Ch20+Part+1_RabinR

= Chapter 20: Basic Electric Circuits (Part 1) = toc http://www.physicsclassroom.com/Class/circuits/

Investigation 1
What is needed to make a bulb light? HYPOTHESIS: To make a bulb light, there must be circuits forming a closed loop through conducting material carrying the charge from a source to the bulb. SAMPLE DATA: CONCLUSION: My hypothesis was correct however minor details are necessary to make my statements completely accurate. To make a bulb light, there must be a source of charge (in this case a battery). There also must be two separate circuits each attached to either the positive or negative end of the source charge. The circuits must then form a closed loop with no breaks to the bulb, each circuit attaching to either the tip or threaded section (in this case the circuits attached to the clips of the sockets which each connected to either the tip or the threaded section thus acting as conductors).

Investigation 2
What will happen to Bulbs 1 and 2 when you disconnect the wires of the configuration below at the various labeled points? HYPOTHESIS: If the wires of the configuration above disconnect at any of the various labeled points the bulbs will not light. This is proven through investigation 1 which concludes that there must be a closed loop without breaks between the source charge and the bulb for a bulb to light. Therefore, if the wires are disconnected at any points labeled above, the closed loop will be broken and the bulbs will not light. SAMPLE DATA: CONCLUSION: My hypothesis was correct. In this investigation when the wires were disconnected at each labeled point the bulbs did not light proving that a closed loop without breaks is required from the source charge to the bulb in order for a bulb to light.

Investigation 3
What type of object, when inserted into the space labeled "something" in the loop shown below, will allow the bulbs to light? HYPOTHESIS: Just as the clips and plates of the socket must be made of metal in order for the wires attached to the clips to fully form a closed loop with the tip and the threaded section, any object inserted into the space labeled "something" in the loop shown above must be made of metal as well in order for the bulb to light. SAMPLE DATA: CONCLUSION: My hypothesis was very accurate. All the metallic objects used in the investigation allowed the bulb to light while none of the non-metallic objects used allowed the bulb to light.

DEFINE and EXPLAIN
What is a conductor and what is an insulator? How do you know? How can you test this using our loop configuration? A conductor is any object or material that allows electrons to flow through easily and thus produces, or conducts, electricity. An insulator, on the other hand, is any object or material that does not allow electrons to flow easily and thus does not produce, or conduct electricity. In the previous investigation, various objects or materials were placed in the space labeled "something" to explain the difference between a conductor and an insulator. The objects (paperclip, metal ring, and yellow gold) that resulted in a lit bulb can be recognized as conductors because the electrons flowed freely through the object completing the closed loop, while the objects (paper and string) that resulted in an unlit bulb can be recognized as insulators because each did not allow electrons to flow easily creating a break in the loop. The scenarios used with the conductors produced light while the those performed with the insulators did not.

Investigation 4
What parts of the socket and bulb are conductors and which are insulators? What is the conducting path through the bulb? HYPOTHESIS: The clips and plates of the socket are conductors because they are both made of metallic materials. Metal has proven to be a conducting material in previous investigations. The base of the socket is an insulator because it is made of plastic which is not a metal and will not allow the bulb to light. The tip, threaded section, and filament of the bulb are conductors because they are made of metallic materials and as stated before, metals have proven to be a conducting material. The glass and black ring are insulators because they are not made of metallic materials and thus will not light the bulb. The conducting path through the bulb must be through the tip, up from one side of the filament to the other, leading into the threaded section because these are the conducting materials that make up the bulb. SAMPLE DATA: CONCLUSION: My hypothesis was correct. The clips, plates, tip, threaded section, and filament all allowed the bulb to light when acting as a part of the closed loop and thus are all conductors. The base, glass, and black ring all did not allow the bulb to light when acting as a part of the closed loop and thus are all insulators. Due to the proven conductors, the conducting path must be: clips -> plates -> tip -> filament -> threaded section -> plates -> clips.
 * For all scenarios, screw bulb into socket securely. Ensure the tip of the bulb is touching the plate of the socket. Attack one wire to positive end of battery and attach another wire to negative end of battery. Attach opposite sides of each wire to specified part of socket and bulb.

Practice Set 1
The CCP

Investigation 5
How can you light a bulb using one battery, one bulb, and one wire ONLY? How many different correct ways can you do this? What DIDN'T work, and why? HYPOTHESIS: The only way to light a bulb using one battery, one bulb, and one wire ONLY is by in some assortment connecting both ends of the battery and both the threaded section and tip of the bulb with the metallic parts of the wire. SAMPLE DATA: CONCLUSION: My hypothesis was correct. The metallic parts of the wires had to in some combination touch the positive and negative sides of the battery as well as the threaded section and tip of the bulb. I could only light my bulb with two different combinations however, I am unaware if there are more variations of this scenario. I also tried to light the bulb using other parts of the battery and bulb however none of the attempted parts were conductors and therefore did not light the bulb.

Practice Set 2
Basic Circuits

DEFINE
What is a circuit? A circuit is a closed loop with no breaks between a source of charge and the receiving object. For example, in our previous investigations the batteries acted as the source of charge while the wires created the closed loop to the sockets and the bulbs, the objects receiving the electrons.

Investigation 6
What does a compass tell you about what is happening in the wires of the circuit? HYPOTHESIS: The current of charge flowing through the wires will cause the compass to deflect. CONCLUSION: My hypothesis was correct. As soon as the circuit was completed and closed, a current ran through the wire over the compass making an electric field. The compass lies in the electric field and therefore is affected by the force of the electric field. Thus, the compass deflected.

Investigation 7
What effect does reversing the battery pack have on the compass deflection? What does this mean about the role of the battery in the circuit? HYPOTHESIS: Every time a battery pack is reversed the compass will deflect in the opposite direction. CONCLUSION: My hypothesis was correct however there are specific directions the compass will deflect pending on the battery connection. If the compass lays under the wire connected to the negative end of the battery, the compass will deflect counter-clockwise. if the compass lays under the wire connected to the positive end of the battery, the compass will deflect clockwise. This means that the flow of charges originates from only one end of the battery.

Practice Set 3
Wires

Investigation 8
What is a Genecon and how does it work? What does it tell you about the role of the battery in the circuit and why? HYPOTHESIS: By turning the handle, the Genecon will become an energy source to flow through the close circuit, the bulb will light. SAMPLE DATA: media type="file" key="Movie on 2011-10-13 at 13.24.mov" media type="file" key="Movie on 2011-10-13 at 13.22.mov" CONCLUSION: My hypothesis was correct. The Genecon acts as the battery in the previous investigations, it pumps the electron converting mechanical energy into potential energy and thus a current of charge flows through the circuits and the bulbs light. This tells us that the battery does not actually provide the electrons for the circuit, it only provides the energy to pump the charge through the circuit.

DEFINE and EXPLAIN
What is a schematic diagram? What are the symbols for the various circuit elements? A schematic diagram is a simple, standard design for drawing circuit components. The symbols can be seen through the chart displayed below.

Practice Set 4
Schematics

DEFINE and EXPLAIN
What is a capacitor and how is it made? A capacitor acts as a storing device for energy. It is made up of two sides of conducting material with a layer in the middle of insulating material. Because of the insulating material, a capacitor breaks up the closed loop of a circuit but allows the energy to be stored for later use. Placing wax paper in between two metal materials, is an easy way to create a capacitor.



Investigation 9
What is the effect of a capicitor on a closed loop? HYPOTHESIS: Charging an air capacitor will allow the bulb to light without the use of batteries in the circuit. SAMPLE DATA: media type="file" key="Movie on 2011-10-13 at 14.01.mov" width="300" height="300" CONCLUSION: My hypothesis was correct. To charge an air capacitor the circuit must be complete. The bulbs will light and eventually die out. When the bulbs die out this means the air capacitor is charged. Once it is charged, by taking the two wires connected to the battery packs and connecting them together, the bulbs will light for a significant amount of time and eventually die out.

Investigation 10
What is origin of mobile charge? From where does the mobile charge originate during the charging and discharging process? HYPOTHESIS:The mobile charge originates from the battery in the charging process and the mobile charge originates from the air capacitor in the discharging process. PROCEDURE: By placing a compass under the wire in each of the set ups above, the results of the motion of the compass will prove the hypothesis. SAMPLE DATA: CONCLUSION: My hypothesis was correct! When the compass is placed under the wire in the charging process the compass moves clockwise whereas when the compass is placed under the compass in the discharging process the compass moves counter-clockwise. This proves that the charge originates from opposite sides of the circuits, each place where the batteries and the circuits are lying.

Practice Set 5
Electrical Energy

Practice Set 6
Capacitance