Resistors in Series and Parallel Lab
Set-up
|
V1
|
V2
|
V3
|
I1
|
I2
|
I3
|
VT
|
1
|
5.5
|
5.9
|
5.5
|
||||
2
|
3
|
3
|
3
|
3
|
6
|
||
3
|
2
|
4
|
2
|
2
|
6
|
||
4
|
5
|
5
|
6
|
6
|
6
|
||
5
|
5.5
|
5.5
|
6
|
6
|
|||
6
|
3
|
2
|
3
|
2
|
2
|
3
|
6
|
7
|
4
|
2
|
5.5
|
2
|
2
|
7
|
6
|
Calculations:
1) It = Vt/Rt = 5.5/100 = 0.055 A
Vt = (It)(Rt) = (0.055)(100) = 5.5 V
2) It = Vt/Rt = 5.5/200 = 0.0275 A
V1 = (It)(R1) = (0.0275)(100) = 2.75 V
V2 = (It)(R2) = (0.0275)(100) = 2.75 V
Vt = V2 + V1 = 2.75 + 2.75 = 5.5 V
3) It = Vt/Rt = 5.5/320 = 0.0172 A
V1 = (It)(R1) = (0.0172)(100) = 1.72 V
V2 = (It)(R2) = (0.0172)(220) = 3.78 V
Vt = V2 + V1 = 3.78 + 1.72 = 5.5 V
4) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/100 = 0.055 A
V1 = (It)(R1) = (0.055)(100) = 5.5 V
V2 = (It)(R2) = (0.055)(100) = 5.5 V
Vt = V2 + V1 = 5.5 V
5) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/220 = 0.025 A
V1 = (I1)(R1) = (0.055)(100) = 5.5 V
V2 = (I2)(R2) = (0.025)(220) = 5.5 V
Vt = V2 + V1 = 5.5 V
6) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/220 = 0.025 A
It = Vt/Rt = 5.5/168.75 = 0.033 A
1/Req = (1/R1 + 1/R2) + 100 = (1/100 + 1/220) + 100 = 168.75 Ohms
V1 = (It)(R1) = (0.033)(68.75) = 2.268 V
V2 = (It)(R2) = (0.033)(100) = 3.3 V
Vt = V2 + V1 = 5.5 V
7) I1 = V1/R1 = 5.5/220 = 0.025 A
I2 = V2/R2 = 5.5/100 = 0.055 A
It = Vt/Rt = 5.5/76.2 = 0.0722 A
R3 = R1 + R2 = 100 + 220 = 320
R4 = 100
1/Req = 1/R3 + 1/R4 = 1/320 + 1/100 = 76.2 Ohms
V1 = (It)(R1) = (0.025)(220) = 5.5 V
V2 = (It)(R2) = (0.055)(100) = 5.5 V
Vt = V2 + V1 = 5.5 V
1) It = Vt/Rt = 5.5/100 = 0.055 A
Vt = (It)(Rt) = (0.055)(100) = 5.5 V
2) It = Vt/Rt = 5.5/200 = 0.0275 A
V1 = (It)(R1) = (0.0275)(100) = 2.75 V
V2 = (It)(R2) = (0.0275)(100) = 2.75 V
Vt = V2 + V1 = 2.75 + 2.75 = 5.5 V
3) It = Vt/Rt = 5.5/320 = 0.0172 A
V1 = (It)(R1) = (0.0172)(100) = 1.72 V
V2 = (It)(R2) = (0.0172)(220) = 3.78 V
Vt = V2 + V1 = 3.78 + 1.72 = 5.5 V
4) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/100 = 0.055 A
V1 = (It)(R1) = (0.055)(100) = 5.5 V
V2 = (It)(R2) = (0.055)(100) = 5.5 V
Vt = V2 + V1 = 5.5 V
5) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/220 = 0.025 A
V1 = (I1)(R1) = (0.055)(100) = 5.5 V
V2 = (I2)(R2) = (0.025)(220) = 5.5 V
Vt = V2 + V1 = 5.5 V
6) I1 = V1/R1 = 5.5/100 = 0.055 A
I2 = V2/R2 = 5.5/220 = 0.025 A
It = Vt/Rt = 5.5/168.75 = 0.033 A
1/Req = (1/R1 + 1/R2) + 100 = (1/100 + 1/220) + 100 = 168.75 Ohms
V1 = (It)(R1) = (0.033)(68.75) = 2.268 V
V2 = (It)(R2) = (0.033)(100) = 3.3 V
Vt = V2 + V1 = 5.5 V
7) I1 = V1/R1 = 5.5/220 = 0.025 A
I2 = V2/R2 = 5.5/100 = 0.055 A
It = Vt/Rt = 5.5/76.2 = 0.0722 A
R3 = R1 + R2 = 100 + 220 = 320
R4 = 100
1/Req = 1/R3 + 1/R4 = 1/320 + 1/100 = 76.2 Ohms
V1 = (It)(R1) = (0.025)(220) = 5.5 V
V2 = (It)(R2) = (0.055)(100) = 5.5 V
Vt = V2 + V1 = 5.5 V
Conclusion
- evaluate the differences between theoretical and experimental values. The agreement is expected not to be perfect, but you should determine if the agreement is reasonable
The theoretical values are the values that in theory you "should" get, if you plug the values into an equation. The experimental values are those we actually got doing the lab. In theory, the theoretical and experimental values should be the same, but this will almost never happen due to human error. In our case, the experimental values was generally a bit less than the theoretical ones.
- make some general statements of what you learned about circuits in series, parallel, series-parallel, and parallel-series networks.
I learned that during a series circuit, the voltage will be constant throughout. And in a parallel circuit, the voltage will evenly split between the two parallels. I also learned that in series-parallel and parallel-series circuits, the voltage can differ between the resistors, they aren't necessarily the same for each resistor.
- discuss other sources of error such as the effect
of adding a voltmeter and ammeter in a circuit and not including the internal
resistance of the battery in your calculations.
We found it very difficult to construct the more complex circuits, and then even more difficult to add the Voltmeter and Ammeter to those to find their readings. There was also much possible human error by the placing of the metal clips. It made a difference of where on the resistor you placed the clips. It was also very possible to misread the Voltmeter and Ammeter. There was much potential human error in this lab.
