LABORATORY EXERCISE NO. 5
Voltage-current relationship in
resistive elements with varying
frequency
OBJECTIVES:
At the end of this laboratory exercise, the students are expected to:
1. Comprehend the behavior of a pure R element;
2. Relate the behavior of the voltage to current and vice versa in a
pure R element with varying frequency;
3. Connect the electrical wiring diagram of an alternating current
circuit system.
MATERIALS/EQUIPMENT REQUIRED:
Quantity
Materials/Equipment
1 pc.
Voltmeter
1 pc.
Ammeter
1 pc.
Resistors (1 kilo-ohm)
1 pc.
Health kit
20 pcs.
Connecting Wires
1 set
Power supply
For circuit simulation, use MULTISIM (www.multisim.com)
Introduction:
Electricity
is
produced
by
generators
at
a
power
stations
and
then
distributed by a vast network of transmission lines to industry and for domestic
use. It is easier and cheaper to generate alternating current than direct current
and ac is more conveniently distributed than dc since its voltage can readily be
altered using transformers.
Figure 1. Pure Resistive Load
Procedures:
1. Connect a 230V 1kHz 0O AC source to a resistive load measuring 1
kilo-ohm. Record the voltage wave and current wave formed by the
circuit. Use voltmeter and ammeter for the analysis and annotation.
2. Connect a 230V 10kHz 0O AC source to a resistive load measuring 1
kilo-ohm. Record the voltage wave and current wave formed by the
circuit. Use voltmeter and ammeter for the analysis and annotation.
3. Connect a 230V 100kHz 0O AC source to a resistive load measuring 1
kilo-ohm. Record the voltage wave and current wave formed by the
circuit. Use voltmeter and ammeter for the analysis and annotation.
Analysis
1. In procedure 1, show the circuit connection and express the
instantaneous equations of the voltage and the current. Insert the
two waves in one picture and discuss by comparing the behaviors of
the two waves.
2. Repeat the same for procedures 2 and 3.
3. Compare the voltage wave of 1 to 2 and 3. Likewise, compare the
current wave of 1 to 2 and 3.
Conclusion:
Discussion should focus on the behavior of the waves as the frequency
changes.