Ch20_Demberro

toc =Chapter 20=

Investigations 1 and 2
Objective: What is needed to make a bulb light? What will happen to bulbs when different wires are disconnected and configured? Hypothesis: A closed circuit with a power charge that is connected throughout will work. Procedure: Using the kit, find ways that light or do not light the bulb. Data:
 * Picture of Setup || Works or not ||
 * [[image:Demberrrr1.jpg width="576" height="432"]] || Works. ||
 * [[image:Photo_on_2011-10-07_at_14.29.jpg]] || Works. ||
 * [[image:Screen_shot_2011-10-20_at_10.35.02_PM.png]] || Does not work. ||
 * media type="file" key="Movie on 2011-10-14 at 22.04.mov" width="300" height="300" || None of these work when wire is disconnected. ||

Conclusion: My hypothesis was correct, whenever there was a disconnection of wires, the bulbs would not light up, showing that there had to be a closed circuit of wires. This is clearly shown in the pictures and videos in the data.

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: Metallic objects will serve as conductors and allow bulbs to light, paper and non-metallic ones will be insulators and not light the bulb. Procedure, Keep similar setup as before only have connection between bulbs have some object in between them. For example... Data: or Insulator || foil || Lit || Conductor ||
 * Picture || Object || Result || Conductor
 * [[image:Photo_on_2011-10-07_at_14.33.jpg]] || Paper clip || Lit || Conductor ||
 * [[image:Photo_on_2011-10-07_at_14.34.jpg]] || Hairpin || Lit || Conductor ||
 * [[image:Photo_on_2011-10-07_at_14.34_#2.jpg]] || Aluminum
 * [[image:Photo_on_2011-10-07_at_14.35.jpg]] || Sheet of paper || Unlit || Insulator ||
 * [[image:Photo_on_2011-10-07_at_14.36.jpg]] || Cardboard || Unlit. || Insulator. ||
 * [[image:Photo_on_2011-10-07_at_14.37.jpg]] || String || Unlit || Insulator ||

Conclusion: Hypothesis was correct. All the materials above that did not work were non-metallic, while all those that did were, showing the metallic materials will be conductors and not insulators, while the opposite is true for non-metallic ones. Also, circuits must be coming out of positive an negative end.

** 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 a material or object that allows electrons to pass freely through. You will know this if the bulbs would light due to electrons going through the filaments. It is shown in the paper clip, hairpin, and aluminum as the lights went on. Insulators, meanwhile, hinder the flow of electrons, shown when the bulbs did not turn on. When testing the string, paper, and cardboard, it became obvious that these were insulators.

Investigation 4
Objective: What parts of a socket and bulb are conductors and which are insulators? What is the conducting path through the bulb? Hypothesis: Metallic parts and filament will be conductors. Blue casings, plastic siding, top of bulb, and outside wires will be insulators. Procedure: Test out different parts of kit to see what will light the bulbs. Data

Picture - Material(s) tested - Conductor? base || No Insulator || Insulator || and filament || Yes Conductor || insulator ||
 * [[image:Screen_shot_2011-10-20_at_10.47.14_PM.png]] || Clips || Yes, Conductor ||
 * [[image:Screen_shot_2011-10-20_at_10.51.57_PM.png]] || Blue
 * [[image:Screen_shot_2011-10-20_at_10.53.31_PM.png]] || Top of bulb || No
 * [[image:Screen_shot_2011-10-20_at_10.54.38_PM.png]] || Side
 * [[image:Screen_shot_2011-10-20_at_10.56.19_PM.png]] || Side and plastic thing || No

Investigation 5
Objective: 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: You need to have a wire on each side of battery with one touching the filament, since that is where charges enter to light the bulb, and I have already proven that bulb needs complete circuit. Any way that does not have complete circuit will not work. Procedure: Test out different ways using one bulb, one wire, and one battery. Data: One side of wire touching bottom, another wire on top touching filament as metal casing is on battery. || Lit. || Same as above, only other filament is untouched by anything and other end of wire is touching metal casing. || Unlit. || Filament is touching top of battery, one end of the wire is touching metal casing. || Lit. || Both ends of wire on bottom, filament touching top. || ConUnlit. ||
 * Setup/Picture || Result ||
 * [[image:Screen_shot_2011-10-20_at_11.20.38_PM.png width="486" height="272"]]
 * [[image:Screen_shot_2011-10-20_at_11.21.45_PM.png]]
 * [[image:Screen_shot_2011-10-20_at_11.27.44_PM.png]]
 * [[image:Screen_shot_2011-10-20_at_11.29.47_PM.png]]

Conclusion: Hypothesis was correct. A complete circuit was needed with charge being able to go through filament in some manner. If circuit is not complete or one of the wires or part of battery is not touching the filament, there is no way that it can light.

Practice Set 2




Investigation 6
Objective: What does a compass tell you about what is happening in the wires of the circuit? Hypothesis: It will determine how much charge. I know this since compasses use magnets, which also have charges, so there should be a change in deflection. Procedure: Set up kit with compass under a wire. Data: (Hard to see clearly in video, tried many times, but needle in compass does indeed deflect slightly" media type="file" key="Movie on 2011-10-20 at 13.46.mov" width="300" height="300" Conclusion: Compass does in fact reveal that a charge passed through. This is evident as the compass moved as soon as the lights turned on, showing a charge had passed through.

Investigation 7
Objective: 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: Compass will deflect in other direction, meaning placement of positives and negatives do matter. Since charges mattered in electric fields, I am presuming they matter in circuits. Procedure: Repeat previous investigation, then reverse battery pack and try again. Data: Goes to my left the first setup, goes to my right the second setup. media type="file" key="Movie on 2011-10-20 at 23.59.mov" width="300" height="300" Conclusion: Setup of batteries does have effect on compass. Since compass determines direction of charge relative to positive or negative, reversing the battery pack meant that the needle would pass the other way, meaning that the charge must go positive-negative or negative-positive at all times.

Investigation 8
Objective: 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: A Genecon is some type of energy converter. It will probably reveal the positive-negative connection of a battery. Procedure: Test the abilities of a Genecon to see how it relates to circuits. Data: Cranking Genecon as it lights a bulb. media type="file" key="Movie on 2011-10-12 at 14.44.mov" width="300" height="300" media type="file" key="Movie on 2011-10-13 at 13.27.mov" width="300" height="300"

Conclusion: My hypothesis was mostly correct although it was hazy. In reality, Genecons show a change from mechanical energy (work being done to crank it) to electric energy (bulb lighting). Also, electric energy can go to mechanical energy as shown when the battery was connected to Genecon.

Reading and Explain for Schematic Diagram
What is a schematic diagram? What are the symbols for the various circuit elements? A schematic diagram is essentially a simplification of a setup in order to save time and not have to draw everything out. Here are the symbols from the reading:

Capacitance Reading and Define and Explain
What is a capacitor and how is it made? A capacitor is an object that can hold excess amounts of electrons. It can be charged through a battery where it will be holding onto excess electrons, which are then released and give off the charge as the capacitor returns to its normal self. It is made by sandwiching a conductor between two insulators and then rolling it up.

Investigation 9
Objective: What is the effect of a capacitor on a closed loop? Hypothesis: It will become charged and light bulbs for a little, and will light them again when discharged. Procedure: Use normal setup only include capacitor to circuit. Then, connect the wires in a way that circuit is in tact only battery is not included. Data: media type="file" key="Movie on 2011-10-13 at 14.02.mov" width="300" height="300" Conclusion: In a closed loop, it is possible for a capacitor to gain a temporary charge, as it lights up only for a little. With the charges all condensed and waiting to get out, the capacitor can be discharged and the electrons will be released, showed when the lights went on temporarily when wires were connected.

Investigation 10
Objective: What is origin of mobile charge? From where does the mobile charge originate during the charging and discharging process? Hypothesis: It will originate from main power source, so battery when capacitor is charging, and capacitor during discharge because capacitor has no charge at first, yet once it does and the battery is taken out, it is only logical for capacitor to take on role. Procedure: Set up so it looks like picture below: Data

Deflection || Conclusion: Since the compasses deflected same way each time, my hypothesis was correct. When charging, it goes from the presumed positive side of battery to the presumed negative. However, during discharge, the circuit runs opposite, showing the capacitor is the origin, and in order to discharge the charges must move in an opposite direction than before.
 * Location || Compass
 * A || Clockwise ||
 * B || Clockwise ||
 * C || Clockwise ||
 * D || Clockwise ||
 * E || Counterclockwise ||
 * F || Counterclockwise ||
 * G || Counterclockwise ||

Investigation 1
Objective: What effect does the type of bulb have on a capacitor during charging and discharging? Hypothesis: The bulb will have some effect on the capacitor since so far, the round bulbs have been brighter than the long ones, which points to differences to how they deal with electricity. Procedure: Charge the bulbs with the capacitor, then hook up the Genecon to the capacitor and watch it discharge on the Genecon. Data: media type="file" key="Movie on 2011-10-18 at 14.26.mov" width="300" height="300" This shows what happens when the round bulb are charged, and how it discharges on the Genecon. The latter showing how the capacitor is discharging. media type="file" key="Donotnotwork.mov" width="300" height="300" The beginning shows discharging through long bulbs. Note how much longer it lasts. Conclusion: My hypothesis was correct even if it was not properly specific. The long bulb must have more resistance, since it was lit for a much longer time than the short one. If I were to have discharged with the long ones, I can deduce that the Genecon would have spun longer as there would be a longer discharge.

What are the differences between the filaments of round and long bulbs? (Use a microscope.)
The round bulb had filaments that were much shorter, set further apart, and "fatter". The longer ones' are closer together, longer, and skinnier. These characteristics explain that the long ones have a higher resistance as there is a longer way to go to charge the filament.

How is air moving through straws analogous to charge moving through a filament?
When I blew into a wider straw, it was much easier to do so and took less effort. For the skinnier one, it was much more difficult to do so. Also, it was easier to blow out air when the straws were cut making them shorter. This mirrors the two bulbs, as the one with more resistance (meaning more difficult to light) has long and skinny filaments, while the easier one, the round one, has short and wider ones.

What is the difference between flow rate and flow speed?
Flow rate is how much charge is passing through a specific point at a specific time, while flow speed mirrors normal speed in that it is how much distance the charge covers divided by total time.

Investigation 2
Objective: How does the number of bulbs in a single loop affect the overall current and resistance in a circuit? Hypothesis: I believe there will be more resistance and less current, shown by the lights not being as bright and a smaller deflection of the compass since in our previous experiments we were scared of blowing out the bulb if there were three charges and one bulb. Procedure: Set up circuit in these following patterns. Data: Conclusion: The data shows that the more bulbs on a continuous circuit will add a greater resistance and slow down the current. This is obvious as the compass deflected less and bulbs shined less brightly with the increase in bulbs.
 * Setup || Video || Description ||
 * A || media type="file" key="One bulb.mov" width="300" height="300" || Light is fairly bright and there is a decent deflection of the compass. ||
 * B || media type="file" key="Movie on 2011-10-18 at 14.41.mov" width="300" height="300" || Light is slightly dimmer than A and compass has smaller deflection. ||
 * C || media type="file" key="Movie on 2011-10-18 at 14.42.mov" width="300" height="300" || Clearly is dimmest and has smallest deflection ||

Read and Summarize
@http://www.physicsclassroom.com/Class/circuits/ 1.What (specifically) did you read that you understand well? Describe at least 2 items fully. I understood that electric potential is the measure of voltage in a given location and the difference between high and low pressure is the route of a charge. I also understood the general workings of a circuit and how the light will be lit when there is a full, closed circuit.

2.What (specifically) did you read that made you feel little confused/unclear/shaky, but further reading helped to clarify? Describe the misconception(s) you were having as well as your new understanding. I was a little unclear about how batteries could not be rechargeable. However, I now see that that is impossible as there has to be a source charge to supply the energy, making it impossible for a battery to be rechargeable.

3.What (specifically) did you read that you don’t understand? Please word these in the form of questions. How does current relate to brightness?

4. What (specifically) did you read that you thought was pretty interesting, that you didn't know before, or can easily apply to your every day life? I now see how appliances work around the house and why energy bills are so high as the source charges have a lot of things to charge.

Investigation 3
Objective: How does the number of bulbs side-by-side affect the overall current and resistance in a circuit? Hypothesis: Since the bulbs are parallel, there will be no effect on the compass of the deflection. Procedure: Set up the bulbs in each circuit and qualitatively note the deflection of the compass. Data (used long ones): First picture: Second: Third: Brightness and deflection same.

Conclusion: My hypothesis was correct as the compass deflected the same distance each time. Also, the bulbs had the same brightness. This shows that there was no issue in terms of resistance or current when the bulbs are parallel since they each receive individual attention from the battery pack.

Investigation 4
Objective: Does adding wires in series or in parallel effect the overall resistance of the circuit? Hypothesis: The wires should not have an effect on the circuit as they have no resistance. Procedure: Set up each circuit. Data: With Circuit A being the maintained variable, Circuit B saw no change in brightness nor deflection. Circuit C saw a higher deflection, and the bulb on the far side of the additional wires became brighter and the opposite went out. Conclusion: My reasoning for my hypothesis had merit (Circuit B clearly showed that the charge passed normally through with no change) even if it was half wrong. Circuit C showed the effects of short-circuiting, as the wire sought the least amount of resistance, and found an alternative path where it only needed to go through one resisting bulb as opposed to two.

What effect do dueling battery packs have on bulb lighting and flow rate?
Analysis: This was done by Mrs. Burns in front of the class. As the number batteries on the other side increased, the light became dimmer as there was resistance from the other side, which lessoned the flow rate as the positive forces were coming in the opposite direction. However, if the battery pack had been flipped so that the positive and negative sides opposed each other, it would have been the equivalent of adding more to the original pack, and lighting and flow rate would increase.

Investigation 5
Objective: How does mixing bulbs in series affect flow rate and pressure in each part of the circuit? Hypothesis: Mixing bulbs will result in uneven flow rate and have a lopsided Procedure: Setup circuits this way. Data: media type="file" key="Movie on 2011-10-26 at 22.32.mov" width="300" height="300" Conclusion: My hypothesis was unspecific, although when the series was first set up, the long bulb was only lit. A charge is obviously going through both bulbs, but the higher resistance of the long one means there is not enough change in flow rate to light the round one. For color coding, the long bulb would see a three color jump while the round one would only see a one color jump. To describe the charging and discharging, the capacitor initially has lower resistance until it is charged. Then, the small bulb has less resistance and it lights for a little bit.

Investigation 6
Objective: What is the effect of adding another round bulb in parallel? Procedure: Set up the 3-bulb circuit in figure on the left, with a gap for a 4 th bulb to be added. Then add the 4th bulb to form the circuit in figure on the right. To switch back and forth between the two circuits, you can add the 4th bulb and its socket, and simply unscrew the 4th bulb to break the connection. Hypothesis: Nothing will happen since it will be parallel. Data: Conclusion: My hypothesis was wrong. The two middle bulbs went out, which shows there was a change in flow rate, while the two on the side were brighter than before, showing charge was still coming in. Since the ones in the middle are in the middle of two separate series, they have the same roles and see little change in electric pressure as the ones on the sides do due to the resistance after the charge passes through the side bulbs.

Investigation 7
Objective: How does the addition of another branch affect flow rate and pressure in the wires? Hypothesis: The added branches will increase resistance to the round bulb, making it less bright and lowering the flow rate and pressure. Procedure: Assemble a circuit with a 3-cell battery and a round and long bulb in series. Using a compass, measure the flow rate in wires A and B. Add a branch with a second long bulb parallel to the long bulb, but don't make the connection. Predict what will happen to the bulb brightness and flow rate when the connection is made. Repeat for a round bulb and for a connecting wire. Data: Circuit 1 Circuit 2 Circuit 3 Conclusion: My hypothesis was correct, the round bulb added on allowed for the original round to be brighter than when the long one was used as it went through less resistance. Also, the third circuit further shows the use of a path of least resistance, as the circuit is shorted and jumps only to the round one without going to the long bulb and heating up the filament.

Investigation 8
Objective: What is the effect of decreasing the resistance of right side of the circuit on: a) the flow rate through the battery; b) the pressure difference across the battery; c) brightness of the left bulb Hypothesis: Decreasing the Resistance will decrease the flow rate yet have no effect on either brightness nor pressure difference since the circuit is parallel.  Procedure: Setup the these circuits. Data:
 * Circuit A || media type="file" key="Movie on 2011-10-27 at 20.32.mov" width="300" height="300" ||  ||
 * Circuit B || media type="file" key="Movie on 2011-10-27 at 20.43.mov" width="300" height="300" ||  ||
 * Circuit C || media type="file" key="Movie on 2011-10-27 at 21.05.mov" width="300" height="300" ||  ||

Conclusion: My hypothesis was proved incorrect, as the decreasing resistance on the right side made the needle more more. The needle's displacement shows flow rate, so the flow rate increased with less resistance on the other side. Looking back at it, this makes sense, since the flow rate is split between the two parallel series and more flow is now needed for the bulb with a lot of resistance.

Practice Set: What Determines Pressure in Wires
4.