Also, the higher the voltage in the cell, the more energy it gives to the electrons pushed out. To produce a higher potential difference, several lamps should be connected ni series. I also know from knowledge that whilst moving around a circuit, from one battery to the lamp, the sum of the voltages across the circuit must be equal to the potential difference across the battery.
Procedure
Testing the Current
- Form a circuit as shown in Circuit 1 on the sheet attached. The battery must be set at 6V.
- As shown with the letters, insert the ammeter.
- Record the results.
- Repeat steps 1-3 for Circuit 2, 3, and 4.
Testing the Voltage
- Form a circuit as shown in Circuit 1 on the sheet attached. The battery must be at 6V.
- As shown with numbers, insert the voltmeter from one point to another to get the potential difference.
- You must measure the potential difference with at least five points shown in the diagram.
- Record results.
- Repeat steps 1-4 using Circuit 2,3,4, and the additional 5.
Results (on attached sheet)
Analysis
As we can see in our first, second and third circuit, the current of the circuit stays the same through out.
Current
Circuit 1: As seen in this circuit, the current is approximately the same differing by .01 amps. It is probable that our results may not be accurate as we know from information that the current should remain constant through out the circuit. It is likely that our readings may not have been completely accurate and furthermore the ammeter does not show us thousands of decimals! We had also observed that the lamp was very bright.
Circuit 2: In this circuit, the current had stayed constant like predicted in my hypothesis. The current had remained .033 amps. However, the light had been less bright than the circuit before. The reason for this will be given in my conclusion.
Circuit 3: Like the previous circuit, the current in this one is also unvarying. The current with this circuit that had three light bulbs had been .027 amps. Nevertheless, the lamps had become even less bright and quite dim.
Circuit 4: My hypothesis for this circuit had been partly correct. It is assumable that the lamps had been of same size, resistance etc as the current had divided into two to give enough electrons going through each lamp. The current at the beginning and end of the circuit was .065, and the current in the bottom half, where it splits was .032. Obviously, two times this does not add up to .065 but to .064. It should be noted that there was definitely a source of error as once again the ammeter may have not been completely accurate to the hundredth decimal. Conversely, my hypothesis had also been partly incorrect as the lamps had been very bright. I had assumed them to get quite dim as there were two bulbs in the circuit. The reason for this was explored and will be explained later on.
I had also observed that the currents had added up to approximately .1 amps, leaving room for error. I had not mentioned this in my hypothesis as it was noticed after that the more lamps in the circuit, the lower the current.
Voltage (PD)
Circuit 1: From the beginning of the end of the circuit, it is clearly shown that the voltage was used up as there was a potential difference of 6.01 volts. However, it is not possible that there could be more difference than the actual amount of volts put into the circuit. This leads to the conclusion that there was clearly a source of error. Going from one point of a wire to another without crossing a light bulb, the difference had .01; therefore, no voltage was given off in the wire and would only be given off to the lamp. As followed, a big difference was seen when the voltmeter was put on to measure the voltage before and after crossing the lamp as all of it was used up. Our meter read 6.07V; once again, there would definitely have been a problem of accuracy. The lamps were really bright in this circuit.
Circuit 2: Once again, the difference between the beginning and end of the circuit had been approximately 6.00V due to the fact that it was used up in lighting the lamps. There had been a changed voltage difference from 2-3 and from 3-4. This was probably because the lamps had not been of equal size and resistance needing more voltage or less voltage to light the bulb. As seen once again, close to nothing is used in the wires. As with the circuit before, the lights had gotten dimmer than the one before because it was a series circuit.
Circuit 3: Sources of error may have occurred in this circuit too as not everything adds up equally. The difference from one part of the wire to another crossing the bulb had also been approximately the same which leads to the conclusion that the lamps must be of equal resistance. The lamps of this series were extremely dim as the voltage was to be distributed.
Circuit 4: In this parallel circuit, the lamps had been extremely bright; as bright as they were in circuit 1. The voltage had seemed to be the same in the separate branches as the same with Circuit 5. The lights were also bright, but the lights that were in the same series were dimmer than the lamp and this was the same as with the series circuit.
Conclusion
From our results above, we are able to interpret the reason being for many of the things that happened. From our aim, we were able to interpret the data gathered.
From the information gathered and the observations made, we are able to interpret that in a series circuit that a single path is created for electron flow as mentioned above. This is due to the fact of the current given out is the same as the current going back to the battery. That of which leads me to Ohm’s Law which states that the current anywhere along the circuit is equivalent to the voltage supplied by the source divided by the total resistance. Also, the potential difference is decreased over each resistance, as it is used to light the lamp. As I predicted in my hypothesis, in a series circuit, the brightness of the lamp decreases as more lamps are added to the circuit. This is due to the distribution of power needed to lamp each light.
Moreover, it was noticeable that in a parallel circuit, branches are formed providing separate paths for the flow of electrons, obviously. However, the current also separates as I mentioned in my hypothesis but since the current braches, a break in one or more of those pathways does not disturb the flow in the other path. Each device connects the same two points of the circuit; therefore, the voltage is the same across each device. This was the reason why the light bulbs had been equally as light as the voltage had stayed the same, and was not obliged to be distributed like in a series circuit. In a parallel circuit, the voltage is present in each branch. In a series circuit, the voltage had to be equally distributed through out the circuit, however, when it wasn’t, it was assumable that one lamp had more/less resistance than another.
This lab would have been more efficient and spared time if we had put together one circuit and measured both the current and the potential difference at the same time in place of doing them separately. Furthermore, it should definitely been taken into consideration that the ammeters and voltmeters may not have been 100% accurate as our results show due to running out of battery etc. A change in the tools may have caused differentiating results as we had not been constant through out the experiment. Additionally, taking a reading 4 to 5 times would have made results much more precise but due to time limitations this was not possible.
