical current to flow through.

• Have at least one point where the current divides or splits into different branches.

In a complete parallel circuit, the more bulbs or devices that are added, the ________________________________

________________________________________________.

If one bulb is removed, then _________________________

________________________________________________.

Parallel Circuits (R)

School and business lighting and outlets

Household lighting and outlets

Electrical wiring in cars

Microwave

Refrigerator

Holiday lighting (newer strands)

Any others??

Parallel Circuit Examples

Lights in a Series Circuit

Lights in a Parallel Circuit

Series and Parallel Circuits

Batteries in Series & Parallel

Comparison

Series Circuit Parallel Circuit

Definition

Resistance

Examples

Only one path for

current to flow

Multiple paths for

current to flow

Total resistance

increases

Total resistance

stays same

-Holiday lights

(traditional)

-Household

Current