1. Lesson 2: Series and Parallel Circuits
Energy Basics
Mr. Conkey Physical Science/Project Recharge Unit 1
Lesson 2: Series and Parallel Circuits

2. Lesson 2: Learning objectives
I will be able to construct series and parallel circuits in order to explore ways to operate more than one component at a time in a circuit
I will be able to demonstrate evidence of the flow of electricity through a light bulb

3. Essential Questions
Can multiple receivers be powered in a single circuit?
How can single circuits power multiple receivers at the same power level?

4. Activity 1: Series Circuits to light multiple bulbs
How can you get two bulbs to light at the same time?
First, draw your schematic diagram for what you think the series circuit will look like (in box 1 of your handout)
Now, build your series circuit!
Why do you think the lamps are dim in a series circuit?
Can you make the two lights brighter in your series circuit?
Remind students of simple circuits by drawing a schematic of a circuit (bulb, battery, and switch) and review vocab. After first question, hand out the Advanced Connections sheet. Materials needed: 1 circuit base, 1 D-cell, 2 Bulbs in holders, 3 short wires, and 1 switch. Write ideas for dim lights on the board. Tell students two lights in a series is a problem (too dim for use), then ask them the final question on the slide. Have students pair up with another group for additional materials.

5. Two cells in a series
D-cell orientation – if both cells are pointing in the same direction, the bulbs produce bright light; if they are pointing in opposite directions, the bulbs will not light
Now describe what you figured out about D-cells in a series
Draw a schematic diagram of your successful circuit into box 2 of your Advanced Connections sheet
Ask students to describe what they figured out about D-cells in series. Have students draw a schematic diagram of the circuit that successfully lit two bulbs brightly into box 2 of their Advanced Connections sheet; have them label their diagrams “series circuit.”

6. Series Circuits
Series circuit – has two or more components attached to a source in such a way that the current follows only one pathway through all the components, one after the other (share a source)
Resistance – some materials such as tungsten filaments resist the flow of eˉ s by creating, in effect, a bunch of road- blocks

7. Switches in Circuits
Short circuit – a low-resistance conductor that bypasses a component
Can be dangerous (e.g. the hot paperclip)
Single pole/single throw (SP/ST) switch – on/off simple circuit switch
Single pole/double throw (SP/DT) switch – can control two different circuits
Can complete one circuit or the other or turn them both off, but cannot turn both circuits on at the same time

8. Activity 2: Building Parallel Circuits
Challenge: build a different circuit using two bulbs!
Draw the schematic of your circuit in box 3 of your Advanced Connections sheet
Have students talk in their group about the new circuit and when they have an idea give them the materials needed (1 circuit base, 1 D-cell, 2 bulbs in holders, 4 short wires). Encourage students to assemble, take apart, and reassemble as many ways as they can think of (one way per student if possible); then have students draw a schematic of the circuit in box 3 of their Advanced Connections sheet. Finally, have several students draw diagrams on the board.

9. Parallel Circuits
Parallel circuit – has two or more components, each with an equivalent pathway on a circuit (do not share a source)
The current leaving the cell has two pathways it can follow (follow the wires)

10. Class list of questions
Come up with a list of questions or ideas for new and more complex circuit investigations (at least 5 per group)
Sample question (do not use this!): Would another D-cell affect the brightness of two bulbs connected in a parallel circuit?

11. Series vs Parallel Circuits Quiz (answer on the back of the Circuit review sheet handout)
What do we call a circuit in which all the components are connected in one big circle so there is only one pathway for electricity to flow?
Why do you think the lights are dim when only one battery is used?
Is the orientation of the batteries important when you use two in a series circuit? Explain.
How does electricity flow through a parallel circuit?
Which circuit can run more components from a single D-cell? Why is this?