U1C2A4

The Electric-Circuit Interaction

Exploration #1

2. How many connections are there to each element

in the circuit?

Answer: Two Connections.

3. When does an electric-circuit interaction occur?

Answer:

An electric-circuit interaction occurs when a source of electric current

(ex: battery/cell) is connected in a COMPLETE LOOP with conducting

wires to an electrical device

(ex: light bulb).

Exploration #24. In order for an electric-circuit

interaction to occur, the type(s) of materials that must be included in

the circuit is (are) metal.

The evidence is that when we placed metals objects within the loop the bulb lit

up, but when we placed nonmetal objects such as paper and plastic, the

bulb did not light up.

6. Unscrew one of the two light bulbs from its socket. Leave the

other bulb alone. What happened to the other bulb?

Answer: it goes out!

8. Unscrew one of the two light bulbs from its socket. Leave the

other bulb alone. What happened to the other bulb?

Answer: it remains lit!

9. Why do you think the result for Question 8 was different from the

result for Question 6?

Answer: In a parallel circuit (Q.#7), each bulb has its own separate loop to the

cell and electricity still flows in this separate closed circuit.

9. Why do you think the result for Question 8 was different from the result

for Question 6?

Answer: However, in a series circuit (Q.#5), the bulbs are in a single loop and electricity doesn’t flow when the

circuit loop is is open (one bulb unscrewed).

Exploration #4

10. Is the bulb in this two-cell and one-cell bulb circuit brighter than, dimmer

than, or equally as bright as the bulb in the one-cell, one-bulb circuit in

Exploration 1?

Answer: Brighter.

11. Is the bulb in this two-cell and one-cell bulb circuit brighter than,

dimmer than, or equally as bright as the bulb in the one-cell, one-bulb

circuit in Exploration 1?

Answer: it’s brighter.

12. Write your conclusion for this exploration by answering the following

question in a complete sentence.

If the number of cells in the circuit increase, what happens to the brightness of the bulb?

Answer:

As the number of cells in a circuit increase, the brightness of the bulb increases.

13. What is your hypothesis about the relationship between the number of cells and the amount of electric current?

Answer:

The more cells, the greater the amount of electric current because when we hooked up two cells and one bulb in a series circuit, the bulb glowed lighter.

50.1 mA

70.3 mA

85.5 mA

98.2 mA

#14

increases

as the number of cells increase from 1 to 2 to 3 to 4 , the amount of electric current increases from 50.1 mA to 70.3 mA to 85.5 mA to 98.2 mA.

Let’s Review

Make Sense of Your IdeasMake Sense of Your Ideas

#s 1-4

1. power source (cell) 2. electrical device (light bulb) 3. wires

by wires in a complete loop

change in illumination- when the light bulb is glowing (on) electric current is flowing through the circuit

LINK

What is the evidence that an electric-circuit interaction has occurred?

When does an electric-circuit interaction occur?

the electric current stops flowing so the electrical device turns off

What happens when there is a break in the electric-circuit?

What happens when there is a break in the electric-circuit?

5. What variable or variables can influence the electric-circuit interaction?

What is your evidence?What is your evidence?

variable = # of light bulbs

bulbs bulbs brightnessbrightness

1 bulb1 bulb 2 bulbs2 bulbs

variable = how devices are connected

series circuit series circuit oror single-loop single-loop

circuitcircuit

parallel circuitparallel circuit oror multi-loop multi-loop

circuitcircuit

variable = how devices are connected

•In a series circuit- unscrew 1 bulb then they all go out

In a parallel circuitIn a parallel circuit- - unscrew 1 bulb then unscrew 1 bulb then the others stay onthe others stay on

variable = # of cells

cells cells brightnessbrightness

cells electric current

50.1 mA70.3 mA

85.5 mA 98.2 mA

5. What variable or variables can influence the electric-circuit interaction? What is your evidence?What is your evidence?• Exploration 3- variable was adding bulbs to circuit

with one cellbulbs bulbs brightnessbrightness

• Exploration 3- variable was changing how we connected the bulbs (series and parallel circuits)

• In a series circuit- unscrew 1 bulb then they all go out• In a parallel circuit- unscrew 1 bulb then the others stay on

• Exploration 4 & 5 adding cells to a circuit with 1 bulb

cells cells brightness brightness cells electric current (amperes)

#6 Holiday Lights

• Read and answer carefully. This will be graded for correctness.

#7 Lamps at home

• Read and answer carefully. Be sure to explain how you know.

Answer the Key Questions

• Use the back of your paper to fully answer the key questions.

What are the defining characteristics of an electric-circuit interaction?

Key Question #1

Summarize your answers to Making sense of your ideas #s 1-4

What are some variables that influence the electric-circuit interaction?

Use making sense of your ideas #5 to answer this question (hint- there are THREE (3) variables)

Key Question #2

How do batteries generate electricity?

Video Quiz!

Video Quiz AnswersVideo Quiz Answers

1.C

2.B

3.A

4.C

5.D

Stop here and use a red pen.

• We will now correct your answers.

• Use red pen or a pen of a different color than your answers only.

Make Sense of Your IdeasMake Sense of Your Ideas

#s 6-7

• Type A – series

• Type B – parallel

Parallel circuit because if I turn 1 lamp off, the other stays on.

What are the defining characteristics of an electric-circuit interaction?

Key Question #1

Summarize your answers to Making sense of your ideas #s 1-4

Key Question #1(Summarize #s 1 & 2)

Key Question #1(Summarize #s 1 & 2)

• An electric-circuit interaction occurs when a power source is connected to electrical device by wires in a complete loop

Summarize # 3

Key Question #1 (Summarize # 3)

• if electric current is flowing then the electrical device is working/on (ex: light bulb is glowing)

Summarize #4

Key Question #1(Summarize #4)

•when there is a break in the loop/circuit the electrical device will stop working because the electric current is NOT flowing

Key Question #2Key Question #2

Re-read Make Make Sense of Your Sense of Your

IdeasIdeas # 5

series or parallel?

series or parallel?

Look back over Explorations 3, 4 and 5

variable = how devices are connected

series circuit series circuit oror single-loop single-loop

circuitcircuit

parallel circuitparallel circuit oror multi-loop multi-loop

circuitcircuit

variable = how devices are connected

•In a series circuit- unscrew 1 bulb then they all go out

In a parallel circuitIn a parallel circuit- - unscrew 1 bulb then unscrew 1 bulb then the others stay onthe others stay on

variable = # of cells

cells cells brightnessbrightness

cells electric current

50.1 mA70.3 mA

85.5 mA 98.2 mA

Key Question #2

1. The number of cells

2. The way you hook up electrical devices to an electrical source

Grade Yourself

• 3 points for labeling the parts in the pictures from exploration 1 and 3.

• 5 points for answering the key questions completely and correctly.

• 2 points for answering #6 (holiday lights) and #7 (lamps) of making sense of your ideas correctly.

• Write the total out of 10 points at the top Write the total out of 10 points at the top of the front of the record sheet.of the front of the record sheet.

Electric-Charge vs. Electric-Circuit

The way you hook up electrical devices to an electrical source

series

parallel

The way you hook up electrical devices to an electrical source

Change the way you hook up the wires (series or parallel circuits): EVIDENCE- in a series circuits if you unscrew 1 light bulb, the other light bulb goes out…..in a parallel circuit if you unscrew 1 light bulb, the other light bulb stays on

increasing the number of cells

increases the amount of electric current flowing in the circuit

EVIDENCE = the light bulb glows brighter, mA increased