Report Principal 2

Report Assignment BENE 1133 Electric Principles

REPORT ASSIGNMENT1.0 TITLE

Series and Parallel Combination

2.0 OBJECTIVES

i. Construct circuit using Multisim Software.

ii. Compare result from Multisim Software and measurement.

iii. Understand the connection of multimeter when measuring voltage and current.

iv. The enhanced knowledge and understanding on series and parallel combination

v. To develop student skill in constructing electrical circuit and comparing the result

with theoretical and simulated value.

3.0 EQUIPMENT / MATERIALS

NO MATERIALS UNIT/S1 Resistor 4.7KΩ 12 Resistor 2.0KΩ 13 Resistor 1.0KΩ 14 Resistor 3.0KΩ 1

5 Resistor 5.6KΩ 1 6 Protoboard 1 7 Connecting wires 2

EQUIPMENT MODEL SERIAL NUMBERDigital Multimeter ( DMM )

AW MULTIMETER GDM 391A

07085011291

Power supply GPC – 3030D D 892316


4.0 THEORY

DMM (Digital Multimeter)

FIGURE 1: DIGITAL MULTIMETER

A DMM will have many functions built into it, and since there are many brands and

types of DMMs on the market, I will only go into the basics that they all have in

common. As with any tool or piece of equipment make sure you read and follow the

instructions and cautions that come with it. This will protect you and your equipment.

All DMMs will test for voltage, current and resistance. These are the three functions

you will use most when trying to diagnose a problem. When you purchase a DMM, one

of the most important things to look at is the meter's impedance, which is the meter's

operating resistance.

Most DMMs have very high impedance. Since the meter is part of the circuit being

tested, its resistance will affect the current flow through that circuit. If a DMM has a very

high impedance or resistance it will cause a slight increase in the circuit's current. This

becomes a concern when you test electronic systems because the increased current draw

can damage the components being tested or, at the very least, alter the readings or change

a sensor signal. You want to get a meter that has an impedance of at least 10 megaohms.

That is to say their current draw is so low it becomes invisible. Before you use your

DMM to perform a test, you need to know what you are testing and what kind of results


you are looking for. If you are looking for volts, you will need to select the proper range

for the test. If you are looking for a 12-volt result, select a meter range higher than 12

volts. For example, a 0 to 25 volt range would be best. A range of 0 to 500 volts will not

yield an accurate result. Almost all DMMs have an "auto-range" features that will

automatically select the proper range. Some DMMs will let you override this feature and

let you manually select the range you want. Some DMMs do not have this option and

must be set manually. Check the documentation that came with your DMM and make

sure you know and understand the different ranges it is capable of. Most DMMs that

have an auto-range will have the setting either before or after the reading. Ohms are

measured in multiples of ten and given the designation 'K' or 'M' with 'K' standing for

1,000 ohms and 'M' standing for 100,000,000 ohms. Amps would be displayed as mA,

milliamps or 1/1000 of an amp or A for full amps. Volts will also be displayed as mV or

volts. When you take a reading with a DMM that has auto-range, be sure you note at

what range the meter is on. You could mistake 10 mA as 10 amps.

Series and Parallel Circuit

Components of an electrical circuit or electronic circuit can be connected in many

different ways. The two simplest of these are called series and parallel and occur very

frequently. Components connected in series are connected along a single path, so the same

current flows through all of the components. Components connected in parallel are connected

so the same voltage is applied to each component.

A circuit composed solely of components connected in series is known as a series circuit;

likewise, one connected completely in parallel is known as a parallel circuit.

In a series circuit , the current through each of the components is the same, and the voltage

across the components is the sum of the voltages across each component.[ In a parallel circuit,

the voltage across each of the components is the same, and the total current is the sum of the

currents through each component. As an example, consider a very simple circuit consisting of

four light bulbs and one 6 V battery. If a wire joins the battery to one bulb, to the next bulb,

to the next bulb, to the next bulb, then back to the battery, in one continuous loop, the bulbs

are said to be in series. If each bulb is wired to the battery in a separate loop, the bulbs are

said to be in parallel. If the four light bulbs are connected in series, the same current flows

through all of them, and the voltage drop is 1.5 V across each bulb and that may not be

http://en.wikipedia.org/wiki/Battery_(electricity)

http://en.wikipedia.org/wiki/Voltage

http://en.wikipedia.org/wiki/Voltage

http://en.wikipedia.org/wiki/Electric_current

http://en.wikipedia.org/wiki/Topology_(electronics)

http://en.wikipedia.org/wiki/Topology_(electronics)

http://en.wikipedia.org/wiki/Electronic_circuit

http://en.wikipedia.org/wiki/Electrical_circuit


sufficient to make them glow. If the light bulbs are connected in parallel, the current flowing

through the light bulbs combine to form the current flowing in the battery, while the voltage

drop is 6.0 V across each bulb and they all glow.

In a series circuit, every device must function for the circuit to be complete. One bulb

burning out in a series circuit breaks the circuit. In parallel circuits, each light has its own

circuit, so all but one light could be burned out, and the last one will still function.

5.0 PROCEDURE

1. Circuit as shown in Figure 2 is constructed using Multisim Software.A 4.7KΩ, 2.0KΩ, 1.0KΩ, 3.0KΩ, 5.6KΩ resistor was used.

Find the value of current:


Find the value of voltage:

FIGURE 2: CONSTRUCTED CIRCUIT USING MULTISIM

2. The power supply was set to 12V as shown in Figure 3.

Figure 3

3. The DMM is connected in series with the resistor in order to get the value of the

current flow each resistor.

4. The Multisim is ran and the meter reading was recorded.

5. The step is then repeated by connect the DMM in parallel to get the value of the

voltage across each resistor.

6. Then, the circuit was constructed using the protoboard in the laboratory.

7. The result then was compared with the theoretical and simulated value.


6.0 RESULT

FROM PRACTICAL:

Measured resistance:Table 1.1

THEORETICAL VALUE MEASURED VALUE4.7KΩ 4.63K2.0KΩ 1.966K1.0KΩ 0.991K3.0KΩ 3.018K5.6KΩ 5.49K

Table 1.2

Resistor(Ω)Measured DMM (A) Measured DMM (V)

I1 I2 I3 V1 V2 V3

4.7K 456µ 459µ 458µ 2.161 2.162 2.162

3.0k 377.4µ 377.5µ 377.5µ 1.168 1.168 1.168

2.0k 1.10m 1.08m 1.11m 2.162 2.162 2.162

1.0k 1.18m 1.18m 1.18m 1.168 1.168 1.168

5.6k 1.548m 1.57m 1.57m 8.60 8.60 8.60


FROM THEORETICAL:

Calculation For Current:

RT=7.753Ω

IT = VsRT

= 127.753k

=1.548mA

For IR1

IR1 = R 2

R 2+R 1× IT

IR1= 2k

2 k+4.7 k×1.548 m

= 462.1µA

For IR2,

IR2= R 1

R 1+R 2x IT

IR2=4.7 k

2k+4.7 k×1.548m

= 1.086mA

For IR3,

IR3 = R 4

R 4+R 3 x IT

IR3=3 k

3k+1k x 1.548m

=1.161mA

For IR4,

IR4 = R 3

R 3+R 4x IT

IR4 = 1k

1k+3k x 1.548m

= 387µA

For IRa = IR1+ IR2

= 462.1µ + 1.086m = 1.548mA


For IRb = IR3 + IR4

= 1.161 m + 387 µ = 1.548 mA

For IRa + IRb = IR5

IR5 = 1.548 mA

Calculation for voltage

For VR1, \VR1 = IR1 x R1

= (462.1µ)( 4.7k) = 2.172v

For VR2,VR2= IR2 x R2

= (1.036m)(2k) = 2.172v

For VR3, VR3 = IR3 x R3

= (1.161m) (1k) = 1.161v

For VR4

VR4 =IR4 x R3 = (387µ)(3k) = 1.161v

For VR5,VR5 = IR5 x R5

= (1.548m) (5.6k) = 8.669V


Current Measurement

For R1 4.7KΩ

For R2 2.0KΩ

For R3 1KΩ


For R4 3KΩ

For R5 5.6KΩ

Voltage Measurement:

For R1 4.7KΩ


For R2 2.0KΩ

For R3 1KΩ

For R4 3KΩ

For R5 5.6KΩ


FROM MULTISIM:

Measure the current for each resistors:

1.1 Circuit for simulation

Measure the value of voltage:


1.2 Circuit for simulation

COMPARISON RESULTS FOR THEORETICAL, PRATICAL AND SIMULATION

Table 1.3 : FOR CURRENT

RESISTORS(Ω) THEORETICAL (A)

PRACTICAL(A) SIMULATION(A)

R1= 4.7K 462.1µA 456µ 463.629 µ

R2=2.0k 1.086m 1.10m 1.085m

R3=1.0k 1.161m 1.18m 1.160m

R4=3.0k 387 .0µ 377.4µ 389.022µ

R5=5.6k 1.548 m 1.548m 1.547m

Table 1.4 :FOR VOLTAGE

Resistors (Ω) THEORETICAL

(V)

PRACTICAL (V) SIMULATION (V)


R1= 4.7k 2.172 2.161 2.784

R2 = 2.0k 2.172 2.162 2.784

R3 = 1.0k 1.161 1.168 1.088

R4 = 3.0k 1.161 1.168 1.088

R5 = 5.6k 8.669 8.600 8.127

7.0 DISCUSSION

The result obtained by using DMM is not very accurate compare to multisim since the

readings have a slightly difference from the reading predicted by calculation.

The result obtained can have more decimal places by using multisim asmultisim can only

read up to 3 decimal places without error and have higher sensitivity. There are several

advantages of using multisim compared to electrical instrument like DMM.

i. The result obtain are more accurate, since it has higher sensitivity.

ii. Decrease the chancesof having gross error, systematic error, and random error.

iii. The experiment can carried out easily.

iv. Circuit component or instruments will not be damaged.

` Before you use your DMM to perform a test, you need to know what you are testing

and what kind of results you are looking for. If you are looking for volts, you will need to

select the proper range for the test.

If you are looking for a 12-volt result, select a meter range higher than 12 volts. For

example, a 0 to 25 volt range would be best. A range of 0 to 500 volts will not yield an

accurate result.


Almost all DMMs have an "auto-range" features that will automatically select the

proper range. Some DMMs will let you override this feature and let you manually select the

range you want.

Some DMMs do not have this option and must be set manually. Check the documentation

that came with your DMM and make sure you know and understand the different ranges it is

capable of.

Most DMMs that have an auto-range will have the setting either before or after the

reading. Ohms are measured in multiples of ten and given the designation 'K' or 'M' with 'K'

standing for 1,000 ohms and 'M' standing for 100,000,000 ohms.

There is only one current I, in a series circuit.I=VT/RT, where VT is the voltage applied

across the total series resistance RT.This I is the same all the series components.

The total resistance RT of a series string is the sum of the individual

resistances.RT=R1+R2+R3....

The applied voltage VT equals the sum of the series IR voltages drops.V=IR.

The negative side of an IR voltage drop is where electrons flow in,attracted to the positive

side at the opposite end.

The sum of the individual values of power used in the individual resistances equals

the total power supplied by the source.

Series-aiding voltages are added:series –opposing voltages are subtracted. An open

circuit result in no current in all part of the series circuit.In an open circuit, the voltage across

the two open terminals is equal to the apply voltage.

There is only one voltage VA across all components in parallel. The current in each

branch Ib equals the voltage VA across the branch devided by the branch resistance Rb Or Ib =

VA/Rb. The total line current equals the sum of all branch currents. Or IT = I1=I2=I3.......

For the general case of any number of branches, calculate REQ as VA/IT or use the

reciprocal resistance formula:I/REQ=I/R1+I/R2+I/R3.....The sum of the individuals values of

power dissipated in parallel resistances equals the total power by the source. Based on our

comparison, in table 1.3 for current the value from theoretical and simulation most same but

for practical the value is most different this is because some error such gross error. Its means

that human mistake in reading and using instrument or errors in recording observations. So

that, we repeat the experiment until three times to get the more accurate value. For voltage in

table 1.4 we also compared the value of voltage and the value of simulation is more different,

this is because of some error in multisim. Means that the connection in multisim make the


value of voltage is more different from theoretical and practical. We also repeat this

experiment for three times to get the more accurate value for voltage.

8.0 CONCLUSION

From this assignment, we have been introduced to the topic of series and parallel

combination through the subject of Electronic Principle. After completing the assignment, we

are more familiar with the usage of the digital multimeter. We are taught the way to design a

circuit of series and parallel combination. In the other hand, we are able to apply the formula

that we have learnt to calculate the voltage through a circuit of series and parallel

combination.At the end, with the help of the lecturer and the guidance given, we are manage

to accomplish the assignment successfully and get to understand more about Multisim

Software and how to construct series and parallel circuit.

9.0 REFERENCES

Book Sources:

i. Kalsi H.S., “Electronic Instrumentation”, Second Edition, Tata McGraw Hill,

2004.

ii. Bernard Grob, “Electronic Instrumentation”, Eighth Edition, Tata McGraw Hill,

2001.

Internet sources:

i. http://en.wikipedia.org/wiki/Series_and_parallel_circuits

http://en.wikipedia.org/wiki/Series_and_parallel_circuits

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