SAMPLE LAB REPORT
LAB #:
TITLE:
NAME:
DATE:
COURSE:
SEMESTER:
SECTION:
1
OHM’S LAW
A. GREAT STUDENT
1/13/2003
ELTC 200A – 1st SEMESTER ELECTRICAL
Long Beach City College
SPRING 2003
2345
PAGE 1
SAMPLE LAB REPORT
PROCEDURE:
PAGE 2
The following materials were used in this lab
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2x2 Project Board
#14 gage insulated wire
SPST Knife Switch
DPST Knife Switch
120V porcelain lamp socket
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Patch Cords for the XM Board
100W / 120V lamp
60W / 120V lamp
550W heater cone
50K ohm, 225 W resistor
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DC Ammeter 0-25amps #18
The following equipment was used in this lab
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Analog Multimeter #23
DC Milliammeter #20
The following tools were used in wiring this lab
Lineman’s Pliers, Wire Strippers, 6” Screwdriver, Staple Gun
1.
2.
3.
4.
5.
Draw the circuit diagram and have it approved by the instructor
Wire the board with the meters and lamp socket as shown in the diagram
Take cold resistance readings for all of the chosen loads. Recorded values in table 1
Obtain approval from the instructor to energize the circuit
Installed one load at a time and measured the voltage and current for each load. The
values were recorded in table #1
6. Disconnected the loads and disassembled the project board
7. Calculated the ohms and watts based on the measured amperage and voltage readings
8. Answered questions.
RECORDED DATA FROM LAB:
Cold Resistance
Voltage Reading
Amperage
Reading
120Volt 60W
Lamp
10Ω
120V
120Volt 100W
Lamp
6Ω
120V
Heater Cone 550
Watts
120V
50KΩ
120V
0.5A
0.83A
4.6A
0.002A
50K Ohm Resistor
TABLE I
Calculated Ohms
Calculated Watts
120Volt 60W
Lamp
240Ω
60W
120Volt 100W
Lamp
144Ω
100W
TABLE II
Heater Cone 550
Watts
26Ω
550W
50K Ohm Resistor
50KΩ
0.29W
SAMPLE LAB REPORT
PAGE 3
GRAPHS:
There are no graphs required for this lab
DIAGRAMS:
BYPASS
SWITCH
DPST
A
V
Fused
120VDC
from XM
Board
LOAD
UNDER
TEST
QUESTIONS:
1. This is the answer for question #1
2. This is the answer for question #2
3. This is the answer for question #3
4. This is the answer for question #4
5. This is the answer for question #5
6. This is the answer for question #6
Questions and answers both must be written.
SAMPLE LAB REPORT
PAGE 4
SUMMARY:
(A summary describes what you did in the lab)
This lab was a little confusing at first. I didn’t understand how I was supposed to come up with the
resistance while the load was connected in the circuit. At first I thought that I was supposed to
power it up and then quickly turn it off and take a resistance reading. One of my lab partners
thought that we should connect the ohmmeter across the load while it was powered. Once we
realized that we were on the wrong track and that the way to get the resistance values is through
calculations, everything started to come together. We then went on to take the required
measurements and then calculate the resistance in each case. The cold resistance of the lamp or
heater was measured with an ohmmeter out of the circuit and the hot resistance was calculated
based on voltage and current measurements.
CONCLUSION:
(A conclusion is what you learned)
This lab explained the differences between cold resistance and hot resistance. It also showed
how to calculate the hot resistance through other readings instead of directly measuring the
resistance. By knowing the volts across a load and the current through the load, we can calculate
the resistance of the load while under power. That resistance R = E/I. In the same manner, the
wattage of the device can be calculated. W = E * I
I now understand how powerful ohms law is and if I have two values, I can easily calculate the
third missing value.
END OF REPORT
The list below is a set of possible grading criteria by the lab instructor. The actual grading may vary from instructor
to instructor. Your instructor will inform you on his or her grading criteria
Item
Procedure:
Recorded Data:
Diagrams/Graphs:
Answers to Questions:
Summary:
Conclusion:
TOTAL POINTS:
100
NOTE: Reports must be done in a neat
and professional manner. Some
instructors may require that the report
be typewritten or done with a computer.
Your instructor will tell you if
handwritten reports are acceptable.
Definitions:
1. Procedure –
I.)
A series of steps taken to accomplish an end: a medical procedure; evacuation procedures.
II.)
A process or series of acts especially of a practical or mechanical nature involved in a
particular form of work
2. Summary –
I.)
Writing that presents the main points in a concise form
II.)
Presenting the substance in a condensed form; concise: a summary review
3. Conclusion –
I.)
The result or outcome of an act or process (lab experiment)
II.)
A position or opinion or judgment reached after consideration.