Labs
Measuring Voltage
Objective
To accurately measure the voltage of
ð individual cells and batteries
ð cells and batteries in series.
Safety Precautions in General
ð Pay attention and follow all instructions.
ð Do not sit on any of the tables - some stools are provided.
ð Do not open any cabinets or use any equipment unless directed to do so.
ð Playing, engaging in any unsafe acts, and not following instructions in the lab will not be
tolerated. Students will be removed from the lab and reported for all violations.
Safety Precautions Specific to This Lab
ð Voltmeters are always connected to the circuit or across the voltage source in parallel.
ð Make sure that the
Ø positive lead of the voltage source is always connected to the positive terminal (RED) of
the voltmeter
Ø negative lead is connected to the negative terminal (BLACK) of the voltmeter.
Equipment for this lab - per team
1 digital multimeter
1 type D cell and 6 type AA cells
Lab Requirements
Measuring
Voltage of Individual Cells and Cells in Series
Use the digital voltmeter to measure the voltage of the type D cell and 3 of the type AA cells. Create a neat and well-organized data sheet and record the readings.
Use the digital voltmeter to measure the voltage, in series, of the 3 type AA cells you measured individually above. Use tape to connect them.
Turn In
Lab report and initialed data sheet in accordance with standard format for all lab reports.
Using the
breadboard
Address
each of the following requirements in your report
Each team has been given
three 56 kW
resistors, a breadboard, a 9 V battery with connector, two clip-on probe
inserts, and a box of precut wires.
Part a:
Measuring resistance using the ohmmeter
The
resistor is removed from circuit to calculate (power supply not connected)
1.
Verification of resistors using color code
Using the
color code in your notebook, verify that the resistors are as stated above.
Do this by
converting the color code. Show your work in the report.
Determine the
tolerance of the resistors.
2.
Measurement of resistors and verification that they are within tolerance
Assemble the
3 resistors in a series configuration on the breadboard and measure
the resistance of each.
State this resistance in your report.
State the resistance
for each and whether it is within tolerance.
3.
Total resistance
Calculate the
total resistance.
Measure the
resistance.
Include the
values in your report and discuss any differences.
Part b:
Measuring voltage drop using the voltmeter
The
connection is in parallel with the circuit (power supply connected - only
after connections have been made)
1. Attach
the 9 V power supply (only after circuit has been assembled)
2.
Calculate the voltage drop that should occur across each resistor.
3.
Measure the voltage drop across each resistor and explain any differences.
Part c:
Measuring current using the ammeter
The
ammeter must be placed in series with the circuit (power supply connected -
after connections have been made)
1.
Calculate the voltage of the battery
2.
Calculate the current that should be flowing through the circuit.
3.
Measure the current that is flowing through the circuit.
4. Compare the two currents and explain any differences.
Objectives
1. To
measure the total voltage supplied by individual batteries, batteries in
series, and
batteries in
parallel using the breadboard.
2. To
measure the voltage across resistors in parallel using the breadboard.
3.
Current calculation and measurement.
Requirement
for All Labs
ð
All measurements for all labs must be included in your report. Place
them in a neat
and
appropriately labeled table. The completed raw data sheet must be initialed
by
me prior to
leaving the lab. It must be attached to your final lab report.
ð
Teams work together but all lab reports must be submitted
individually.
ð
All lab reports must be typed with name, date, and lab number at the
top.
ð
The specific setup used to accomplish all requirements must be
clearly described.
For example,
clearly describe the specific connections used in measuring the voltage
of batteries
in series and parallel (+ connection goes where, negative connection
goes where),
and the configuration of the resistors
ð
Draw and clearly label a circuit diagram using the software provided
for all circuit
configurations. Include the batteries and the resistors.
Equipment
Each team will have access to three 56 kW resistors, a breadboard, two 9 V batteries, 2 battery connectors, a multimeter, and a box of precut wires.
Procedure
ð
Measure the voltage of each of the two 9 volt batteries.
ð
Connect the batteries in parallel and measure the voltage provided.
ð
Connect the batteries in series in measure the voltage provided.
ð
Construct a parallel circuit consisting of the series connection for
the batteries
with each of
the three resistors in a parallel configuration.
ð
Measure the voltage across each resistor.
ð
Calculate the equivalent resistance of the 3 resistors in parallel
(use the resistor
values you
obtained last lab when you measured the resistance of each resistor - or
measure them
again).
ð
Using the equivalent resistance, calculate the current in the
circuit.
ð
Can you measure the current? If so, measure it and compare it to the
above
calculated
value. If not, state the reason.
Format for All Labs
Use the exact paragraph
titles as shown below
1. Problem statement:
Clear statement of what you are trying to do
2. Hypothesis: Suggested
explanation of the observed phenomenon
3. Approach: Short summary
of how you plan to solve the problem
4. Data recorded: Data
obtained from the experiment – turn in your initialed data sheet.
5. Analysis of the data:
What the data means
6. Conclusion:
a. What conclusions do you draw from the above analysis.
b. What are possible sources of error.
c. What are some
suggestions for future work in this area.