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Electrical Experiments Circuits_ Electromagnets_ and Motors

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									                 Electrical Experiments

       Circuits, Electromagnets, and Motors




Student Project for ENGR 3030 “Service Learning Engineering Design”

                    Western Michigan University

                        Spring 2005 Semester


         Jenna Hiller, Andrew Rockwell, and James Spencer




                Faculty Advisor: Dr. Andrew Kline


         Revision, further testing, and editing in Spring 2006
           by Paula Lupina, American Humanics Intern




                   Classroom tested in April, 2005

          Additional Testing in February and March, 2006
            at the Kalamazoo Area Boys and Girls Club




                                                                      1
Activity 1: Circuit Board

Useful Terms for Circuit Board Activity:

  Voltage:     potential difference across an object measured in volts
  Current:     flow of electric charge
Amperage:      the rate of flow of a current of electricity expressed in amperes
 Terminal:     a device attached to the end of a wire or cable or to electrical equipment
               for making connections
   Circuit:    the complete path of an electric current
  Resistor:    any object that resist the movement of electrical charge
    Series:    an arrangement of the parts of or elements in an electric circuit whereby
               the whole current passes through each part or element without branching
   Parallel:   an arrangement of electrical devices in a circuit in which the same
               potential difference is applied to two or more branches

Brief comments: Within the figures the red line represents a connecting wire with an
alligator clip at each end and a yellow circle indicates that the bulb should be lit. The
figures and explanation position wires to specific bulbs, different bulb can be used as
long as the same pattern is used.

  Supplies:    Provided circuit board and accessories




                               Figure 1: Circuit Board Setup




Student Activity Sheet                         Circuit Board                                1
Figure 2.


   •   Take one connecting wire and attach it to the (positive) +terminal (by attaching
       the clip to the terminal wire).
   •   Take the other end of the same connecting wire and attach it to one of the screws
       on the Bulb 2 mount.
   •   Take another connecting wire and connect it to the opposite screw on the Bulb 2
       mount and to the (negative) -terminal.


   This should light up Bulb 2 when the connecting wires are attached.




                                  Figure 2: Single Lit Bulb




Student Activity Sheet                       Circuit Board                                 2
   Figure 3


   •   Disconnect the connecting wire from the (negative) -terminal and connect it to a
       screw on Bulb 3.
   •   Now take a third connecting wire and connect it to Bulb 3 and to the (negative)
       -terminal. Figure 2 shows two light bulbs in series.
   •   Now disconnect one of the connecting wires (does not matter which one).
       Observe what happens.
   •   Remove all connecting wires




                             Figure 3: Two Lit Bulbs in Series




Student Activity Sheet                       Circuit Board                                3
   Figure 4


   •   Take one connecting wire and attach it to the (positive) + terminal (by attaching
       the clip to the terminal wire).
   •   Take the other end of the same connecting wire and attach it to one of the screws
       on Bulb 1 mount.
   •   Take another connecting wire and connect it to the other screw on Bulb 1 mount
       and to the (negative) - terminal.
   •   Now repeat this with a Bulb 3.


   Figure 4 shows two light bulbs in parallel.


   •   Now disconnect one of the connecting wires (does not matter which one).
       Observe what happens.
   •   Remove all connecting wires




                             Figure 4: Two Lit Bulbs in Parallel




Student Activity Sheet                       Circuit Board                                 4
   Figure 5
   •   Take one connecting wire and attach it to the (positive) + terminal (by attaching
       the clip to the terminal wire).
   •   Take the other end of the same connecting wire and attach it to one of the screws
       on Bulb 2 mount.
   •   Take another connecting wire and connect it to the other screw of Bulb 2 mount.
   •   Take the other end of the same connecting wire and to Bulb 1 mount.
   •   Take another connecting wire and connect it to the other screw of Bulb 1 mount.
   •   Take the other end of the same connecting wire and to Bulb 3 mount.
   •   Take another connecting wire and connect it to the other screw on Bulb 3 mount.
   •   Take the other end of the same connecting wire and connect to the (negative)
       -terminal.
   Figure 5 shows three bulbs in series.
   •   Remove all of the connecting wires




                             Figure 5: Three Lit Bulbs in Series




Student Activity Sheet                       Circuit Board                                 5
   Figure 6
   •   Take one connecting wire and attach it to the (positive) + terminal (by attaching
       the clip to the terminal wire).
   •   Take the other end of the same connecting wire and attach it to one of the screws
       on Bulb 1 mount.
   •   Take another connecting wire and connect it to the other screw on Bulb 1 mount
       and to the (negative) - terminal.
   •   Repeat with Bulb 2.
   •   Repeat with Bulb 3.
   Figure 6 shows three bulbs in parallel.




                             Figure 6: Three Lit Bulbs in Parallel




Student Activity Sheet                       Circuit Board                            6
   Figure 7a
   •   Disconnect the connecting wire from the (positive) +terminal and Bulb 1.
   •   Disconnect the connecting wire from Bulb 2 and the (negative) -terminal and
       connect it to a screw on Bulb 1.




                  Figure 7a: Combination with Three Bulbs (All Lit)




Student Activity Sheet                      Circuit Board                            7
   •   Next use 3 bulbs and show combinations of series and parallel.
          o Can you make 2 bright, 1 dim, etc.
          o Examples of this looks like:




                  Figure 7a: Combination with Three Bulbs (Two Lit)




                 Figure 7a: Combination with Three Bulbs (None Lit)

Student Activity Sheet                      Circuit Board               8
Figure 8
   •   Remove all connecting wires.
   •   Take one connecting wire and attach it to the (positive) +terminal (by attaching
       the clip to the terminal wire).
   •   Take the other end of the same connecting wire and attach it to one of the screws
       on the Bulb 1 mount.
   •   Take another connecting wire and connect it to the opposite screw on the Bulb 1
       mount and to the side screw of Switch 2
   •   When the switch is down the circuit is complete and Bulb 1 will light up. When
       the switch is up, the circuit is broken and the bulb will not light up.
           o The next diagram is of a switch. When power is connected to the top or
             side points and the switch is up, power is supplied to the top two points
             and each side point.




                         Figure 8: Cold and Hot Switch Diagrams




Student Activity Sheet                       Circuit Board                                 9
Figure 9 and 10
   • Can you make a series/parallel circuit using a switch?
   • Now add a third light using a switch.
   • See what types of circuits you can create using both switches
   • Can you light up just bulb 1 or just 2 and 3, etc




                        Figure 9: Two Bulbs in Series with Switch




              Figure 10: Two Lit Bulbs in Parallel with Two Switches
Clean up: Make sure that all pieces of the circuit board are still in place and return the
board to the teacher.
Student Activity Sheet                        Circuit Boards                               10
Activity 2: Electro magnet


Useful Terms for Electro Magnet Activity:


        Current: flow of electric charge
      Amperage: the rate of flow of a current of electricity expressed in amperes
 Magnetic Field: a force that attracts or repels electrons and is produced when an
                 electrical charge flows through wire


        Supplies: Thin wire (two foot lengths provided by teacher), a long nail or long
                  bolt, two 1.5 volt C-cell batteries, paper clips


   1. See if the nail/bolt will pick up paper clips.
   2. Leave a 4 inch length of copper wire, then start wrapping the copper wire around
      the nail/bolt leaving at least a 4 inch length at the end. Try to make as many coils
      as possible without overlapping it. A single layer of wire is all that is necessary.
   3. See if the nail/bolt wrapped in copper wire will pick up paper clips.
   4. Connect the batteries from the circuit board to the wires at each end.
   5. See if the electro magnet attracts paper clips.


Clean up: Give all materials back to teacher.




Student Activity Sheet                          Electro magnet                               1
Activity 3: Motors


Useful Terms for Motors:


        Current: flow of electric charge
      Amperage: the rate of flow of a current of electricity expressed in amperes
 Magnetic Field: a force that attracts or repels electrons and is produced when an
                 electrical charge flows through wire


Supplies:      Coil of wire, battery, magnet


    1. Use special caution when handling the coil, trying not to bend any part of it. If it
       is bent, it will not to work.
    2. Place magnet in slot at top of battery holder.
    3. Set the coil of wire on the stand over the magnet.
    4. Connect the battery to the assembly.
    5. Hold another magnet in various positions about the coil


Clean up: Give all materials back to teacher.




Student Activity Sheet                            Motor                                       1
Teacher Lecture Material

Appendix 1: Circuit Board Teacher Instructions

Pre-assembly Instructions (done by the teacher):

First cut peg-board into 12” by 18” sections. Drill two holes in two of the corners of the
battery mounts and use screws to screw them into the peg-board. Use another two screws
to mount each switch. Do the same with the lamp mounts. Screw down a piece of
thicker wire or metal shim for the terminals. Connect the battery mounts in series, with
one side connected to the terminal, and the other to each switch.

For safety: Cut small pieces of tubing to thread onto screws on the back of the peg-board
that were used for switches, terminals and battery holders. Cut small pieces of corrugated
cardboard to place over the screws on the back of peg-board that were used for the lamp
mounts, then cover with duct tape.

The final product should resemble Figure 1.




                              Figure 1: Circuit Board Setup




Teacher Lecture Materials                     Circuit Board                             1
Standards Addressed:          (PME) IV.1 e.4, (PME) IV.1 m.5

Objectives:
  • To show students the difference between parallel and series circuits.
  • To show students how to use a switch.

Background Information:

   •   Voltage is the measure of the potential difference, and batteries are the perfect
       example of this. Each end of the battery is charged. Chemicals inside the battery
       cause the electrons to move to one end. Conventional ideology is that electrons
       flow from the positive point to the negative, but the opposite is true. Electrons are
       forced to the negative end of the battery and, when the two ends are connected in
       a circuit, they flow towards the positive end. This statement also infers another
       definition.
   •   Current is the flow of electrons. An analogy of current can be water flowing
       through a pipeline. Just as water flows, so do electrons. As the potential is
       increased like the pressure of a water pump, more electrons will flow.
   •   Resistance is anything that impedes the initial flow of electrons. Light bulbs and
       space heaters are two examples of large resistors. These work by using their
       resistance to hinder the current to produce energy that is released in the form of
       heat and light. Also, the wire forming the circuit and the battery both have
       internal resistance. Even our bodies have a large resistance to the flow of
       electrons, but this is true for most non-metal items. Therefore, metal objects have
       the least amount of resistance and are utilized for the flow of electricity.
   •   Electrical circuits operate under a few basic concepts. A potential difference is
       placed across an object, and electrical charge flows between the points. What
       makes a circuit important is that electrical equipment can be placed in line with
       the flow of charge to operate. Circuits can also be set up in several ways to
       accommodate for multiple components.
   •   Series is an arrangement of the parts of or elements in an electric circuit whereby
       the whole current passes through each part or element without branching. Two
       light bulbs in series mean that the light bulbs are connected in a straight line with
       each other where the electricity has to flow through one bulb to get to the other.
       The positive end of one bulb is connected to the negative of the other. The
       benefit of series circuits is that the current never changes. Two disadvantages are
       that the voltage decreases as it passes each light bulb or resistor, and if a bulb is
       removed, the circuit is broken, current cant flow to the other end of the battery,
       and the rest of the circuit wont work.
   •   A parallel circuit is a closed electrical circuit in which the current is divided into
       two or more paths and then returns via a common path to complete the circuit.
       When a circuit is in parallel, multiple lines connect each end of the battery.


Teacher Lecture Materials                      Circuit Board                                2
       Parallel also represents how the light bulbs are placed in the circuit. The positive
       end of one bulb is connected to the positive end of the other and the negative ends
       are connected to each other. Now if one bulb is broken or removed, the other will
       still work. This is because the battery is still connected to the other light bulb.
       Another advantage to parallel is that a higher voltage is maintained across each of
       the multiple lines. The main disadvantage is that the current decreases as it is
       divided between the lines, which decrease the number of light bulbs you can
       effectively operate on each leg of the circuit.
   •   Examples: A house is a good example of an operating parallel circuit. When a
       light or a T.V. is turned off, the rest of the house still has electricity. If the house
       were in series, every appliance would have to be turned on for the whole house to
       have electricity. This is because current must always have a path to flow to the
       battery, or the circuit is broken and electricity won’t flow. Because electricity
       follows the path of least resistance, it is easy for a short circuit to occur. If a bare
       wire with no light bulbs attached to it is connected to the two ends of the circuit,
       most of the current will travel through it rather than the rest of the circuit. This
       will cause the other light bulbs to not have enough current to power them.
       Understanding circuits and electricity will help show students how many things
       involved in our daily lives are affected by science.


Teacher Instructions:

Start off showing the kids how to make 1 light work by demonstrating on the board
provided for the teacher. Then show how to put 2 lights in series, and then 2 in parallel.
Allow them time to experiment with the board on their own and develop hypotheses for
how and why things work on the board. Ask questions to get the students thinking about
the differences between parallel and series: brightness change (bulbs are brighter in
parallel), what happens if one light in series is taken out as opposed to what happens if
light in parallel circuit is taken out.

       The figures and explanation position wires to specific bulbs, different bulb can be
       used as long as the same pattern is used.

Single Lit Bulb (figure 2) – Take one connecting wire and attach it to the (positive)
+terminal (by attaching the clip to the terminal wire). Take the other end of the same
connecting wire and attach it to one of the screws on the Bulb 2 mount. Take another
connecting wire and connect it to the opposite screw on the Bulb 2 mount and to the
(negative) -terminal. This should light up Bulb 2 when the connecting wires are attached.

Two Lit Bulbs in Series (figure 3) – Disconnect the connecting wire from the (negative) -
terminal and connect it to a screw on Bulb 3. Now take a third connecting wire and
connect it to Bulb 3 and to the (negative) -terminal. Figure 2 shows two light bulbs in
series. Now disconnect one of the connecting wires (does not matter which one).
Observe what happens. Remove all connecting wires




Teacher Lecture Materials                       Circuit Board                                 3
Two Lit Bulbs in Parellel (figure 4) - Take one connecting wire and attach it to the
(positive) + terminal (by attaching the clip to the terminal wire). Take the other end of
the same connecting wire and attach it to one of the screws on Bulb 1 mount. Take
another connecting wire and connect it to the other screw on Bulb 1 mount and to the
(negative) - terminal. Now repeat this with a Bulb 3. Now disconnect one of the
connecting wires (does not matter which one). Observe what happens. Remove all
connecting wires

Using an analogy may help the students’ understanding of the circuits. Explain this by
the water flowing through pipes analogy. Describe electrical current as water, the wires
as pipes, and the bulbs as things that resist flow of water. When the pipes in series are
disconnected, the water cannot flow back to the source. Also when in parallel, the water
is not slowed down by the first light it encounters.


Next use 3 bulbs and show combinations of series and parallel. Test to see if they can set
up 2 in parallel and 1 in series, and how could they tell by looking at the brightness of the
lights.

Three Lit Bulbs in Series (figure 5) - Take one connecting wire and attach it to the
(positive) + terminal (by attaching the clip to the terminal wire). Take the other end of
the same connecting wire and attach it to one of the screws on Bulb 2 mount. Take
another connecting wire and connect it to the other screw of Bulb 2 mount. Take the
other end of the same connecting wire and to Bulb 1 mount. Take another connecting
wire and connect it to the other screw of Bulb 1 mount. Take the other end of the same
connecting wire and to Bulb 3 mount. Take another connecting wire and connect it to the
other screw on Bulb 3 mount. Take the other end of the same connecting wire and
connect to the (negative) -terminal. Remove all of the connecting wires

Three Lit Bulbs in Parallel (figure 6) - Take one connecting wire and attach it to the
(positive) + terminal (by attaching the clip to the terminal wire). Take the other end of
the same connecting wire and attach it to one of the screws on Bulb 1 mount. Take
another connecting wire and connect it to the other screw on Bulb 1 mount and to the
(negative) - terminal. Repeat with Bulb 2. Repeat with Bulb 3.

Combination with Three Bulbs (All Lit, Two Lit, and None Lit) (figure 7a -3 versions) –
Disconnect the connecting wire from the (positive) +terminal and Bulb 1. Disconnect the
connecting wire from Bulb 2 and the (negative) -terminal and connect it to a screw on
Bulb 1. Next use 3 bulbs and show combinations of series and parallel. Can you make 2
bright, 1 dim, etc.

Cold and Hot Switch Diagrams (figure 8) - Remove all connecting wires. Take one
connecting wire and attach it to the (positive) +terminal (by attaching the clip to the
terminal wire). Take the other end of the same connecting wire and attach it to one of
the screws on the Bulb 1 mount. Take another connecting wire and connect it to the
opposite screw on the Bulb 1 mount and to the side screw of Switch 2. When the switch
is down the circuit is complete and Bulb 1 will light up. When the switch is up, the
circuit is broken and the bulb will not light up. The next diagram is of a switch. When

Teacher Lecture Materials                      Circuit Board                                4
power is connected to the top or side points and the switch is up, power is supplied to the
top two points and each side point.

Two Lit Bulbs in Series with One Switch (figure 9) and Two Lit Bulbs in Parallel with
Two Switches (figure 10) - Can you make a series/parallel circuit using a switch? Now
add a third light using a switch. See what types of circuits you can create using both
switches. Can you light up just bulb 1 or just 2 and 3, etc.

For lead-in discussion: Ask students what they think circuits are/what they are used for.
Ask for examples of different ways that they are used in everyday life.




Teacher Lecture Materials                     Circuit Board                                 5
Appendix 2:Electro Magnet Teacher Instructions

Pre-assembly Instructions (done by the teacher):

Cut enough two foot lengths of bare copper wire so that each group has a copper wire.

Standards Addressed: (PMO) IV.3 m.4

Objectives:
To show students how to make an electro magnet.

Background Information

Electro magnets are just like permanent magnets except they only work when electric
current is flowing through the wire. The figure below (left) shows the shape of the
magnetic field around the wire. In this figure, imagine that you have cut the wire and are
looking at it end-on. The green circle in the figure is the cross-section of the wire itself. A
circular magnetic field develops around the wire, as shown by the circular lines in the
illustration below. The field weakens as you move away from the wire (so the lines are
farther apart as they get farther from the wire). You can see that the field is perpendicular
to the wire and that the field's direction depends on which direction the current is flowing
in the wire.




                                 Figure 11: Magnetic Fields

One way to amplify the strength of the magnetic field is to coil the wire. The picture on
the right is an illustration of a coiled wire. If you coil this wire around a nail/bolt, then
the nail/bolt has a magnetic field around it and becomes magnetized.


Teacher Instructions

Electro magnets will be created by the students. They will be given a nail/bolt and two
feet of wire. They will wrap the wire around the nail/bolt as much as possible without
overlapping the wire. Keep the two ends of the wire exposed so that it can be attached to
the batteries on the circuit board.

Teacher Lecture Materials                      Electro Magnet                                   1
For lead-in discussion: Ask students how they think magnets are formed. Are they found
in nature or are they made? Or both?

(Magnets are formed in nature and can also be created synthetically. They can be found
naturally occurring in objects such as rocks or can be created from metals such as iron,
steel, and nickel.)




Teacher Lecture Materials                   Electro Magnet                                 2
Appendix 3: Motor Teacher Instructions

Pre-assembly Instructions (done by the teacher):

   1. Unwrap the wire and straighten out any bends. Leaving about two inches straight,
      (about the length of a D-cell battery), wrap the wire around the battery to form a
      coil. (Figure 1) Unwrap a small amount from the second end so that you now have
      about two inches of wire sticking out from either side. (Figure 2)




             Figure 1                                                 Figure 2

   2. Each end of the wire is wrapped tightly around the coil for two turns. (Figure 3)
      This will keep the coil together. The two ends should stick out directly opposite
      of each other and should be at least one inch long. Excess can be trimmed or
      wrapped around the coil as additional turns.



                                          Figure 3

   3. The wire is covered with an enamel coating for insulation. Hold the coil
      vertically and then rest one of the wire ends n a flat surface. (Figure 4) Using the
      edge of a metal support, scrape the enamel coating off the entire top half of the
      wire end. Turn the coil slightly as you scrape so that the top half of the wire is
      scraped bare. Do not scrape the bottom half of the wire. Repeat this for the
      second wire sticking out from the opposite end of the coil. The enamel is left on
      the bottom half of each wire. (Figure 5)




             Figure 4                                                  Figure 5
   4. Slide the metal supports up through the slots in the plastic base. The bump in the
      metal faces towards the battery. (Figure 6)




Teacher Lecture Materials                        Motor                                    1
                                           Figure 6
Standards Addressed: (PME) IV.1 e.4

Objectives:
To show students how a motor works.

Background Information

The motor is a loop of wire that is connected to a battery and suspended over a magnet.
Electric motors exist to convert electrical energy into mechanical energy. This is done by
way of two interacting magnetic fields. A stationary field is created by a magnet and
attached to the base of the motor. The wire coil produces the other field when electricity
is passed through it, which is shown in the figures above. Electric motors, like the electro
magnet, operate only when an electric current is passed through the loop.


Teacher Instructions

Have students connect the battery and put the magnet into the designated hole. Then
have students place the loop of wire onto the wire brackets.

For lead-in discussion: Ask students’ ideas about what a motor is/how a motor could be
created. Brainstorm ideas of how a motor could be created with the objects provided for
this experiment. After students have thought through the experiment on their own; show
the correct way to make a motor from the objects.




Teacher Lecture Materials                         Motor                                   2
Appendix 4: Additional Information for the Teacher

Definitions:

Voltage: potential difference across an object measured in volts
Current: flow of electric charge
Amperage: the rate of flow of a current of electricity expressed in amperes
Terminal: a device attached to the end of a wire or cable or to electrical equipment for
making connections
Circuit: the complete path of an electric current
Resistor: any object that resist the movement of electrical charge
Series: an arrangement of the parts of or elements in an electric circuit whereby the
whole current passes through each part or element without branching
Parallel: an arrangement of electrical devices in a circuit in which the same potential
difference is applied to two or more branches
Magnetic Field: a force that attracts or repels electrons and is produced when an
electrical charge flows through wire

Other Notes for the Teacher:

-Only minor construction and rearranging will be required for students to perform the
experiments.

-A few hours to half a day would be appropriate for these activities. A “science day”
with a circuitry/magnetism/electricity theme would be suitable.

-A literacy component can be integrated into these activities in many different ways.

       One way would be to have students write out their own hypothesis about what
       will happen in each of the experiments before they complete the experiment. This
       will give the students a chance to write about the experiments using what they
       know already. They could then share their predictions with other students and see
       if their ideas change after talking with classmates about their predictions.

       Another way to integrate a writing project would be to have the students write a
       letter to a friend explaining what they learned about
       circuitry/magnetism/electricity that day.

Students could also create a game that utilizes their knowledge about
circuitry/magnetism/electricity and share their game with another class that did not
have a “science day”.




Teacher Lecture Materials                Additional Information                            1
Appendix 5: Cost Estimate

Circuit                 Needed per Unit Cost per Unit Needed per Ten Units       Total Cost
Peg Board (18 x 18)in                 1          $0.63                 10             $6.32
Connector Wires                     10           $5.19                100           $51.90
Knife Switch                          2          $5.98                 20           $59.80
Flash Light Bulb                      3          $4.62                 30           $46.20
C-cell Batteries                      3          $2.47                 30           $24.69
Battery Mounts                        3          $2.97                 30           $29.70
Bare Copper Wire (ft)                 8          $1.26                 80           $12.64
Totals                                         $23.13                              $231.25


Electro Magnet          Needed per Unit Cost per Unit Needed per Ten Units       Total Cost
3in Nails or bolts                    1          $0.04                 10             $0.40
Bare Copper Wire (ft)               2.5          $0.46                 25             $4.64
C-cell Batteries                      3          $2.47                 30           $24.69
Battery Mounts                        3          $2.97                 30           $29.70
Masking Tape (Rolls)                  1          $1.14                   1            $1.14
Knife Switch                          1          $2.99                 10           $29.90
Paper Clips                         10           $0.10                100             $0.97
Totals                                         $10.17                               $91.44


Electric Motor          Needed per Unit Cost per Unit Needed per Ten Units       Total Cost
Electric Motor                        1          $3.33                 10           $33.30
Totals                                           $3.33                              $33.30

Individual Experiments                                        Used in other Cost w/ reuse of
   Bulk Purchase Price Individual Cost Item Location Reusable? experiments       some parts
                        2
           8.99 per 32ft        $0.632        Lowes yes       no                       $8.99
      $5.19 per package         $0.519 Radio Shack yes        yes                     $51.90
             $2.99 each         $2.990 Radio Shack yes        yes                     $59.80
             $1.54 each         $1.540       Walmart yes      no                      $46.20
      $9.88 per package         $0.823    Sam's Club yes      yes                     $24.69
             $0.99 each         $0.990 Radio Shack yes        yes                     $29.70
     $12.63 per 80ft Coil       $0.158 McMaster-Carr yes      no                      $12.63
                $238.86


   Bulk Purchase Price Individual Cost Item Location
            $1.84 per lb        $0.040        Lowes yes       no                       $1.84
       3.71 per 20ft Coil       $0.186 McMaster-Carr yes      no                       $3.71
     $9.88 per package          $0.823    Sam's Club yes      yes
             $0.99 each         $0.990 Radio Shack yes        yes
             $6.86 per 6        $1.140    Sam's Club no       yes
             $2.99 each         $2.990 Radio Shack yes        yes
           0.97 per box         $0.010       Walmart yes      no                       $0.97
                $106.33


   Bulk Purchase Price Individual Cost Item Location
          $33.30 for 10         $3.330        Nasco yes       no                      $33.30
                $52.70                                             Total Cost:       $273.73




Teacher Lecture Materials                                Cost Estimate                         1
Student Activity Sheet                       Name _______________________________


Create Your Own Hypothesis

Circuit Boards – Create your own hypothesis (theory) about what will happen when we

connect the different items on the circuit boards. What do you think is the difference

between parallel and series?




Student Activity Sheet                        Circuit Board                              1
Student Activity Sheet                         Name _______________________________



Activity 1: Circuit Boards

1. What does it mean when an electrical current is in parallel?




2. What does it mean when an electrical current is in series?




3. What does the switch do on a circuit board?




4. Where can you find circuits in real life?




Student Activity Sheet                         Circuit Board                     2
Student Activity Sheet                  Name _______________________________



Create Your Own Hypothesis

Electro magnets – How do you think magnets are formed?




Student Activity Sheet                  Electro magnet                    1
Student Activity Sheet                      Name _______________________________



Activity 2: Electro magnet

1. How can you make your own magnet?




2. Why did our electro magnet work?




3 Put an X in front of items that were magnetic:


____ cooper wire              ____ pop can                   ____ CD


____ shiny nut                ____ shiny pan                 ____ pencil (any part?)


____ yellow ruler             ____ “silver” wire             ____ clothes pin (any part?


4 What other things did you try and were they magnetic?




Student Activity Sheet                      Electro Magnet                             2
Student Activity Sheet                     Name _______________________________



Activity 3: Motor

1. Explain how we made a motor out of the wire, battery, and magnet.




2. Motor – Why does the wire move? How does this create a motor?




Student Activity Sheet                         Motor                         1
Student Activity Sheet                       Name _______________________________

   A Letter to a Friend

   Write a letter to a friend explaining what you learned today about circuit boards,
   magnetism, and electricity. Write about the experiments that you completed and what
   you learned from the experiments.



   Dear _______________ ,




   Sincerely, _____________________

								
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