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    Jawaharlal Nehru Engineering Collage

    Laboratory Manual

    Electronics Devices and Circuits


    Second Year Students

    Manual made by


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    Jawaharlal Nehru Engineering College

    Technical Document

    This technical document is a series of Laboratory manuals of Electronics and

    Telecommunication Department and is a certified document of Jawaharlal Nehru

    engineering College. The care has been taken to make the document error-free. But

    still if any error is found, kindly bring it to the notice of subject teacher and HOD.

    Recommended by,


    Approved by,


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    It is my great pleasure to present this laboratory manual for second year

    engineering students for the subject of Electronic Devices &circuits to understand

    and visualize the basic concepts of various circuits using electronic components.

    Electronic Devices &circuits cover basic concepts of electronics. This being a core

    subject, it becomes very essential to have clear theoretical and designing aspects.

    This lab manual provides a platform to the students for understanding the basic

    concepts of electronic devices and circuits. This practical background will help

    students to gain confidence in qualitative and quantitative approach to electronic


    Good Luck for your Enjoyable Laboratory Sessions.


    ECT Dept

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    This manual is intended for the Second Year students of ECT branches in the

    subject of Electronic Devices & Circuits. This manual typically contains practical/

    Lab Sessions related to Electronic Devices & Circuits covering various aspects

    related to the subject for enhanced understanding.

    Students are advised to thoroughly go through this manual rather than only topics

    mentioned in the syllabus as practical aspects are the key to understanding and

    conceptual visualization of theoretical aspects covered in the books.

    Good Luck for your enjoyable Laboratory Sessions.

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    1. Dos & Donts in Laboratory.

    2. Lab Exercises

    1. To plot VI characteristic of PN junction diode.

    2. For Full wave bridge rectifier with capacitor filter find the ripple factor.

    3. To plot the output V-I characteristics of Bipolar Junction Transistor.

    4. To study the two stage RC Coupled Amplifier using Transistor to plot a frequency response.

    5. To plot the drain characteristics of N-channel JFET.

    6. To plot the drain characteristics of N-channel MOSFET.

    7. Study of RC integrator for sine, square wave input. 8. To study the circuit of Colpitts or LC Oscillator & Determine the output

    frequency of Oscillator.

    3. Quiz

    4. Conduction of viva voce examination

    5. Evaluation & marking scheme

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    Dos and Donts in Laboratory :-

    1. Do not handle any equipment before reading the instructions /Instruction manuals.

    2. Read carefully the power ratings of the equipment before it is switched ON,

    whether ratings 230 V/50 Hz or 115V/60 Hz. For Indian equipment, the power

    ratings are normally 230V/50Hz. If you have equipment with 115/60 Hz

    ratings, do not insert power plug, as our normal supply is 230V/50Hz., which

    will damage the equipment.

    3. Observe type of sockets of equipment power to avoid mechanical damage.

    4. Do not forcefully place connectors to avoid the damage.

    5. Strictly observe the instructions given by the Teacher/ Lab Instructor.

    Instruction for Laboratory Teachers:-

    1. Submission related to whatever lab work has been completed should be done

    during the next lab session.

    2. Students should be instructed to switch on the power supply after getting the

    checked by the lab assistant / teacher. After the experiment is over, the students

    must hand over the circuit board, wires, CRO probe to the lab assistant/teacher.

    3. The promptness of submission should be encouraged by way of marking and

    evaluation patterns that will benefit the sincere students.

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    Exercise No.1 :(2 Hours)

    Aim:- To plot VI characteristic of PN junction diode.

    Apparatus:- D.C.regulated power supply (0-30V) , Diode(1N4007), Resistance

    (1K ), voltmeter(0-10V), ammeter (0-25mA), Connecting wires.

    Circuit Diagram:-


    1. Connect the circuit as shown in fig.

    2. By varying applied voltage measure corresponding reading for voltage &


    3. Plot the graph of voltage & forward current.

    V Vf

    0-10V D Si




    R 0-25mA


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    Vdc ( V)

    O/P Voltage

    Vf ( V)


    If ( mA)









    Forward V-I Characteristics of PN Junction Diode :-

    Conclusion: - Current increases exponentially with respect to voltage after cut in

    voltage as seen from the graph.

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    Exercise No.2 :( 2 Hours)

    Aim: - For Full wave bridge rectifier with capacitor filter find the ripple factor.

    Apparatus: - Step Down transformer, 04 Diodes- (1N4007), Resistance (1K),

    capacitor (1000 F), voltmeter, oscilloscope, connecting wires.

    Circuit Diagram :-


    1. Connect the circuit as shown in fig.

    2. By applying AC input voltage measure corresponding reading for output voltage

    (Peak, RMS).

    3. Observe the output DC voltage.

    4. Calculate ripple factor.


    Ripple Factor: = VRMS / VDC





    + C


    1K Vout

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    Applied input

    peak voltage


    Peak Output



    RMS Output



    DC Output



    Input and Output Waveforms for Full Wave bridge Rectifier with Capacitor


    Result:- Ripple Factor (Calculated)=

    Ripple Factor (Measured) =

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    Exercise No.3 :(2 Hours):-

    Aim: - To plot the output V-I characteristics of Bipolar Junction Transistor.

    Apparatus: - Transistor (BC 107), Regulated Power Supply (0-15V), Regulated

    Power Supply (0-30V), Voltmeter (0-20V), Ammeter (0-200A),

    Ammeter (0-100mA), Resistors, Bread board, connecting wires.

    Circuit Diagram :-


    Output characteristics:

    1. Connect the circuit as per the circuit diagram

    2. For plotting the output characteristics the input current IB is kept constant at

    20A and for different values of VCE note down the values of IC.

    3. Repeat Step 2 for IB at 40A and 60A.

    4. Tabulate the all the readings.

    5. Plot the graph between VCE and IC for constant IB.


    1. The supply voltage should not exceed the rating of the transistor

    2. Meters should be connected properly according to their polarities

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    Sr.No IB = 10 A IB = 20 A IB = 30 A

    VCE(V) IC(mA) VCE(V) IC(mA) VCE(V) IC(mA)

    1 0.1 0.1 0.1

    2 0.2 0.2 0.2

    3 0.3 0.3 0.3

    4 0.4 0.4 0.4

    5 0.5 0.5 0.5

    6 0.8 0.8 0.8

    7 1.0 1.0 1.0

    8 2.0 2.0 2.0

    9 3.0 3.0 3.0

    10 4.0 4.0 4.0

    11 5.0 5.0 5.0

    Output Characteristics of BJT:

    Conclusion: The output current Ic depends on input current Ib and hence, output

    characteristics of a transistor in CE configuration show that a BJT is current

    controlled device.

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    Exercise No.4 :(2 Hours):-

    Aim: - To study the two stage RC Coupled Amplifier using Transistor to plot a

    frequency response.

    Apparatus: - Function generator, CRO, RC coupled Amplifier kit

    Circuit Diagram: -


    1. Connect the signal generator at the input terminals of the circuit.

    2. Connect the CRO at the output.

    3. Switch on the power supply.

    4. Keep the input signal amplitude Vin constant of 100 mV, so that transistors

    should not enter in saturation.

    5. Now vary the input frequency Fi from 100 Hz to 100 kHz in steps. Observe

    & note the corresponding output voltage Vo. Find out the voltage gain Av.

    6. Plot the graph between input frequency & voltage gain.

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    Observation Table:- Vin =100 mV

    Sr. No I/P Frequency


    O/P Voltage

    (Volts) Gain (Av) =


    1 100

    2 200

    3 300

    4 500

    5 800

    6 1K

    7 2K

    8 3K

    9 5K

    10 10K

    11 20K

    12 30K

    13 50K

    14 100K


    Bandwidth of R-C Coupled amplifier is:

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    Exercise No.5 :(2 Hours):-

    Aim: - To plot the drain characteristics of N-channel JFET.

    Apparatus: - JFET (BFW10), Regulated Power Supply (0-12V), Reg


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