Mission to Planet Earth Name:
Date: Period:
3L1a: Multimeter Measurements Activity
1. Measuring Ohms (W) of resistance:
Labeled Value Measured Value
470 K W
100 K W
10 K W
1 K W
100 W
2. Measuring Voltage (V) in a battery
Labeled Value Measured Value
1.5 V (120 to 121)
3.0 V (119 to 120)
4.5 V (119 to 121)
6.0 V (121 to 123 with 119 J 124)
9.0 V ( )
3. Measuring Current (A) in a single resistor circuit, using 3V battery: Calculate all values before measuring. Show your calculations below. Be careful of units.
R Calculated mA Measured mA
470 W
1 K W
4.7 K W
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L1b: Series Resistor Circuit
Req = R1 + R2 + R3
1. Calculate Req. Fill in the table above. Show your calculations here.
2. Calculate I (through the mA meter). Fill in the table above. Show your calculations here. Be careful of units.
3. Calculate V1 (voltage across R1), V2, V3, VT (sum of V1 + V2 + V3). Fill in the table above. Show your calculations here.
4. Set up the circuit and measure each of the above currents and voltages. Fill in the table above. Be careful of units.
5. Explain why there are differences between your calculated values and what you measured.
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L1c: Parallel Resistor Circuit
1/Req = 1/R1 + 1/R2 + 1/R3
1. Calculate Req. Fill in the table above. Show your calculations here.
2. Calculate I (through the mA meter), I1, I2, I3 (through each resistor), & IT (total of Fill in the table above. Show your calculations here. Be careful of units.
3. What are V1, V2, and V3? How do you know?
4. Set up the circuit and measure each of the above currents and voltages. Fill in the table above.
5. Explain why there are differences between your calculated values and what you measured.
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L1d: Combined Resistor Circuit
Req = R1 + R2 + R3
1/Req = 1/R1 + 1/R2 + 1/R3
1. Calculate Req. (Two steps) Fill in the table above.
Show your calculations here.
2. Calculate I (through the mA meter), I1, I2, I3 (through each resistor). Fill in the table above. Show your calculations here. Be careful of units.
3. Calculate V1 (voltage across R1), V2, V3. Fill in the table above. Show your calculations here.
4. Set up the circuit and measure each of the above currents and voltages. Fill in the table above.
5. Explain why there are differences between your calculated values and what you measured.
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth
3L2: Energy Efficient Building Experiment Design
Purpose:
To design an experiment to test student written hypotheses about building materials and methods as they apply to energy efficiency. This is based upon the experiment outlined on page 704-5 in the Earth Science textbook.
Definitions:
Experiment: A plan for a set of observations designed to extend our knowledge about how the world works.
Hypothesis: This is a prediction of what might be observed given a set of conditions. It must be clear, well-defined, and falsifiable. In other words, there must be a test that could prove this prediction unequivocally wrong.
Test Protocol: This is where the test for a hypothesis is defined. It is a plan with a set of conditions, procedures, and measurements that is designed to provide either confidence that the hypothesis is true or proof that it is false. If it cannot provide these results then it is a poor test of this hypothesis. Usually, a test fails because it did not exclude the effects of other factors than the ones being tested.
Result: A set of measurements or direct observations should have specific meaning. Generally, one should be able to enumerate all possible results and attribute the pass or fail of the hypothesis to each possible result before performing the test.
Conclusion: This is where the experimenter reports on the experiment. Did the hypothesis fail or did it pass. What did it prove?
What additional tests of the hypothesis should be planned next.
Experiment Report
Title page
Phase 1: Design
1. Purpose of Project
2. Design Issues (at least 15)
3. Hypotheses (at least 5)
4. Chosen hypothesis
5. Test Protocol
6. Possible results (observations) and meaning of each.
Approval
Phase 2: Construct and Test
1. Construct building
2. perform test
Phase 3: Analyze data & write report
1. Graph measurements
2. Answer both sections of questions 1-5 and 1-3
3. Conclusion: What have you proved?
Work in groups. Every member collaborates on every part or document. Each document will be signed by the member who actually wrote it, will start on a fresh page, and will be titled as above.
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L3: Light and the Inverse Square Law
Let’s measure the irradiance from an incandescent light bulb at several distances, check the rated luminance of the bulb, and predict the measurement at another distance.
Definitions of Light measurements:
FV = Luminous Flux of the source (lumens)
ER = Irradiance of an object illuminated by LR at a distance d (W/m2 )
ER = FV / (e d2) = FV (1/d2) / e
Visible efficacy of an Incandescent light: e =17 lm / W
We know several things will affect our measurements:
· light intensity (nearness and brightness of a lamp),
· angle of incidence (does it face the light), and
· shadows (is anything blocking the light).
We need to be sure that only the first effect (nearness) is allowed during our experiment.
The current produced by our solar panel then should be a measure of (be proportional to) the irradiance falling upon it.
1. Choose a light bulb and install it into a lamp facing horizontally across your table. Place a meter stick on the table below it and starting with the zero-end directly below the bulb so that it measure the distance from the bulb.
Light bulb wattage = W
Light bulb luminous flux = Lumens
Write the Luminous Flux in the data table under FV.
2. Find and mark the following three locations that are:
0.25m and 1.0 m and 1.5 m from the bulb. Write these distances in the data table in column d for the first 3 rows.
a. Calculate the Inverse Square distance 1/d2 and complete this column.
b. Calculate Irradiance, ER for each location in data table. Refer to formula above and the example given in lecture. Show your calculations.
3. Use the multimeter to measure the current from the solar panel at each of these three locations. Be sure to keep the panel fully facing the lamp, room lights off, with no shadows, and no glare from any books or papers laying on the table.
Refer to the schematic diagram in figure 1.
Fill in the Current column labeled I in the data table.
Figure 1: Current
4. Graph your data accurately
· Plot each point precisely
· Change the axis scales if necessary.
5. Fit a straight line
· Using a ruler, draw a straight line that most closely contains all of your three data points as well as the graph origin.
3L-AlternativeEnergy 2/7/2010
Loc# / Luminous Flux
Fv
(lumens) / Distance
d
(m) / Inverse Square
1/d2
(1/m2) / Irradiance
ER
(W/m2) / Current
I
(mA)
1
2
3
This section to be completed in step 7
Predicted
Measured
6. Calculate the slope, S, of this best-fit line.
· Measure a point on this best-fit line near the upper right corner of your graph
Irradiance of the selected point = W/m2
Current at this point = mA
Slope (rise/run) S = W/m2 /mA
7. Fill in data table for your prediction at a new location of 0.50 m from the bulb.
a. Fill in Luminous flux, Distance, Inverse Square, and Irradiance.
b. Predict the expected Current. I = ER / S. Show your calculation.
8. Measure the current at this location, complete the table, and compare.
How close was your prediction? Why or Why not?
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L4: Solar Panel Characteristics
Let’s measure the power output by a solar panel. We know several things will affect it:
· light intensity (nearness and brightness of a lamp),
· angle of incidence (does it face the light), and
· shadows (is anything blocking the light).
However, the more current we use from the panel the lower the voltage.
Since P = IV the power output will vary with the current and this will vary with the voltage.
Ohm’s law tells us that we can change the current by connecting different resistors across the panel’s terminals.
We want to find the optimum current that will give us the maximum power.
1. Place the solar panel a fixed distance from the lamp and make sure it squarely faces the lamp with no shadows in the way. Don’t let any of this change during your experiment.
Light bulb wattage = W
Light bulb luminous flux = Lumens
Distance from light bulb to panel = cm
2. Locate the set of resistors. Identify each resistor’s value by the color bands and fill in the following table in order from smallest to largest resistance.
Resistor / color bands / value / Resistor / color bands / valueR1 / R5
R2 / R6
R3 / R7
R4 / R8
3. Use the multimeter to measure the voltage across the solar cell terminals while connecting at least 10 different resistances including none (shorted wire), and each resistor across the terminals.
Refer to the schematic diagram in figure 1.
Fill in the Resistance and Voltage columns of the data table.
4. Use the multimeter to measure the current from the solar panel while connecting resistors in exactly the same manner and order as in step 3.
Refer to the schematic diagram in figure 2.
Fill in the Current column of the data table.
Figure 1: Voltage Figure 2: Current
5. Calculate the power output of the Solar panel for each resistance load. P = IV.
Fill in the Power column of the Data Table.
Resistance(Ω) / Voltage
(V) / Current
(mA) / Power
(mW)
shorted
(wired directly, no resistor)
open (no circuit)
6. Graph your data.
On a separate sheet of graph paper:
· Label the sheet: “Solar panel Characteristics”, add your name and date
· You will create two separate graphs each will cover half the page.
· Graph one will have Current on the vertical axis. Graph two will have Power on the vertical axis and both will have Voltage on the horizontal.
· Look at the range of data in your table and choose your scales for all three axes.
· Draw and label all axes with names, units, and values
· Draw all 10 points on both graphs and connect them with a curve.
· Staple this graph to the back of this sheet.
7. Locate the maximum power output.
Maximum Power = mW
Voltage at Max Power = V
Current at Max Power = mA
Resistance at Max Power = Ω
8. On an attached sheet, write the purpose and your conclusion for this experiment.
3L-AlternativeEnergy 2/7/2010
Mission to Planet Earth Name:
Date: Period:
3L5: Hydrogen Fuel Cell
Let’s measure the rate of production of Hydrogen and Oxygen gas generated by the fuel cell and solar panel. We know that several things will affect the fuel cell:
· It must be filled with water (no bubbles in the intake)
· The water must be pure (distilled)
· The solar panel must have a constant power output
We know that several things will affect the solar panel:
· light intensity (nearness and brightness of a lamp),
· angle of incidence (does it face the light), and
· shadows (is anything blocking the light).
1. Set the solar panel up just like you did in experiment 3L3. Use the same lamp and distance. Don’t let any of this change during your experiment.
Light bulb wattage = W
Light bulb luminous flux = Lumens
Distance from light bulb to panel = cm
2. Assemble the fuel cell according to directions and fill it with distilled water.
3. Turn on the light and start timing the reaction. Measure the volume of both gases every minute for 15 minutes. Record this in the data table. While this step is in progress, proceed with steps 4 and 5.
4. Measure the voltage.
Use the multimeter to measure the voltage across the solar cell terminals while generating gases.
Voltage during generation = V
5. Measure the Current.
Turn off the lamp (and stop the timer while the lamp is off). Disconnect the wire from the Solar Panel to the fuel cell at the fuel cell and connect the multimeter instead. Be sure the multimeter is set to measure current in mA. through the solar panel while generating gases. Turn on the lamp and the timer. Record your measurement.
Voltage during generation = V
3L-AlternativeEnergy 2/7/2010
Time(minutes) / Volume of H2
(ml) / Volume of O2
(ml)
6. Graph your data.
On a separate sheet of graph paper:
· Label the sheet: “Fuel Cell Generation Rate”, add your name and date
· You will create one graph with two lines (oxygen and hydrogen).