PHY12L A5 E306 Group4 Mondejar

E306: SERIES AND PARALLEL CIRCUITS

MONDEJAR, Calvin Paulo A.

OBJECTIVE The purpose of this experiment is to find out the total current flowing through a series circuit and parallel circuit, to find out the voltage across each resistor and the current flowing through a series and parallel circuit, to analyze the relationship of voltage across each resistor to the total voltage, and to analyze the relationship of the current flowing through each resistor to the total current. The experiment has been performed for it is considered as a task to attain the objectives of the experiment likewise to attain data needed. In the experiment, the following data were sought: For table 1, which is the Series circuit, the resistance 1,2, and 3, the total resistance, the total voltage, the voltage across resistance 1, 2, and 3, current flowing through resistance 1, 2, and 3, the total current, and the percentage difference were asked. For table 2, which is the parallel circuit, the following data were also the same as the data mentioned in table 1. The experiment measured the missing values to determine the percentage difference of each table in the experiment like the each value of resistance, the net resistance, and the total voltage.

The significance of this experiment is the percentage difference determines the contrast of the values of experimental and actual. To attain this, the formulas provided by the manual for the series and parallel circuits experiment were used for computation likewise the other data were determined through experimental procedures. MATERIALS AND METHODS To attain the data needed by the series and parallel circuit experiment, the experiment was conducted by adhering to the procedures listed in the manual. Initially, materials were utilized for the series and parallel circuits experiment. The following materials used in the experiment with their use were: three pieces of resistance boxes which is used for adjusting the resistance, five pieces of 1.2 volts of batteries that serve as the supply of current to the resistance boxes, VOM and the ammeter, 12 pieces of connecting wires for connecting from one resistance box to another and likewise connected to the batteries, VOM and the ammeter, a piece of VOM or the Volt/Ohm meter for measuring the number of volts and ohms produced by the system, and a piece of ammeter used for determining the circuit’s electric current. 1|Page

for Series Circuit and the solved equivalent resistance and the voltage’s measurement across the batteries. Data were recorded from the experimental procedures followed for the table 1 of the experiment.

FIGURE 1. This figure shows the set-up of the materials for the series circuit part of the experiment 306.

Before the series and parallel circuits experiment started, the materials were set-up for the 1 st part of the experiment, which is the series circuit. The materials were checked like making sure that the resistance boxes, voltage batteries, connecting wires, VOM, and the ammeter function properly. When the materials were already set-up and ready for experimentation, the series circuit part of the experiment was performed. At the initial part of the experiment, the 5 batteries were connected to the VOM and the resistance boxes. After that, by utilizing the three resistors which are the three boxes, the circuit was built through connection of the wires by circuit diagram as provided by the manual and also a similar circuit diagram was provided by our professor. After building the circuit for the series circuit, the Volt/Ohm meter was connected at each resistor across the VOM one by one in order to determine the corresponding voltages listed in table 1. Since the VOM was connected at each resistor, the VOM was then connected to the circuit at corresponding points located in the table. By connecting the VOM to the circuit at following points, the equivalent resistance was determined. And after knowing the equivalent resistance, the total current’s value was computed after flowing through the circuit. Likewise, the total current’s value was computed while flowing through each resistor in the resistance box by utilizing Ohm’s Law and Rules

FIGURE 2. This figure shows the experimental value of the voltage across resistance 1 for the series circuit part.

Before the 2nd part of the series and parallel circuit experiment was performed, the materials were set-up for the parallel circuit part after the series part was finished. The materials were checked like the 1st part of the experiment except the arrangement of the parallel circuit is different from the arrangement of the series circuit. In order to perform the experiment, the group made sure that the resistance boxes, voltage batteries, connecting wires, VOM, and the ammeter function properly. When the materials were already set-up and ready for experimentation, the parallel circuit part was performed.

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FIGURE 3. This figure shows the set-up of the materials needed for performing the parallel circuit part of the experiment.

At the last part of the experiment which is the parallel circuit part, performing the experiment started when the batteries were connected in each resistor and in the VOM. After connecting the batteries, the circuit was built through utilizing the three resistors and through connecting the wires in the circuit diagram provided in the manual and likewise a similar circuit diagram for parallel circuit was provided by our professor. After building the circuit, the VOM was connected to the resistors one by one in order to define the corresponding voltages across each resistance. Moreover, the VOM was then connected to the circuit at corresponding points to measure the current. After connecting the VOM and gathering the measurement of the current, the equivalent resistance’s value was determined. Lastly, the total current’s value while flowing through the circuit, through each resistor, and the voltages across each resistor was them computed through the use of Ohm’s Law and Rules for Parallel Circuit and the equivalent resistance’s computed value and voltage’s measurement. After doing the procedures, the data were gathered and recorded for further computations for other remaining missing values.

FIGURE 4. This figure shows the experimental value of voltage across resistance 3 was determined by the ammeter.

OBSERVATIONS AND RESULTS The following below are the gathered data from the series and parallel circuits experiment, where the computed required values from table 1 and table 2 of the experiment were shown in the table below. TABLE 1. SERIES CIRCUIT

Resistance 1 = 89Ω Resistance 2 = 94Ω Resistance 3 = 115Ω

Total Resistance = 298Ω Total Voltage = 6.33V

TABLE 1

Experimental

Computed

Voltage Across Resistance 1

1.875V

1.780V

Voltage Across Resistance 2

1.974V

1.880V

Voltage Across Resistance 3

2.440V

2.300V

Current Flowing through Resistance 1 Current Flowing through Resistance 2 Current Flowing through Resistance 3 Total Current

0.020A

0.021A

0.020A

0.021A

0.020A

0.021A

0.020A

0.021A

Percentage Difference

6.021% 3|Page

SAMPLE COMPUTATION: TABLE 1. SERIES

each resistance was determined through using the VOM device that measured the amount of current in each resistor in Amperes. After knowing the current of each resistor, the total current was known given the formula for series

V 1 ( computed )=R1 I 1 V 1=( 89Ω)(0.020 A)

circuit,

V 1=1.78 V

TOTAL CURRENT ( A ) =

0.021−0.020 X 100 0.020+0.021 ( ) 2

%DIFFERENCE=6.021

In table 1, the values of resistance 1, 2, and 3 were provided in the experiment, the total resistance was computed by a formula of parallel in

which,”

RT =R1 + R2 + R3 ”.

V tot R1 + R2 + R3 ”.

TABLE 2. PARALLEL CIRCUIT

Resistance 1 = 96Ω Resistance 2 = 75Ω Resistance 3 = 51Ω

Total Resistance = 23.064Ω Total Voltage = 5.66V

TABLE 2

From table 1 of the experiment, series and parallel circuits, data were gathered through experimental procedures for the series circuit part. They are: Resistance 1, Resistance 2, Resistance 3, Total Resistance, Total Voltage, Experimental values of Voltage across Resistance 1, 2, and 3, Current Flowing through Resistance 1, 2, and 3, Total Current, and Percentage Difference.

circuit

TOTAL CURRENT ( A ) =

And by knowing the total current as an experimental value, percentage difference was computed to determine the amount of contrast between the experimental and computed value for the series circuit.

6.33 =0.021 A 89+ 94+115

PERCENTAGE DIFFERENCE=

“

The

voltage’s total of the resistors was determined through the use of ammeter. The ammeter measured the total voltage through connecting the wires to an arranged series circuit. After knowing the total voltage, the experimental value of voltage across each resistance was determined through measuring the amount of voltage in each resistor connecting from ammeter to each resistor. Moreover, the Current Flowing through

Experimental

Computed

Voltage Across Resistance 1

5.660V

4.800V

Voltage Across Resistance 2

5.660V

5.250V

Voltage Across Resistance 3

5.650V

5.100V

Current Flowing through Resistance 1 Current Flowing through Resistance 2 Current Flowing through Resistance 3 Total Current

0.050A

0.059A

0.070A

0.075A

0.100A

0.111A

0.230A

0.245A

Percentage Difference

6.481%

SAMPLE COMUTATION: TABLE 2.

V 1 ( computed )=R1 I 1 V 1=( 96 Ω)(0.050 A)

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V 1=4.80V

TOTAL CURRENT ( A ) =I 1 + I 2+ I 3 ”.

TOTAL CURRENT ( A ) =I 1 + I 2+ I 3 TOTALCURRENT ( A ) =0.059+0.075+0.111=0.245 A 0.245−0.230 PERCENTAGE DIFFERENCE= X 100 0.23+0.245 ( ) 2 %DIFFERENCE=6.481 The results from the table 2 of the experiment came from the data gathered in the experiment conducted. The following data gathered from the procedures of the experiment are: Resistance 1, Resistance 2, Resistance 3, Total Resistance, Total Voltage, Experimental values of Voltage across Resistance 1, 2, and 3, Current Flowing through Resistance 1, 2, and 3, Total Current, and Percentage Difference. The values of resistance 1, 2, and 3 were provided in the experiment, the total resistance was computed by a formula of parallel circuit in

which,”

RT =

1 1 1 1 ”. + + R1 R2 R3

The

voltage’s

total of the resistors was determined through the use of ammeter. The ammeter measured the total voltage through connecting the wires to a built parallel circuit. After knowing the total voltage, the experimental value of voltage across each resistance was determined through measuring the amount of voltage in each resistor connecting from ammeter to each resistor. Moreover, the Current Flowing through each resistance was determined through using the VOM device that measured the amount of current in each resistor in Amperes. After knowing the current of each resistor, the total current was known given the formula for parallel circuit, “

And

by

knowing the total current as an experimental value, percentage difference was computed to determine the amount of contrast between the experimental and computed value for the parallel circuit. DISCUSSION & CONCLUSION The series and parallel circuit experiment is an application of the Resistors in Series and Resistors in Parallel in Physics lecture. It is an application because series circuit is a type of circuit in which resistors are connected in series, resulting for the current to have one path to take, while a parallel circuit is a type of circuit in which resistors are connected in parallel, resulting for the current to break up in which particularly all of the current flow in each parallel section and they converge when the sections converge also. Series circuits result an equal value of current in each resistor and the circuit's net resistance can be found through adding all the resistance amounts of each resistor. Parallel circuits' voltage across each resistor has the same value likewise the net resistance of resistors in parallel can be solved by summing up each reciprocal of each resistor value and by getting the total's reciprocal. Ohm's law is also an application for the Electricity lecture in Physics in which the equation shows that the value of voltage is equivalent to a product between an electrical current and resistance. And by arranging the equation, the value of resistance is the ratio between the voltage and the electric current. This shows that the voltage has a directly relationship with the electric current and resistance, while the resistance has an inversely relationship with the electrical current. Based on the results of the experiment, I therefore conclude that understanding the circuit's concept particularly the series and parallel circuits is significant for studying this concept is the key on knowing the proportionality between the voltage and the resistance, voltage and electrical current, and resistance and 5|Page

electrical current. It is likewise significant to find out the comparison between the series and parallel circuit for they have different properties and arrangement for resistors. For the Series and Parallel circuit experiment, assuring that the multimeter's knob is in direct current and in voltage is important in order to evade errors in data. The connecting of wires improperly is an example of a possible error source. The proper connection of the wires is significant for the multimeter’s reading can alter if there is unstable connection. Moreover, when an ammeter is used, a device connected by a wire must replace the initial wires connected in the resistance boxes and the voltage batteries in order to make sure that electric current's reading is right. By the series and parallel circuit experiment, since the materials' experimental values were determined likewise the value of computed obtained by Ohm's law and by formulas provided by the two types of circuits, this manifests the validity of the circuit of parallel and series. ACKNOWLEDGMENT & REFERENCE First, I would like to thank almighty God for giving me strength to perform the series and parallel circuit experiment and other experiments with my group mates. I also would thank him for showering me blessings and for keeping me away from harm and danger. Secondly, I would like to thank my family for supporting my education and giving me love, joy, care, and other things. Thirdly, I also would like to thank General Physics Laboratory 3 instructor, Professor Ricardo de Leon, for teaching and discussing the series and parallel circuit experiment and other experiments of physics laboratory 3 this term. I also would like to thank him for his dedication in teaching

and his hard work to teach the experiment in order for his students to understand the experiment easily. I also would like to thank Professor De Leon for his generosity by giving us additional points for this experiment. I would like to thank my fellow group members for their effort, cooperation and teamwork in conducting this experiment and other experiments throughout the term. They are Ferdinand Almoite, Pria Mae Cadiz, Gian Brando Mercado, Gian Perez, and James Andrew Santiago. I would also like to thank them for performing the experiment chronologically and for their effort to finish the experiment as a group. Their efforts for the experiment were highly appreciated. Lastly, I would like to thank myself for performing the experiment and other experiments this term and for cooperating with my group mates likewise I thank myself for influencing my fellow members to strive for a good performance in order to obtain the desired result. This is the last lab report of the term and it’s really fun making this lab report and other lab reports. It really takes much dedication and effort to accomplish these lab reports and I am proud on what I have accomplished. These are the references below used to provide additional ideas regarding the experiment conducted: a. b. c.

http://physics.bu.edu/py106/notes/Circuits.ht ml http://hyperphysics.phyastr.gsu.edu/hbase/electric/ohmlaw.html Walker, J., Halliday, D., & Rensick, R. (2014). Principles of Physics Tenth edition, p. 462. Singapore: John Wiley and Sons Ltd., 2014

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