LU6_Kirchhoff's Rules (1)
docx
keyboard_arrow_up
School
University Of Arizona *
*We aren’t endorsed by this school
Course
202
Subject
Electrical Engineering
Date
Jul 2, 2024
Type
docx
Pages
4
Uploaded by HighnessSalmonPerson564
Name ______________________ Class Section ________ Date _____________
PHY 242 – Laboratory
LABORATORY 6: KIRCHHOFF’S RULES
Objectives:
build circuits from schematic drawings.
measure the differences in potential and currents in series and
parallel combinations of resistors.
demonstrate Kirchhoff’s Rules for electrical circuits.
Materials Required:
Computer with Excel and access to simulation
Circuit Construction Kit
: https://phet.colorado.edu/en/simulation/circuit-construction-kit-dc
Software Requirements
: Windows
Macintosh
Chromebook
Linux
iPad
Mobile Phone
Chrome, Edge
Chrome, Safari
Chrome
Not recommended
Safari
Not recommended
Introduction:
Circuits consisting of just one battery and one load resistance are simple to analyze, but they are not often found
in practical applications. Usually, circuits have more than two components connected together. There are two
basic ways in which to connect more than two circuit components: series and parallel. The defining characteristic
of a series circuit is that there is only one path for electrons to flow. The
defining characteristic of a parallel circuit is that all components are
connected between the same set of electrically common points, therefore
they experience the same difference in potential. There are many paths for
electrons to flow, but only one voltage across all components. Series and
parallel resistor configurations have very different electrical properties. A multi-loop circuit may have more than one battery in different branches of
the circuit. A junction (node) in a circuit is a point where at least three circuit
paths meet. A branch is a path connecting two junctions (nodes). To analyze
such a circuit and to find the currents in all branches of the multi-loop circuit
one must use Kirchhoff's rules. a)
Kirchhoff's first rule (junction rule): At any junction point in a circuit
where the current can divide, the sum of the currents into the junction
(node) must equal the sum of the currents out of the junction (this is a
consequence of charge conservation). 1
b)
Kirchhoff's second rule (loop rule): When any closed-circuit loop is traversed, the algebraic sum of the
changes in the potential must equal zero (this is a consequence of conservation of energy).
Activity 1: Voltages in Series Circuits 1.
Start the Circuit Construction Kit
PhET simulation, Lab
tab, and explore it. Make sure that you check the Show Current (conventional), Labels
, and Values
boxes.
Hints for the use of various elements of circuit:
Right-click on the circuit element to change a property (e.g. resistance) or to delete it.
Right-click on junctions to disconnect pieces.
2.
Build a simple circuit with a battery, wires, and three resistors
of different resistances. Connect the three resistors into the
series circuit shown below carefully noting which wire is
connected to the negative and which is connected to the positive
terminal of the battery. Use the sliders (after clicking on the
element of circuit) to choose different values for the resistance
of resistors and the voltage of the battery.
3.
Use the voltmeter to measure the voltages across the individual resistors and then across the combinations of
resistors. Be careful to observe the polarity of the leads (red is +, black is -). Record your readings below.
R
1
=
¿
R
2
=
¿
R
3
=
¿
R
12
=
¿
R
23
=
¿
R
123
=
¿
V
1
=
¿
V
2
=
¿
V
3
=
¿
V
12
=
¿
V
23
=
¿
V
123
=
¿
4.
According to your data, what is the pattern for how voltage gets distributed in a series circuit with unequal
resistances? 5.
Is there any relationship between the size of the resistance and the size of the resulting voltage?
2
Activity 2: Voltages in Parallel Circuits 6.
Connect the three resistors into the parallel circuit shown below. 7.
Connect the wires to the battery, carefully noting which wire is connected to the
negative and which is connected to the positive.
8.
Use the voltmeter to measure the voltages across the individual resistors and then
across the combinations of resistors. Be careful to observe the polarity of the leads
(red is +, black is -). Record your readings below.
R
1
=
¿
R
2
=
¿
R
3
=
¿
R
123
=
¿
V
1
=
¿
V
2
=
¿
V
3
=
¿
V
123
=
¿
9.
According to your data, what is the pattern for how voltage gets distributed in a parallel circuit with unequal
resistances? 10.
Is there any relationship between the size of the resistance and the size of the resulting voltage?
Activity 3: Kirchhoff’s Rules
11.
Connect five resistors (of different resistances) in a circuit as the one shown in the figure.
12.
Record each resistance value in the space below. The total resistance R
total
of the circuit between points A and B, will be calculated using Ohm’s law R
total
=
V
total
/
I
total
once you measure the difference in potential and the current in each resistor.
¿
¿
¿
3
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
¿
=
¿
¿
=
¿
13.
On the circuit diagram in the figure above indicate which side of each of the resistors is at a higher potential
relative to the other end by placing a “+” at that end.
14. Use the ammeter to measure the current through each of the resistors. Make sure you record each of the
individual currents, as well as the current flow into or out of the main part of the circuit, I
total
.
15. Based on your data, calculate the net current flow into or out of each of the four “nodes” in the circuit (add
all the currents entering the nodes and subtract the currents leaving the node. Write down the net current
flow in or out of each of the four “nodes” in the circuit below.
16. For at least three (3) of the six closed
loops, calculate the net voltage drop based on your collected data.
Show your work in the space below. Note:
if the potential goes up, treat the voltage drop as positive (+),
while if the potential goes down, treat it as negative (-).
17. Use your results from the previous two steps to analyze the circuit in terms of Kirchhoff’s Rules. State the
evidence for your conclusions.
References: CC-BY license, PhET Interactive Simulations, University of Colorado Boulder, http://phet.colorado.edu 4
Related Questions
Ohm's Law states that the electric current flowing though a ________ is directly proportional to the ________.
Select one:
a. closed circuit --- total resistance
b. closed circuit --- switch resistance
c. open circuit --- supply voltage
d. closed circuit --- supply voltage
arrow_forward
QUESTION 7
Match Collumn A and Collumn B? Properties of Metal
v Britleness
A. the property of a metal which allows little bending or deformation without shattering
Conductivity
B. the property of metal to resist deformation and stress without breaking
the property of a metal which can be hammered, rolled. or pressed into various shape without
C.
v Hardness
cracking, breaking or leaving some other detrimental effect
v Strength
D. the property of a metal to resist cutting, penetration and abbrasion
v Elasticity
E. the weight of a unit volume of a material
F. the property of a metal to become liquid by the application of heat
v Malleability
the property of metal which enables a material to return to its original state when the force
G.
applied is removed
v Fusibility
v Density
H. the property of a metal to conduct electricity or heat
Click Save and Submit to save and submit. Click Save All Answers to save all answers.
Beno
arrow_forward
For a battery with a rated voltage = 12 V and a rated capacity = 350 A-h, determinea. The rated chemical energy stored in thebattery.b. The total charge that can be supplied at the ratedvoltage.
arrow_forward
Electrical Engineering
What is the smallest square box that will
accommodate four No. 12 conductors and
four No. 10 conductors if a. These
conductors are pulled through without a
splice? b. These conductors are all spliced in
the box?
arrow_forward
The exciting current of an electromagnet is rated at 12 amperes. When connected across a 122 - volt source the current is 14 amperes. Determine the ohms in a resistor which must be connected in series to limit the current to (a) rated value, and (b) 9 amperes.
arrow_forward
The waveform of a voltage source is shown in the given figure.
Let A = 2 and B = -3.8.
Determine the average current supplied to a 10-ohm resistor connected across the voltage source.
The average current supplied to a 10-ohm resistor connected across the voltage source is ______A.
arrow_forward
A cylindrical 4 AWG copper wire is coated with NEMA class A insulation. The normal operating
temperature of the wire is 50°C. What is the maximum current the wire can carry for 1 second
without exceeding the NEMA temperature rating?
arrow_forward
In the figure, the ideal batteries have emfs ℰ1 = 25.0 V and ℰ2 = 0.500ℰ1, and the resistances are each 2.14 Ω.
(a) What is the current in resistor 2? ______________A(b) What is the current in resistor 3? ______________A
(please show the units when working through the problem so that I can follow it easier)
arrow_forward
A cylindrical 00 AWG copper wire is coated with NEMA class B insulation. The normaloperating temperature of the wire is . What is the maximum current the wire can carry for 1second without exceeding the NEMA temperature rating?
arrow_forward
SEE MORE QUESTIONS
Recommended textbooks for you

EBK ELECTRICAL WIRING RESIDENTIAL
Electrical Engineering
ISBN:9781337516549
Author:Simmons
Publisher:CENGAGE LEARNING - CONSIGNMENT
Related Questions
- Ohm's Law states that the electric current flowing though a ________ is directly proportional to the ________. Select one: a. closed circuit --- total resistance b. closed circuit --- switch resistance c. open circuit --- supply voltage d. closed circuit --- supply voltagearrow_forwardQUESTION 7 Match Collumn A and Collumn B? Properties of Metal v Britleness A. the property of a metal which allows little bending or deformation without shattering Conductivity B. the property of metal to resist deformation and stress without breaking the property of a metal which can be hammered, rolled. or pressed into various shape without C. v Hardness cracking, breaking or leaving some other detrimental effect v Strength D. the property of a metal to resist cutting, penetration and abbrasion v Elasticity E. the weight of a unit volume of a material F. the property of a metal to become liquid by the application of heat v Malleability the property of metal which enables a material to return to its original state when the force G. applied is removed v Fusibility v Density H. the property of a metal to conduct electricity or heat Click Save and Submit to save and submit. Click Save All Answers to save all answers. Benoarrow_forwardFor a battery with a rated voltage = 12 V and a rated capacity = 350 A-h, determinea. The rated chemical energy stored in thebattery.b. The total charge that can be supplied at the ratedvoltage.arrow_forward
- Electrical Engineering What is the smallest square box that will accommodate four No. 12 conductors and four No. 10 conductors if a. These conductors are pulled through without a splice? b. These conductors are all spliced in the box?arrow_forwardThe exciting current of an electromagnet is rated at 12 amperes. When connected across a 122 - volt source the current is 14 amperes. Determine the ohms in a resistor which must be connected in series to limit the current to (a) rated value, and (b) 9 amperes.arrow_forwardThe waveform of a voltage source is shown in the given figure. Let A = 2 and B = -3.8. Determine the average current supplied to a 10-ohm resistor connected across the voltage source. The average current supplied to a 10-ohm resistor connected across the voltage source is ______A.arrow_forward
- A cylindrical 4 AWG copper wire is coated with NEMA class A insulation. The normal operating temperature of the wire is 50°C. What is the maximum current the wire can carry for 1 second without exceeding the NEMA temperature rating?arrow_forwardIn the figure, the ideal batteries have emfs ℰ1 = 25.0 V and ℰ2 = 0.500ℰ1, and the resistances are each 2.14 Ω. (a) What is the current in resistor 2? ______________A(b) What is the current in resistor 3? ______________A (please show the units when working through the problem so that I can follow it easier)arrow_forwardA cylindrical 00 AWG copper wire is coated with NEMA class B insulation. The normaloperating temperature of the wire is . What is the maximum current the wire can carry for 1second without exceeding the NEMA temperature rating?arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- EBK ELECTRICAL WIRING RESIDENTIALElectrical EngineeringISBN:9781337516549Author:SimmonsPublisher:CENGAGE LEARNING - CONSIGNMENT

EBK ELECTRICAL WIRING RESIDENTIAL
Electrical Engineering
ISBN:9781337516549
Author:Simmons
Publisher:CENGAGE LEARNING - CONSIGNMENT