ELECTRICAL AND ELECTRONICS ENGINEERING

DEPARTMENT

Basic Electronics for Mechanical Engineers

ACTIVITY 1: Oscilloscope and Function Generator Operations

1.1 Program Outcomes (POs) Addressed by the Activity

b. ability to design and conduct fieldworks, as well as to analyze and interpret data
k. ability to use techniques, skills, and modern engineering tools necessary for
engineering practice

1.2 Activity’s Intended Learning Outcomes (AILOs)

At the end of this activity, the student shall be able to:
a. identify the different parts of an oscilloscope and a function generator
b. explain the functions of each part of an oscilloscope and function generator
c. calculate the peak value and the period of an input signal based on the display of the
oscilloscope
d. evaluate the precision of the experiment conducted

1.3 Objectives of the Activity

The objective of this activity is to:
a. be familiar with the different parts and functions of oscilloscope and function
generator.

1.4 Principle of the Activity

Oscilloscope

The oscilloscope is the most important instrument available to the practicing technician
or engineer. It permits the visual display of a signal that can reveal a range of information
regarding the operating characteristics of a circuit or system that is not available with a standard
multimeter. At first glance, the instrument may appear complex and difficult to master. Be
assured, however, that once the function of each section of the oscilloscope is explained and
understood and the system is used throughout a set of experiments, your expertise with this
important toll will develop quite rapidly.
In addition to the display of a signal, it can also be used to measure the average value,
rms value, frequency and period of a sinusoidal or nonsinusoidal signal. The screen is divided
into centimeter divisions in the vertical and horizontal directions. The vertical sensitivity is

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 1

provided (or set) in t time (s/cm). If a particular signal occupies six (6) vertical centimeters and
the vertical sensitivity is 5mV/cm, the magnitude of the signal can be determined from the
following equation:

Signal voltage (unknown) = voltage sensitivity (V/cm) x deflection (cm)

V=(5mV/cm)x(6cm)=30mV (1.1)

If one cycle of the same signal occupies 8 cm on the horizontal scale with a horizontal
sensitivity of 5 μs/cm, the period and frequency of the signal can be determined using the
following equations:

Periodof waveform=horizontalsensitivity(s/cm)xdeflection(cm) (1.2)

T = (5 μs/cm) x (8 cm) = 40 μs
And
f = 1/T = 1/40 μs = 25 kHz

Function Generator

The function generator is a supply that typically provides sinusoidal, square-wave, and a
triangular waveform for a range of frequencies and amplitudes. Although the frequency of the
function generator can be set by the dial position and appropriate multiplier, the oscilloscope can
be used to precisely set the output frequency. The scope can also be used to set the amplitude of
the function generator since most function generators simply have an amplitude control with no
level indicators. Both the scope and function generator are built to withstand some abuse, so do
not be afraid to try various combinations of dial settings to fully develop your abilities with this
laboratory experiment. In addition, if you are working in a group, do not let one person perform
all the experimental work. You must spend the time in the laboratory, so why not learn how to
use the equipment properly and develop the skills that you will need when you see graduation
approaching and a job appears that will require a firm understanding of how to use the
oscilloscope and function generator.

1.5 Materials/Equipment

Instruments:

1 unit Oscilloscope

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 2

 1 unit DMM

Supplies:
1 unit Function Generator

1.6 Circuit Diagrams / Figures / Source Codes (if Applicable)

1.7 Procedure/s

Part 1. The Oscilloscope

The instructor will provide a brief description of the various sections of the oscilloscope
and function generator.

Part 2. The Function Generator

Set-up

a. Turn on the oscilloscope and adjust the necessary controls to establish a clear, bright,
horizontal line across the center of the screen. Do not be afraid to adjust the various
controls to see their effects on the display.
b. Connect the function generator to one vertical channel of the oscilloscope and set the
output of the generator to a 1000 Hz sinusoidal waveform.
c. Set the vertical sensitivity of the scope to 1 V/m and adjust the amplitude control of the
function generator to establish a 4V peak-to-peak (p-p) sinusoidal waveform on the
screen.

Horizontal Sensitivity

d. Determine the period of the 1000 Hz sinusoidal waveform in ms using the equation T =
1/f. Show all work for each part of the experiment. Be neat!

(calculated) T = 1 ms

e. Set the horizontal sensitivity of the scope to 0.2 ms/cm. Using the results of Part 2 (d),
calculate and predict the number of horizontal divisions required to properly display one
full cycle of the 1000 Hz signal.

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 3

 (calculated) Number of divisions = 5 div

Use the oscilloscope and measure the number of required divisions and insert below.

(measured) Number of divisions = 5 div

How does the result compare to the calculated number of divisions?

f. Change the horizontal sensitivity of the oscilloscope to 0.5 ms/cm without touching any
part of the controls of the function generator. Using the results of Part 2(d) how many
horizontal divisions will now be required to display one full cycle of the 1000 Hz signal?

(calculated) Number of divisions = 2 div

Using the oscilloscope, measure the number of required divisions and insert below.

(measured) Number of divisions = 2 div

How does the result compare to the calculated number of divisions?

g. Change the horizontal sensitivity of the oscilloscope to 1 ms/cm without touching any
part of the controls of the function generator. Using the results of Part 2(d), how many
horizontal divisions will now be required to display one full cycle of the 1000 Hz signal?

(calculated) Number of divisions = 1 div

Using the oscilloscope, measure the number of required divisions and insert below.

(measured) Number of divisions = 1 div

How does the result compare to the calculated number of divisions?

It is the same with the measured division.

h. What was the effect on the appearance of the sinusoidal waveform as the horizontal
sensitivity was changed from 0.2 ms/cm to 0.5 ms/cm and finally to 1 ms/cm?

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 4

 It takes 5 boxes to portray the whole wave with a 0.2ms/cm. It took 2 boxes to display the
whole wave as the horizontal sensitivity increased from 0.2 to 0.5 ms/cm. Change the
from 0.5 to 1 ms/cm by repeating the process. It simply required 1 box to depict the whole
wave at 1 ms/cm. The sensitivity of each box grew as more waves passed through it.

Did the frequency of the signal on the screen change with each horizontal sensitivity?
No, the frequency remained constant with each horizontal sensitivity.

What conclusion can you draw from the results regarding the effect of the chosen
horizontal sensitivity on the signal output of the function generator?

A more sensitive frequency readout is achieved by increasing the horizontal sensitivity.

i. Given a sinusoidal waveform on the screen, review the procedure to determine the
frequency of the pattern. In other words, develop a sequence of steps to calculate the
frequency of a sinusoidal waveform appearing on the screen of an oscilloscope.

Vertical Sensitivity

j. Do not touch the controls of the function generator but return the sensitivity of the scope
to 0.2 ms/cm and change the vertical sensitivity to 2 V/cm. Using this sensitivity,
calculate the peak-to-peak value of the sinusoidal waveform on the screen by first
counting the number of vertical divisions between peak values and multiplying the
sensitivity.

(calculated) Peak-to-peak value = 4 Vp-p

k. Change the vertical sensitivity of the oscilloscope to 0.5 V/cm and repeat Part 2(j).

(calculated) Peak-to-peak value = 4 Vp-p

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 5

 l. What was the effect on the appearance of the sinusoidal signal with each change in the
vertical sensitivity? What conclusion can you draw from the results regarding the effect
of changing the vertical sensitivity on the output signal of the function generator?

The sinusoidal signal occupied the full screen as a result of the change in the vertical
sensitivity. The peak amplitude does not change when changing the vertical sensitivity on
the output signal of the function generator.

m. Can the peak-to-peak output voltage of a function generator be set without the aid of an
auxiliary instrument such as an oscilloscope or DMM? Explain.

Yes, because the function generator only accepts peak voltage, the peak voltage can be
calculated by multiplying the peak-to-peak value by two, allowing it to be entered directly
into the function generator without the aid of an auxiliary instrument.

Part 3. Exercises

a. Make all the necessary adjustments to clearly display a 5000 Hz, 6 Vp-p sinusoidal signal
on the oscilloscope. Establish the zero-volt line at the center of the screen. Record the
chosen sensitivities.
Vertical Sensitivity: 1 V/div
Horizontal Sensitivity: 50μs/div

Draw the waveform on the Fig. 1.1 carefully noting the required number of horizontal
and vertical divisions. Add vertical and horizontal dimensions to the waveform using the
sensitivities listed above.
Calculate the period of the waveform on the screen using the resulting number of
required horizontal divisions for a full cycle.

(calculated) T = 200μs

b. Repeat Part 3(a) for a 200 Hz, 0.8 Vp-p sinusoidal waveform on Fig. 1.2.

Vertical sensitivity = 1V/div

Horizontal Sensitivity = 1ms/div

(Calculated) T = 5ms
ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 6
 c. Repeat Part 3(a) for a 100 kHz, 4 Vp-p square wave on Fig. 1.3. Note that a square wave
is called for.
Vertical sensitivity = 1V/div
Horizontal Sensitivity = 1μs/div

(Calculated) T = 10μs

Part 4. Effect of DC Levels

a. Re-establish the 1 kHz, 4 Vp-p sinusoidal waveform on the screen. Calculate the
effective value of the sinusoidal waveform.
(calculated) Vrms = 1.414 V

b. Disconnect the function generator from the scope and measure the effective (rms) value
of the output of the function generator using the digital meter.

(measured) Vrms = 1.35 V

c. Determine the magnitude of the percent difference between the calculated and measured
levels using the following equation:

%Difference =

%Difference = 4.53%

d. Reconnect the function generator to the scope with the 1 kHz, 4 Vp-p signal and switch
the AC-GND-DC coupling switch of the vertical channel to GND. What is the effect?

The amplitude of the wave becomes zero and remains constant throughout the screen when
the vertical channel's coupling switch from AC-GND-DC is changed to GND.

Why? How can this scope function be used?

Because the scope function focuses the graph on the screen at the origin, it can be used to
find distinct values that occur over time and the vertical position must be adjusted correctly.

e. Now move the AC-GND-DC coupling switch to the AC position. What is the effect on
the screen display? Why?

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 7

 The graph will illustrate the waveform of the signal according to the peak-peak voltage
time period of the wave when the vertical channel's coupling switch is changed
from AC-GND-DC to AC. The signal was restored and the AC mode displays the AC
component of the input signal.

f. Finally, move the AC-GND-DC coupling switch to the DC position. What is the effect in
the screen display (if any)? Why?

Because there is no DC, no changes were discovered. In other words, there is no movement
in the graph.

1.8 Activity Report

Section: 1-A Date Performed: 02/06/2022

Course Code: CPE0011L Date Submitted:
Course Title: Fundamentals of Electronic Circuits (Lab)
Instructor: Engr. Arnel Nuesca
Group No.: Activity No.: 1

Group Members: Signature:

1. Rupert Lance Y. Sobreviñas

2.
3.
4.
5.

1.8.1 Data and Results

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR
 Peak voltage at 3V. 4 Division per cycle. T=200μs

Figure 1.1

Peak voltage at 4V. 5 Divisions per cycle. T=5ms

Figure 1.2

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 9

 Peak voltage at 2V. 10 Divisions per cycle. T=10μs

Figure 1.3

1.8.2 Calculations
II.
D. T = 1/f = 1/1000Hz =1ms
E. Period of waveform = (0.2 ms/cm) (0.001) = 200ms
No. of divs = 1ms(1div/0.2ms) = 5 divs
F. No. of divs = 1ms(1div/0.5ms) = 2 divs
G. No. of divs = 1ms(1div/1ms) = 1 div
J. P-P value = 2div (2V/div) = 4Vp-p
K. (0.5V/cm) (8) = 4Vp-p

III.
A. T = 4div (50μs/div) = 200μs
B. T = 5div (1ms/div) = 1ms
C. T = 10div (10μs/div) = 10μs

IV.
A. Vrms = 4v (1/2) (0.707) = 1.414V
B. Difference (%) = ((1.414-1.35)/1.414) (100) = 4.53%
 1.8.3 Observations (if applicable)
For what I observed is that whenever the time base was adjusted, the oscilloscope's
signal wave took longer or shorter to complete one wave cycle, and the volt peak
was modified, the signal waves have made the vertical divisions increased or
decreased. The appearances on graph of the wave changes when you adjusted the
horizontal or vertical sensitivity.

1.8.4 Conclusion/s
As a result, the researcher concluded that the higher the frequency, the more waves
there will be before one complete division. The researcher can set the value of the
peak-to-peak value on the function generator, and if the value of volt peak-peak
changes, the time it will take to complete a full cycle will be determined by the
vertical and horizontal sensitivity of the wave.

1.8.5 Rating (include Rubric)

ACTIVITY 1: FAMILIARIZATION WITH OSCILLOSCOPE AND FUNCTION GENERATOR 10

 ELECTRICAL AND ELECTRONICS ENGINEERING
DEPARTMENT

Basic Electronics for Mechanical Engineers

ACTIVITY 2: Diode Characteristics

2.1 Program Outcomes (POs) Addressed by the Activity

b. ability to design and conduct fieldworks, as well as to analyze and interpret data

2.2 Activity’s Intended Learning Outcomes (AILOs)

At the end of this activity, the student shall be able to:
a. identify the diode’s threshold voltage
b. calculate the diode’s AC and DC resistances
c. evaluate the precision of the experiment conducted

2.3 Objectives of the Activity

The objective of this activity is to:
a. be familiar with the characteristics of a silicon diode

2.4 Principle of the Activity

Most modern day digital multimeters can be used to determine the condition of a diode.
They have a scale denoted by a diode symbol that will indicate the condition of a diode in the
forward- and reverse-bias regions. If connected to establish a forward-bias condition, the meter
will display the forward voltage across the diode at a current level typically in the neighbourhood
of 2 mA. If connected to establish a reverse-bias condition, an “OL” should appear on the display
to support the open-circuit approximation frequently applied to this region. If the meter does not
have diode-checking capability the condition of the diode can also be checked by obtaining some
measure of the resistance level in the forward and reverse-bias regions. Both techniques for
checking diode will be introduced in the first part of the experiment.
The characteristics of a silicon or germanium diode have the general shape shown in Fig.
2.1. Note the change in scale for both the vertical and horizontal axes. In the reverse-biased
region, the reverse saturation currents are fairly constant from 0V to the zener potential. In the
forward-bias region the current increases quite rapidly with increasing diode voltage. Note that
the curve is rising almost vertically at a forward-biased voltage of less than 1V. The forward-

ACTIVITY 2: DIODE CHARACTERISTICS 1

biased diode current will be limited solely by the network in which the diode is connected or by
the maximum current or power rating of the diode.
The “firing potential” or threshold voltage is determined by extending a straight line
(dashed lines of Fig. 2.1) tangent to the curves until it hits the horizontal axis. The intersection
with the VD axis will determine the threshold voltage VT.
The DC or static resistance of a diode at any point on the characteristics is determined by
the ratio of the diode voltage at any point, divided by the diode current. That is,

ohms (2.1)

The AC resistance at a particular diode current or voltage can be determined using a

tangent line drawn as shown in Fig. 2.2. The resulting voltage (∆V) and current (∆I) deviations
can then be determined and the following equation applied.

ohms (2.2)

It can be shown though differential calculus that the AC resistance of a diode in the
vertical-rise section of the characteristics is given by

ohms (2.3)

For levels of current at and below the knee of the curve, the AC resistance of a silicon
diode is better approximated by

ohms (2.4)

2.5 Materials/Equipment

Instruments:
1 unit DMM

Components:
Resistors:
1 piece 1 kΩ
1 piece 1 MΩ

ACTIVITY 2: DIODE CHARACTERISTICS 2

 Diodes:
1 piece Silicon

Supplies:
1 unit DC Power Supply

2.6 Circuit Diagrams / Figures / Source Codes (if Applicable)

Figure 2.1. Silicon and germanium diode characteristics

Figure 2.2

ACTIVITY 2: DIODE CHARACTERISTICS 3

 Figure 2.3. Diode Testing

Figure 2.4

Figure 2.6

2.7 Procedure/s

Part 1. Diode Test

Diode Testing Scale

ACTIVITY 2: DIODE CHARACTERISTICS 4

 The diode testing scale of the DMM can be used to determine the condition of a diode.
With one polarity, the DMM should provide the “firing potential” of the diode, while the reverse
connection should result in an “OL” response to support the open-circuit approximation.
Using the connection in Fig. 2.3, constant-current source of about 2 mA internal to the
meter will forward-bias the junction and a voltage in the neighbourhood of 0.7 V (700 mV)
should be obtained for silicon. If the leads are reversed, an OL indication should be contained.
If a low reading (less than 1V) is obtained in both directions, the junction is shorted
internally. If an OL indication is obtained in both directions, the junction is open. Perform the
tests of Table 2.1 for the silicon diodes.

Resistance Scales

As indicated in the Principle of the Activity, the condition of a diode can also be checked
using the resistance scales of a VOM or digital meter. Using the appropriate scales of the VOM
or DMM, determine the resistance levels of the forward and reverse-bias regions of the Si diode.
Enter results in Table 2.2.
Although the firing potential is not revealed using the resistance scales, a “good” diode
will result in a lower resistance level in the forward bias state and a much higher resistance level
when reverse-biased.

Part 2. Forward-Bias Diode Characteristics

In this part of experiment, we will obtain sufficient data to plot the forward-bias
characteristics of the silicon diode on Fig. 2.5.

a. Construct the network of Fig. 2.4 with the supply (E) set to 0 V. Record the measured
value of the resistor.
b. Increase the supply voltage until VR (not E) reads 0.1 V. Then measure VD and insert in
Table 2.3. Calculate ID using the equation shown in Table 2.3.
c. On figure 2.5, plot ID versus VD for the silicon diode. Finish off the curves by extending
the lower region of the curve to the intersection of the axis at ID = 0 mA and VD = 0 V.
Label each curve and clearly indicate data points. Be neat!

Part 3. Reverse Bias

a. In Figure 2.6, a reverse-bias condition has been established. Since the reverse saturation
current will be relatively small, a large resistance of 1 MΩ is required if the voltage
across R is to be of measurable dimensions. Construct the circuit of Fig. 2.6 and record
the measured value of R on the diagram.

ACTIVITY 2: DIODE CHARACTERISTICS 5

 b. Measure the voltage VR. Calculate the reverse saturation current from Is = VR/(Rmeas||Rm).
The internal resistance (Rm) of the DMM is included because of the large magnitude of
the resistance R. Your instructor will provide the internal resistance of the DMM for your
calculations. If unavailable, use typical value of 10 MΩ.

Rm = 10 MΩ
(measured) VR = -19.44V
(Calculated) Is = -1.944x10-6 A

c. Determine the DC resistance levels for the silicon diode using the equation

(Calculated) RDC (Si) = 0.28 MΩ

Are the resistance levels sufficiently high enough to be considered open-circuit

equivalents if appearing in series with resistors in the low kilo-ohm range?

Yes, compared to the resistance of resistors in the low kilo ohm region, the values are effective as open circuits.

Part 4. DC Resistance

a. Using the SI curve plotted in Part 2 (c), determine the diode voltage at diode current
levels indicated in Table 2.4. Then determine the DC resistance at each current level.
Show all calculations.
RDC = Vd/Id
= 0.61 V/0.0002 A = 3050 Ω
= 0.654 V/0.001 A = 654 Ω
= 0.696 V/0.005 A = 130.8 Ω
= 0.714 V/0.01 A = 71.4 Ω
ID (Ma) VD RDC
0.2 0.61 V 3050 Ω
1 0.654 V 654 Ω
5 0.696 V 130.8 Ω
10 0.174 V 71.4 Ω

ACTIVITY 2: DIODE CHARACTERISTICS 6

 b. Are there any trends in DC resistance as the diode current increases and we move up the
vertical-rise section of the characteristics?
The vertical-rise section of the characteristics is inversely proportional to the DC resistance.

Part 5. AC Resistance

a. Using the equation rd = ∆V/∆I (Eq. 2.2), determine the AC resistance of the silicon diode
at ID = 9 mA using the curve plot of Part 2c. Show all work.

(calculated) rd =2 Ω
(0.714-0.712)/ (10-9) = 2 Ω

ACTIVITY 2: DIODE CHARACTERISTICS 7

 b. Determine the AC resistance at ID = 9 mA using the equation rd = 26 mV/ID (mA) for the
silicon diode. Show all work.
26 mV/9 mA = 2.8 Ω

How do the results of part (a) and part (b) compare?

The a and b values are slightly different from each other.

c. Repeat step 5(a) for ID = 2 mA for the silicon diode.

(calculated) rd = 5.5 Ω
(0.714-0.67) V/ (10-2) = 5.5 Ω

d. Repeat step 5(b) for ID = 2 mA for the silicon diode. Use Eq. 2.3.
(calculated) rd = 13 Ω
26 mV/2 mA = 13 Ω
How do the results of Part 5(c) and 5(d) compare?

The c and d have different values.

Part 6. Firing Potential

Graphically, determine the firing potential (threshold voltage) of each diode from its
characteristics as defined in the Principle of the Activity. Show the straight-line approximations
on Fig. 2.5.

VT (silicon) = 0.7 V

QUESTIONS:

1. Compare the characteristics of the silicon diode in the forward- and reverse-bias regions.
How are they similar and what are their most noticeable differences?
The forward bias has a bigger current than the reverse bias, whereas the reverse bias has a
lesser current. The backward bias has more resistant than the forward bias.

ACTIVITY 2: DIODE CHARACTERISTICS 8

 2. What is the effect of heat on the terminal resistance of semiconductor materials and
briefly review why the terminal resistance will decrease with the application of
heat?

The more thermal energy there is, the more energy the electrons absorb, resulting in more
conducting electrons and a lower resistance.

2.8 Activity Report

Section: 1-A Date Performed: 02/10/2022

Course Code: CPE0011L Date Submitted:
Course Title: Fundamentals of Electronics Circuit (Lab)
Instructor: Engr. Arnel Nuesca
Group No.: Activity No.: 2

Group Members: Signature:

1. Rupert Lance Y. Sobreviñas

2.
3.
4.
5.

2.8.1 Data and Results

Table 2.1

Test Si

Forward 0.7 V

Reverse OL

ACTIVITY 2: DIODE CHARACTERISTICS 9

 Table 2.2

Test Si

Forward 70 M Ω

Reverse OL

Table 2.3. VD versus ID for Silicon Diode

On the space below, plot ID versus VD for the

ACTIVITY 2: DIODE CHARACTERISTICS 10

 Figure 2.5

Table 2.4

ID (Ma) VD RDC

0.2 0.61 V 3050 Ω

1 0.654 V 654 Ω

5 0.696 V 130.8 Ω

10 0.714 V 71.4 Ω

ACTIVITY 2: DIODE CHARACTERISTICS 11

 2.8.2 Calculations
Part III:
b. Is = -19.44 v/ 10 M Ω = -1.944 x 10-6 A
c. Rdc = (20v – 19.44v)/ -1.944 x 10-6 A = 0.28 M Ω
Part IV:
a.
RDC = Vd/Id
= 0.61 V/0.0002 A = 3050 Ω
= 0.654 V/0.001 A = 654 Ω
= 0.696 V/0.005 A = 130.8 Ω
= 0.714 V/0.01 A = 71.4 Ω
b. 26mV/9mA = 2.8 Ω
c. (0.714-0.67) V/(10mA-2mA) = 5.5 Ω
d. 26 mV/2Ma = 13 Ω

2.8.3 Observations (if applicable)

Based on the results of Table 2.1, is the diode in good condition?

Yes, because the forward biasing allows current to flow through the diode, however reverse biasing
causes the diode to be in an open line condition, which is a sign of a good diode.

Based on the results of Table 2.2, is the diode in good condition?

Yes, because when the diode is forward biased, it has a low resistance level, but when it is reverse
biased, it has a high resistance level.

ACTIVITY 2: DIODE CHARACTERISTICS 12

 2.8.4 Conclusion/s
Therefore, the researcher concluded that the current in forward bias is greater than in reverse
bias. Forward bias has a higher resistance than reverse bias. The resistance will decrease as
more thermal energy is supplied to the terminal resistor. Forward bias diodes would give a
value in the multimeter as a response. In the multimeter, reverse bias diodes would react with
OL. The researcher may also state that resistance levels in DC and AC circuits can differ.

ACTIVITY 2: DIODE CHARACTERISTICS 13

 2.8.5 Rating (include Rubric)

Pre-initiation Initiating Implementing Refining Sustaining

Criteria
1 2 3 4 5

1. Activity Member does not Member follows good Member follows good Member follows good Member follows good and
Conduct follow good and safe and safe laboratory and safe laboratory and safe laboratory safe laboratory practice at
laboratory practice in practice some of the practice most of the practice at all times in all times in the conduct of
the conduct of activity. time in the conduct of time in the conduct of the conduct of activity. activity and encourages
activity. activity. others to do the same.
2.Equipment Member is unable to Member is able to Member is able to Member is able to Member is able to operate
Operation and operate the equipment operate equipment and operate equipment and operate the equipment the equipment and
Material and instruments. instrument with much instrument with and instruments with instruments with ease and
Handling supervision. supervision. ease and with without supervision.
minimum supervision.
3. Data The group has The group has The group has The group has The group has
Collection presented mostly presented relevant but presentedrelevant presentedrelevant presentedrelevant complete
irrelevant data. incompleteandinaccura partial but accurate and andalmost complete and accurate data.
te data. relevant data. but accurate data.

4. Data There are many There are some Analysis is partially Analysis is correct. Analysis is correct. The
Analysis and inaccuracies in inaccuracies in correct. The group The group recognized group recognized some
Evaluation analysis. The group did analysis. The group recognized some errors some errors and errors and inaccuracies in
not attempt to make didattempt to make and inaccuracies in the inaccuracies in the the processed, manipulated
some links to prior some links to prior processed, manipulated processed, manipulated and presented data. The
knowledge. knowledge. and presented data. and presented data. group is able to relate
The group is able to The group is able to presented data to other
make some links to make some links to knowledge.
prior knowledge. prior knowledge.

5. Results The group has no The group has vague The group has clear The group has clear The group has clear and
Interpretation interpretation of data interpretation of data and logical and logical logical interpretation of
and has invalid and conclusion is interpretation of data interpretation of data data and is able to draw
conclusion. fundamentally flawed. and/ attempts to and is able to draw suitable accurate
identify trends from some conclusions from conclusions from the data
the data. the data.

Total Score
Mean Score = (Total Score / 5)

Percentage Score = (Total Score / 25) x 100%

ACTIVITY 2: DIODE CHARACTERISTICS 14