sac 4 - folio of electronics practical activities
TRANSCRIPT
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
1/13
VCE Unit 3: SAC 4 Outcome 3.2
1
SAC 4 Annotated Folio of Practical Activities for Electronics
Outcome 2
NAME ___________________________ ID ____________ Score _____ / 20
Conditions for the task
You will complete three practical activities:
Ohmic and Non-Ohmic Resistors in Series and Parallel
You will work in pairs or small group to collect the results in 9.05
You will work individually to analyse your results and write your evaluation and
conclusion in 5.04
Date: 7 May 2012
Investigation of Diodes
You will work in pairs or small group to collect the results for Parts A & B in 9.05
You will work individually to complete Part C in 5.04
You will work individually to analyse your results and write your conclusion in 5.04
Date: 14 May 2012
The Amplifier Simulation Investigation
You will work individually to complete the investigation in 5.04
You will work individually to write your conclusion in 5.04
Date: 21 May 2012
You must record all results individually in this Booklet.
The teacher will collect the Booklet on completion of each activity.
All work will be completed in class time.
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
2/13
VCE Unit 3: SAC 4 Outcome 3.2
2
Ohmic & Non-Ohmic Resistors in Series and Parallel Circuits
AIM:
To measure current and voltage for an Ohmic and Non-Ohmic resistor individually and when
combined in series and parallel.
To recognise how Current vs Voltage graphs differ for Ohmic and Non-Ohmic resistors To use Raw Data and Excel to find the relationship between current and voltage for the
Ohmic and Non-Ohmic resistor.
To compare the actual relationship between current and voltage measured by experiment for
series and parallel circuits with the relationship predicted by theory from Processed Data.
THEORY:
Symbols: Voltage V Current I
Resistance R = V/I, Ohmic Resistance Ro (constant), Non-Ohmic Resistance Rn(changes
with current)
Resistance of Ro and Rn in series Rs Resistance of Ro and Rn in parallel R//
For an Ohmic resistor a graph of Voltage, V vs Current, I is a straight line through the origin
with gradient equal to the constant resistance, R.
A light globe is a Non-Ohmic resistor whose resistance increases with current.
Resistors combined in Series and Parallel
APPARATUS:
DC power supply, 15 resistor (Ohmic resistor), rheostat (variable resistor), 12 V 36 W light bulb
(Non-Ohmic resistor), ammeter, voltmeter, connecting wires.
METHOD:
Four different loads will be placed in the circuit shown:
Load 1. Ro = 15 , Ohmic resistor
Load 2. Rn = Light Globe, Non-Ohmic
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
3/13
VCE Unit 3: SAC 4 Outcome 3.2
3
Load 3. Rs = Ro in series with Rn (Ohmic and Non-Ohmic resistors in series)
Load 4. R// = Ro in parallel with Rn (Ohmic and Non-Ohmic resistors in parallel)
1. Connect the power supply, rheostat, ammeter, voltmeter and Load 1 as shown in the circuitdiagram.
To avoid damaging the multimeters, use their largest scales initially then change to the relevant
scale.2. Adjust the rheostat to vary the voltage across the load and record 10 widely spaced values of
voltage and corresponding current in the Raw Data Table.
Note: the light bulb will not glow for low currents
3. Repeat 1. 3. for Loads 2, 3 and 4
Raw Data Table
Ohmic/Non-Ohmic Circuits
Ohmic Non-Ohmic Series (Actual) Parallel (Actual)
V(V) I (A) V(V) I (A) V(V) I (A) V(V) I (A)
Analysis4. Copy your data from the Data Table into Excel
5. Plot a Scatter Plot of Current vs Voltage for the Ohmic and Non-Ohmic resistances on the one setof axes.
For the Ohmic resistor insert a linear trend line through the origin and show the equationusing correct symbols and significant figures
Write the equation here:
Equation 1: I = ____V For the Non- Ohmic resistor insert a power trend line and show the equation using correct
symbols and significant figures
Write the equation here:
Equation 2: I = ____V____
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
4/13
VCE Unit 3: SAC 4 Outcome 3.2
4
6. Plot a ScatterPlot of Voltage vs Current for the Ohmic and Non-Ohmic resistances on the one setof axes.
For the Ohmic resistor insert a linear trend line through the origin and show the equationusing correct symbols and significant figures
Write the equation here:
Equation 3: V = ______ I What value does this equation predict fro Ro?
Ro = _____ For the Non- Ohmic resistor insert a power trend line and show the equation using correct
symbols and significant figures
Write the equation here:
Equation 4: V = ____I____
7. Complete the Processed Data Table in Excel. Use: Equation 3 to complete Column 2 Equation 4 to complete Column 3 Equation 1 to complete Column 6 Equation 2 to complete Column 7
Processed Data Table
Series (Predicted) Parallel (Predicted)
I (A) Vo Vn Vs = Vo + Vn (V) V (V) Io In I// = Io + In (A)
0.02 1.00
0.04 2.00
0.06 3.00
0.08 4.00
0.10 5.00
0.12 6.00
0.14 7.00
0.16 8.00
0.18 9.00
0.20
10.0
0
8. Complete Columns 4 and 8.
9. Plot on the one set of axes, a Scatter Plot of Current vs Voltage for Series (Actual) from the RawData Table and Series (Predicted) from the Processed Data Table.
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
5/13
VCE Unit 3: SAC 4 Outcome 3.2
5
10.Plot on the one set of axes, a Scatter Plot of Current vs Voltage for Parallel (Actual) from theRaw Data Table and Parallel (Predicted) from the Processed Data Table.
Conclusion and EvaluationA statement of how Ohmic and Non-Ohmic resistors differ and how the graphs plotted in points 9. and 10.
support the theory for resistors in series and parallel.Was the experiment successful? How could it be improved? What are the sources of error?
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
6/13
VCE Unit 3: SAC 4 Outcome 3.2
6
Investigation of DIODES
AIM:
1. To measure the forward and reverse resistance of diodes
2. To use Excel to plot the current-voltage characteristics of a diode
3. To use simulations to look at diode operation and rectification.
Theory:
A diode allows an electric current to flow in one direction, but blocks it in the opposite direction.
Circuits that require current flow in only one direction only include one or more diodes.
Diodes are based on semiconductor p-n junctions. In a p-n diode, conventional current can flow from
the p-type side (the positive anode) to the n-type side (the negative cathode), but not in the
opposite direction.
The voltage drop across a normal silicon diode at rated currents when forward biased is 0.6 to 0.7
volts. This value is the diode turn-on voltage. For other diode types it has a different value. eg light-
emitting diodes (LEDs) can be 1.4 V or more.
A typical graph of Current vs Voltage for a diode is
shown.
Equipment:
DC Power Supply
2 Digital Multimeters
Board with1k resistor and diode
Rheostat
Leads
METHOD and DATA COLLECTION:
Part A: The Multimeter and Diode Polarity
1. Multimeter:
a. Connect the red lead to the V. .mA jack and the black lead to the COM jack.
b. The multimeter can measure voltage when connected in parallel with the circuit
element and with the rotary switch set to the left voltage band. Start with the
range at the highest range position and then reduce by turning the dial anti-
clockwise.
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
7/13
VCE Unit 3: SAC 4 Outcome 3.2
7
c. The multimeter can measure current when connected in series with the circuit
element and with the rotary switch set to the right current band.
Start with the range at the highest range position and then reduce by turning the
dial clockwise.
2. Diode Operating Voltage:
a. Use a multimeter to measure the voltage of the diode. Turn the multimeter dialto the special diode setting.
Connect the black negative lead to the bar end of the diode and the positive red
lead to the other end of the diode. The diode voltage for forward biased is
shown.
Vdiode = ____________V
b. Next reverse the polarity of the multimeter leads so that the positive lead is now
connected to the bar end. The diode is now reverse biased.
The reading should show 1 indicating that current does not flow in the reverse
direction.
c. Compare the forward and reverse voltages. Explain how this will affect current
flow in a circuit.
Part B: Diode Current-Voltage Characteristics
1. To examine how the current through a diode varies as the potential difference across it is
changed, connect the circuit as shown below with the diode forward biased.a. 1st connect the power supply to the rheostat using the 2 connections at the base.
b. Next connect the lead from the 1000 to the top connection.
c. Finally insert the 2 multimeters to measure the current and voltage for the diode.
1000 ohm
VR
Vsupply
1 k
2. Vary the rheostat setting so that the potential difference, Vdiode across the diode from 0.0
Volts to the maximum possible. For each setting, record the voltage and current I in the
table below.
3. Also record the uncertainty in voltage and current in the table heading by observing anyfluctuations of the meter.
12V
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
8/13
VCE Unit 3: SAC 4 Outcome 3.2
8
Raw Data Table
Forward biased
Vdiode (Volts)
Vdiode =
I (milliamps)
I =
Vdiode (Volts)
Vdiode =
I (milliamps)
I =
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
9/13
VCE Unit 3: SAC 4 Outcome 3.2
9
ANALYSIS:
4. Enter your results into an Excel Spreadsheet and create a Scatterplot of Current (mA) vs
Vdiode (Volts).
a. Your Scatterplot must show a Exponetial trendline with the Equation.
b. Show x and y error bars.
c. Use all the correct conventions.5. How does the maximum value you found for Vdiode compare with the value of Vdiode found
using the multi-meter?
6. How do values you found for Vdiode by the 2 methods compare with the expected range of
0.6 0.7?
Part C: Simulation
1. Diode:
a. Go to http://www.falstad.com/circuit/e-diodevar.htmland complete the following
Table.
b. Go to:http://www.falstad.com/circuit/e-diodecurve.htmland observe the Current
vs Voltage across the diode for a time varying input signal.
c. Half-wave rectifier - Go to :http://www.falstad.com/circuit/e-rectify.html
i. Sketch the circuit.
ii. What is the input Voltage from the ac power supply? = _____ V
iii. What is the voltage across this diode? Vdiode = _______ V
Vdiode (Volt) 0 0.2 0.3 0.4 0.5 0.6 0.62 0.64 0.66 0.68 0.70 0.72
I
(indicate if pA, A
or mA)
http://www.falstad.com/circuit/e-diodevar.htmlhttp://www.falstad.com/circuit/e-diodevar.htmlhttp://www.falstad.com/circuit/e-diodecurve.htmlhttp://www.falstad.com/circuit/e-diodecurve.htmlhttp://www.falstad.com/circuit/e-diodecurve.htmlhttp://www.falstad.com/circuit/e-rectify.htmlhttp://www.falstad.com/circuit/e-rectify.htmlhttp://www.falstad.com/circuit/e-rectify.htmlhttp://www.falstad.com/circuit/e-rectify.htmlhttp://www.falstad.com/circuit/e-diodecurve.htmlhttp://www.falstad.com/circuit/e-diodevar.html -
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
10/13
VCE Unit 3: SAC 4 Outcome 3.2
10
iv. On the axes below sketch the input signal (green) from the power supply
and the output signal (yellow) across the 640 resistor. Annotate your
graph to indicate if current is flowing or not at different times.
CONCLUSION:Summarise what you have learnt about the diode. Use the words forward bias, reverse bias and diode turn-on
voltage. State and compare the diode turn-on voltages you measured.
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
11/13
VCE Unit 3: SAC 4 Outcome 3.2
11
The Amplifier Simulation
Applet:http://ngsir.netfirms.com/englishhtm/Amplifier.htm
1) Open the Applet and use the default values for all variables unless told otherwise. You canreturn to the default settings by refreshing..
2) What is the voltage gain of the amplifier?
AV =
3) This is an inverting amplifier. What does that mean?
4) With an input signal with vin = 0.4 V (input amplitude = 0.2 V), what is vout?(nb: means from peak to peak and we use lower case v for ac signals and upper case V for dc
signals)
vout =V
5) Increase the input signal to vin = 0.8 V (input amplitude = 0.4 V).a) What is vout?
vout = 8 V
b) Describe and sketch the output signal.
6) Refresh and make RC = 1.8 k
7) What is the voltage gain of the amplifier?
AV =
8) With an input signal with vin = 0.4 V, what is vout?
vout = V
9) With an input signal with vin = 0.8 V.a) What is vout?
vout = V
http://ngsir.netfirms.com/englishhtm/Amplifier.htmhttp://ngsir.netfirms.com/englishhtm/Amplifier.htmhttp://ngsir.netfirms.com/englishhtm/Amplifier.htmhttp://ngsir.netfirms.com/englishhtm/Amplifier.htm -
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
12/13
VCE Unit 3: SAC 4 Outcome 3.2
12
b) Describe and sketch the output signal.
10)Refresh and make R1:R2 = 6
11)With an input signal with vin = 0.4 V, what is vout?
vout = V
12)Increase the input signal to vin = 1.0 V.a) What is vout?
vout = V
b) Describe and sketch the output signal.
Conclusion:Summarise what you have learnt about amplifiers. Use the words voltage gain, inverting amplifier,
distortion and clipping in your answer.
-
7/31/2019 SAC 4 - Folio of Electronics Practical Activities
13/13
VCE Unit 3: SAC 4 Outcome 3.2
13
Assessment Sheet: SAC 4 Annotated Folio of Practical Activities for
Electronics
Name: _________________________ ID _____________ Score _______ /20
Comments:
Criterion Excellent (5) Good (4) OK (3) Poor/Bad
Raw & Processed
DataA record of your
observations and
measurements and values
determined from the raw
data
Sufficient raw data has been collected.
Data or observations are presented in
well organised, correct ruled or
computer generated tables.
Data has been correctly processed when
required
Correct units and significant figures are
given.
Calculated values are presented.
Error are recorded (when applicable)
One or twoitems required
for excellent
are missing.
About half ofthe items
required for
excellent
have been
completed
Most of the itemsrequired for
excellent are missing.
2
Data that of anotherstudent and this is
acknowledged
1
No data recorded or
data that of another
student and this is
not acknowledged
0
AnalysisManipulations of data to
get what you are after;
include graphs in this
section. Show sample of
each type of calculation.
Include calculations of
absolute or relative error if
required.
Correct graphs are presented. Graphs are used correctly to obtain
required information
All applicable formulas are listed.
All symbols are defined.
A sample of each type of calculation is
shown.
Setting out is neat, correct and easy to
follow.
All calculated values are clearly
identified with units
Analysis shows understanding
One or twoitems required
for excellent
are missing.
About half ofthe items
required for
excellent
have been
completed
Most of the itemsrequired for
excellent are missing.
2
Calculations identical
to those of another
student
1
No calculationsshown
0
QuestionsAnswer all questions
included on your instruction
sheet.
All questions have been answered
All answers are correct
Answers are in clear English and/or are
illustrated with a clear diagram. Answered are neatly presented.
Answers show understanding
One or the
items required
for excellent is
missing.
Two of the
items
required for
excellent aremissing.
Most of the items
required for
excellent are missing.
2 Answers identical to
those of another
student
1
Questions are notanswered
0
Conclusion &
EvaluationThis is a briefsummary of
your results and conclusions
drawn from them.
State any equations you
found.
State any values you
calculated (with uncertainty
if applicable).
State the percentage
difference from the
expected value if possible.
How could the experiment
be improved?
A brief summary of results is given.
Equations and values determined from
the results are given.
An objective, scientific conclusion
relating theory to the results, using
proper scientific language, is given.
Sources of error are identified Suggestions for improving the
experiment are given.
Mistakes are acknowledged.
One or the
items required
for excellent is
missing.
Two of the
items
required for
excellent are
missing.
Most of the items
required for
excellent are missing.
2
Conclusion identicalto that of another
student1
No conclusion given
0