lab manual electric circuit

7/29/2019 Lab Manual Electric Circuit

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By:

Rizwan Khan

Ahmed Mohiuddin

University of Engineering & Technology (Rachna Campus)

Gujranwala, Pakistan


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EXPERIMENT#1

Verification of CURRENT DIVISION RULE (CDR)

APPARATUS

ResistorVoltmeter

Voltage source

Bread board

CIRCUIT DIAGRAM

THEORY

Current division rule (CDR) states that

current divide it self inversely Proportional to the resistanceIt means that greater the resister less will be the current and vice versa.This experiment is use to find current through resistor which are in parallel to

Each other.


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PROCEDURE

Form a circuit as shownFind currents through resistors R1, R2, R3 respectively now find source current using

Formula

Also calculate currents using formulaFinally calculate error between calculated value and experiment value

CALCULATIONS


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EXPERIMENT#2

Read color coding of carbon resistor

APPARATUS:

Four different resistors

CIRCUIT DIAGRAM:

PROCEDURE

To read the resistance of particular resistor write first no of corresponding

First color band similarly write no. of second color band. In the case of third color band

Write the no. to the power of 10. In some resistors there is fourth band. This band is fortolerance. Its color may be Golden, silver having tolerance 5%, 10% respectively.

If there is no band then its tolerance will be 20%.


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EXPRIMENT#3

TO CALCULATE FREQUENCE OF WAVE USING OSCILLOSCOPE

PROCEDURE

Connect nabs wave generator with oscilloscope and form wave

On generator on time axis each big division consist of 5 small divisions.

Calculate small division and multiply it with number on voltage control nab

In this way we will

TIME PERIOD

As we know reciprocal of time period of wave is frequency so use formula

To calculate frequency

TO CALCULATE VOLTAGE OF WAVE

Calculate no of small division and

Multiply it with no. voltage control nab.


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Experiment#4

Introduction to Oscilloscope

Oscilloscopes:

When you connect an oscilloscope probe to a circuit, the voltage signal travels through

the probe to the vertical system of the oscilloscope. Figure 6 is a simple block diagram

that shows how an analog oscilloscope displays a measured signal.

Analog Oscilloscope Block Diagram

Depending on how you set the vertical scale (volts/div control), an attenuatorreduces the

signal voltage or an amplifierincreases the signal voltage.

Next, the signal travels directly to the vertical deflection plates of the cathode ray tube

(CRT). Voltage applied to these deflection plates causes a glowing dot to move. (An


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electron beam hitting phosphor inside the CRT creates the glowing dot.) A positive

voltage causes the dot to move up while a negative voltage causes the dot to move down.

What Can You Do With It?

Oscilloscopes are used by everyone from television repair technicians to physicists. Theyare indispensable for anyone designing or repairing electronic equipment.

The usefulness of an oscilloscope is not limited to the world of electronics. With the

propertransducer, an oscilloscope can measure all kinds of phenomena. A transducer is adevice that creates an electrical signal in response to physical stimuli, such as sound,

mechanical stress, pressure, light, or heat. For example, a microphone is a transducer.

An automotive engineer uses an oscilloscope to measure engine vibrations. A medical

researcher uses an oscilloscope to measure brain waves. The possibilities are endless.

How Does an Oscilloscope Work?

To better understand the oscilloscope controls, you need to know a little more about how

oscilloscopes display a signal. Analog oscilloscopes work somewhat differently thandigital oscilloscopes. However, several of the internal systems are similar. Analog

oscilloscopes are somewhat simpler in concept and are described first, followed by a

description of digital oscilloscopes.


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EXPERIMENT#5

Verification of KCL

APPARATUS:

Resistor

Voltmeter

Voltage sourceBread board

CIRCUIT DIAGRAM:

THEORY:

KCL states that

Algebraic sum of all currents through node is zero .If it is assume that current loss

through wire is zero then sum of current at any node is zero

PROCEDURE:

Calculate current through each resister using ammeter and verify these equations to proveKCL


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CALCULATIONS:


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EXPERIMENT#5

Verification of KVL

APPARATUS:

Resistor

Voltmeter


CIRCUIT.DIAGRAM:

THEORY:

Kirchhoffs voltage law states that

Algebraic sum of all voltages along a close path must be equal to zero. Hence anyvoltage can be found using KVL in mathematical form

PROCEDURE:

Form a circuit as shown in fig

Take voltmeter and find voltage across each resister or take ammeter and find currentusing current find voltmeter. After this verify the equations


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CALCULATIONS:


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EXPERIMENT#7

MAXIMUM POWER TRANSFOR THEOREM

APPARATUS

Resistor

Voltmeter


CIRCUIT.DIAGRAM

Where R=2.2K

RL=1K, 2K, 2.2K, 2.7K

THEORY

Power will max when load resistance is equal to internal resistance of voltage source.

PROCEDURE

As we know power across RL will max when RL=RSo find current and use formula to calculate power.

CALCULATIONS:


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EXPERIMENT#8

VARIFICATION OF OHM LAW

APPARATUS:

Ammeter

Voltage source

Resistor

CIRCUIT DIAGRAM:

R=2K

THEORY:

According to ohm law

Voltage across resister is directly proportional to current. Hence when voltage

increases current increases and vice versa.So It can be use to determined voltage or current.

PROCEDURE:

Calculate current using ammeter then use this formula to calculate

Voltage across the resister


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EXPERIMENT#9

Power equation verification

APPARATUS:

AmmeterVoltage source

Resistor

CIRCUIT DIAGRAM:

THEORY:

As we know that in an ideal circuit power loss across connecting wires is

Zero. So all the power delivered by voltage source must be equal to the power across

Circuit because we assume that power loss across resistor is zero.

PROCEDURE:

From circuit as shown using Ammeter find out value of

Current. Using this value find Power using different formulas

P= V*I

P= (I*I)*R

P= (V*V)/R


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CALCULATIONS:


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EXPERIMENT#10

To observe the response of R-C series circuit

PURPOSE:

The main purpose is to perform this experiment is to study charging and discharging time

of a capacitor and study its waveform.

APPARATUS:

Resistor 0.1K

Capacitor 0.01

OscilloscopeFunction generator

Bread boardConnecting wires

PROCEDURE:

First o all made a circuit using resistor , capacitor , function generator in series onbread board as shown.

Now take an oscilloscope connect probes of ch1 across the unction generator and

Connect probes of ch2 across capacitorWhen signal is given to the circuit by function generator then waveform of out put

Is shown on oscilloscope then observe waveform of out put signal.

CIRCUIT DIAGRAM:


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THEORY:

When input signal is given to the circuit the charging current begins to flow and

Start charging the capacitor on though the resistor an is increase slowly. Finally

Reach at maximum value

Q=CV

The voltage across the capacitor at any time is given by

V= q/c

The speed of charging and discharging depends upon the product of resistor R

And capacitance C of capacitor used in circuit .

Its unit sec an called as time constant.

GRAPH:

TIME CONSTANT:

It is defined as

The time during which capacitor is charged or discharged up to 63% of its original

value

The graph shows that charging reach to its max value sooner when time constant isSmall and it is small when time constant is small.


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EXPERIMENT#11

TO VARIFY THE PRINCIPLE OF SUPER POSITION

APPARATUS:

Resistor

VoltmeterVoltage source

Bread board

CIRCUIT.DIAGRAM:

THEORY

Super position theorem states that

In a linear circuit containing multiple sources current or voltage at any point in the

network may be calculated as sum of individual contributions of each source actingaloneHence this theorem is use to determined voltage across resistor when there areMany voltage sources.

PROCEDURE:

Form the circuit as shownDisconnect Vb1 and calculate voltages across each resistor. Now disconnect Vb2 and

Calculate voltages across each resistor now according to super position in order toGet actual voltage sum these voltages.


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CALCULATIONS:


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EXPERIMENT#12

Verification of Thevenins Theorem

APPARATUS:

ResistorVoltmeter

Voltage source

Bread board

CIRCUIT DIAGRAM:

THEORY:

As we know Thevenins theorem is use to simplify complex circuit

Using this theorem we get only one resistor in series with Load and voltageSource

PROCEDURE:

Thevenins theorem states that

Entire circuit exclusive of load can be converted in to an equivalent circuit contain

voltage source in series with resistor

Calculate v using voltmeter and then calculate it theoretically


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CALCULATIONS:


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EXPERIMENT#13

Verification of Voltage Division Rule (V.D.R)

APPARATUS:

Resistor

Voltmeter


CIRCUIT DIAGRAM:

THEORY:

According to voltage division rule

Voltage divide itself proportional to the resistance across the resister, In other

words greater the resistance greater will be the voltage across itThis rule is use to know voltage across any resistor if they are connected in series with

Voltage source.

PROCEDURE:

Connect 3 resister in series with voltage source .Using voltmeter calculate voltage across

each resister or use formula to calculate voltages acrossResister

Where I=1, 2, 3,


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CALCULATIONS:

lab manual electric circuit

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