ELEG 2011
ELECTIRCAL CUIRCIT LABORATORY
FALL 2010
LABORATORY REPORT ON
Lab 6
Statistical Application To Electronic Circuits And
Ohms Law
Conducted On
March 14, 2011
Submitted By:
James Jones, Terrance Tutt, Jasmine Smith, Christen
Roberts
On
March 21, 2011
To
Dr. C. L. Tolliver
Table of Contents
I Abstract
II Introduction
i Purpose
ii Scope
iii Apparatus
iv Procedure
III Discussion
IV Results
V Conclusion
VI References
VII Appendix
Abstract
In this lab we took measured values of voltages, currents, and resistances using the equipment
provided in the lab. We learned to be proficient in analysis in electrical circuits based on the
voltage, current, and resistance values we measured in the lab with the proper equipment. We
verified all measured using basic circuit and network theory laws.
Introduction
Purpose:
Measure voltage, current, and resistance using the multimeters provided in the lab
Proficiency in statistical analysis of electrical circuits based on resistance, current and
voltage measurement
Validate theoretically calculated results using basic network laws
Scope:
The aim of this lab is to prepare the student for more in depth tasks and projects by introduction
to basic laws, building and equipment.
Apparatus:
Mulitmeter, DC Power Supply, Ten 180 resistors, Ten 470 resistors
Procedure:
Part A
1. Measure the resistance value of each of the two group of ten resistors given to your group
using any of the two instruments in procedure 1 and 2.
2. Record your measured value in the Table 1.
Table 1: Resistance Measurement
R=
0.47 k
R=
0.18 k
Tolerance
(%)
Measurement Measurement
R
1
R
1
5 .464 k .178 k
R
2
R
2
5 .461 k .179 k
R
3
R
3
5 .462 k .179 k
R
4
R
4
5 .461 k .178 k
R
5
R
5
5 .464 k .178 k
R
6
R
6
5 .463 k .179 k
R
7
R
7
5 .464 k .179 k
R
8
R
8
5 .463 k .180 k
R
9
R
9
5 .462 k .179 k
R
10
R
10
5 .462 k .178 k
3. From the data you recorded in Table 1, calculate the mean, the median and the variance.
Record your calculated variance in Table 2.
Table 2: Variance
Part B
4. Connect the circuit in Figure 1.
R1
180
R2
470
Vs
2 V
Variance (R=0.47 k) Variance (R=0.18 k)
4.44 x 10
-8
5.44 x 10
-8
1.11 x 10
-7
1 x 10
-8
4.44 x 10
-7
5.44 x 10
-8
1 x 10
-6
5.44 x 10
-8
4.44 x 10
-8
5.44 x 10
-8
1.11 x 10
-7
1 x 10
-8
4.44 x 10
-8
1 x 10
-8
1.11 x 10
-8
1.87 x 10
-7
4.44 x 10
-7
1 x 10
-8
4.44 x 10
-7
5.44 x 10
-8
V
s
(V) V
L
(V) I(mA)
Desired Real Measured Measured Caluculated
2 2.2 1.5 3.35 A 3 mA
3 3.2 2.3 4.87 A 4 mA
4 4.3 3.1 6.54 A 6 mA
5 5.4 3.9 8.22 A 7 mA
6 6.4 4.6 9.74 A 9 mA
7 7.5 5.4 11.43 A 10 mA
5. Adjust the supply voltage as shown in Table 3, measure the corresponding current I
flowing in the circuit and the voltage V
L
across the 470 resistor and record your
readings in Table 3.
Table 3
6. Plot the graph of the measured voltage V
L
and the measured current I
V
L
(V)
Discussion
0
2
4
6
8
10
12
14
16
18
0 2 4 6 8 10
I(A)
I(A)
8 8.5 6.1 12.95 A 123 mA
9 9.6 6.9 14.64 A 138 mA
10 10.7 7.7 16.34 A 153 mA
Patrick Butler:
In this experiment, we statistically analyzed resistance, current, and voltage measurements of an
electrical circuit. In part A of the lab, we started off by measuring each of the 20 resistors (ten
180 and ten 470) given in the experiment. With the data we recorded, we then calculated the
variance of each resistor using the variance equation specified within the lab. In Part B of the lab,
we used one of each resistor to build a simple electrical circuit in series. Using the variable
supply and the digital multimeter provided, we measured current I flowing in the circuit and the
voltage V
L
across the 470 resistor at different desired voltage outputs. Using these
measurements, we plotted a graph of the voltages V
L
and the currents I.
Karan Chawla:
It was a fun and easy lab and none of us had any confusion while performing the
experiment and also while doing the lab report. In this experiment, we had to measure the
voltage, current, and resistance using a multimeter. We had one issue while we were measuring
the current but we quickly realized what we were doing wrong and found the best way to resolve
our issue. The problem that we faced was our current measurements were not coming out to be
right but we figured that it wasnt coming out to be right because we did not connect the
ammeter in series with the circuit components. This error caused a short circuit and changed the
circuit parameters. This lab really helped me learn the basic foundation of electrical engineering
and will definitely help me become a successful engineer in the future.
Christopher St. Julian
In this lab we found that the statistical analysis of the current, voltage and resistance was
fairly straightforward in terms of calculations. We measured the resistance across the given
resistors and using the tolerance we were able to find the mean, median and variance values.
These values were then used to calculate the remaining voltage and current results using Ohm's
law. This lab was very helpful by showing us how to understand basic circuits using statistical
analysis. We encountered few errors with this lab. The only major setback once again, was the
inconsistency in our current measurements and calculations. We soon found that these
discrepancies were as a result of wire resistances. Soon after we addressed this problem by re
measuring and modifying our results accordingly. This type of analysis in this lab was very
unique and is a very versatile tool in many electrical engineering applications.
Results
The variance measurements that we recorded for each resistor were very small, ranging from
4.44 x10
-8
to 1 x10
-6
for the 470 resistor and 5.44 x10
-8
to 1 x10
-7
for the 180 resistor. Our
measurements for voltage V
L
in the circuit was a bit smaller then our desired voltages. On the
other hand, the measurements we obtained for current I were much larger then our theoretical
calculations. When we plotted the data of the voltage and current measurements that we found,
we were able to see a positive correlation between the voltage V
L
and the current I.
Conclusion
In this lab, we learned to apply statistical principles as well as fundamental electrical laws and
rules to measure various components. We now have a better understanding of how to apply this
knowledge to any labs and circuits that we may encounter in the future.
References
N/A
Appendix
Description of procedure and apparatus:
The DC Power Supply and Digital Multimeter were used for the measurement of the current,
voltage and resistance.
