SRI SAIBABA NATIONAL COLLEGE::ANANATPUR

(Autonomous)

Department of Electronics

B.Sc., Electronics I Year Practicals

Prepared By

Dr.C.Saritha Dr.V.Sukanya

SSBN DEGREE (Autonomous) COLLEGEDepartment of Electronics

B.Sc., I year - List of Experiments

1. Conversion of Basic meter into ohm meter

2. Verification of Kirchoff”s Laws

3. Verification of Thevenin’s and Norton’s theorems

4. Measurement of voltage (ac and dc) and frequency using CRO

5. Verification of Maximum power transfer theorem

6. Frequency response of CR circuit

7. Conversion of basic meter into voltmeter

8. VI characteristics of PN junction diode

9. VI characteristics of Zener diode

10. Zener diode voltage and current regulation characteristics

1. Conversion of Basic meter into ohm meter

Aim:

To convert the given micro ammeter into ohm meter and also to determine the unknown

resistance values by using the ohm meter.

Apparatus:

Battery eliminator (1.5V), micro ammeter (0-200μA), Resistance box (2), multimeter, plug

key, bread board, connecting wires etc.

Circuit diagram:

Model Graph:

Tabular Column:

S.No. Resistance in ohms Deflections in divisions

1 500

2 1000

3 1500

4 2000

5 2500

6 3000

7 3500

8 4000

9 4500

10 5000

11 5500

12 6000

13 6500

14 7000

15 7500

16 8000

17 8500

18 9000

19 9500

20 10000

21 R1( )

22 R2( )

23 R3( )

24 R4( )

25 R5( )

Result :

The given micro ammeter is converted into ohmmeter and the values of unknown

resistances are determined by using the graph.

S.No. Resistors of different values Resistance in Ω

Fromcolour code

From multimeter

From Graph

1 R1( )

2 R2( )

3 R3( )

4 R4( )

5 R5( )

2. Verification of Kirchoff”s Laws

Aim :

To verify the kirchoff’s voltage and current laws by arranging simple electric circuits.

Apparatus :

Resistors of different values, Battery eliminator, multimeter, bread board and connecting

wires etc.

General circuit diagrams:

Kirchoff’s Current Law:

Kirchoff’s Voltage Law:

Circuit diagram:

Observation Table for Kirchoff’s Voltage Law :

S.No. Input

voltage Vi

in volts

Voltage

VAB

in volts

Voltage

VBC

in volts

Voltage

VCD

in volts

Voltage

VDE

in volts

Total ouput voltage

Vo = VAB + VBC + VCD + VDE

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

Observation Table for Kirchoff’s Current Law :

S.No.

in mA in mA in mA in mA in mA in mA

in mA in mA

1

2

3

4

5

6

7

8

9

10

Result :

Kirchoff’s voltage law and Kirchoff’s current law are verified by arranging simple electric

circuit.

S.No. in mA in mA in mA in mA

1

2

3

4

5

6

7

8

9

10

3. Verification of Thevenin’s and Norton’s theorems

Aim:

To state and verify Norton’s theorem and Thevenin’s theorem by using the suitable electric

circuits.

Apparatus :

Resistors 100Ω (2), Resistance Box (1), multimeter, Battery eliminator, voltmeter (0-10V),

milliammeter (0-10mA), bread board and connecting wires etc.

General Circuit :

To find Thevenin’s Resistance :

Observation Table to find Thevenin’s Resistance (Rth):

S.No. Resistance in Ω Thevenin’s Resistance Rth in Ω

R1 R2 R3 Experimental Value Theoretical Value

in Ω

1 100 100 100

2 100 200 100

3 100 300 100

4 100 400 100

5 100 500 100

6 100 600 100

7 100 700 100

8 100 800 100

9 100 900 100

10 100 1000 100

To find Thevenin’s Voltage:

Observation Table to find Thevenin’s Voltage (Vth) :

S.No. Resistance in Ω Thevenin’s Voltage Vth in Volts

R1 R2 R3 Experimental

Value

Theoretical Value

in volts

1 100 100 100

2 100 200 100

3 100 300 100

4 100 400 100

5 100 500 100

6 100 600 100

7 100 700 100

8 100 800 100

9 100 900 100

10 100 1000 100

To find Norton’s Current ( IN ):

Observation Table to find Norton’s Current ( IN ) :

S.No. Resistance in Ω Norton’s Current IN in mA

R1 R2 R3 Experimental

Value

Theoretical Value

in mA

1 100 100 100

2 100 200 100

3 100 300 100

4 100 400 100

5 100 500 100

6 100 600 100

7 100 700 100

8 100 800 100

9 100 900 100

10 100 1000 100

Result:

Thevenin’s and Norton’s theorems are verified by arranging suitable electrical circuits.

Thevenin’s voltage and Norton’s current are also measured and they are in good agreement

with the calculated values.

4. Measurement of voltage (ac and dc) and frequency using CRO

Aim :

To measure the alternating voltage (AC) , direct voltage (DC) and frequency of the given

AC signal.

Apparatus :

CRO (Cathode Ray Oscilloscope), battery eliminator, AFO (Audio frequency oscillator or

Function generator ), multimeter and connecting wires etc.

Block diagram of CRO :

Measurement of Direct Voltage (DC) :

Observation table to measure DC voltage :

S.No. Length of vertical

line in X cm

Reading on

Volts/Div

Scale (N)

Measured voltage

Vo= X.N in volts

Actual DC voltage

Vi in volts

1 0.5

2 1.0

3 1.5

4 2.0

5 2.5

6 3.0

Measurement of Alternating Voltage (AC) :

Observation table to measure AC voltage :

S.No. Length of

vertical line

in X cm

Reading on

Volts/Div

Scale (N)

Peak to

Peak voltage

VPP=X.N

in volts

Peak

voltage

in Volts

RMS

voltage

in volts

Actual

AC

voltage Vi

in volts

1 0.5

2 1.0

3 1.5

4 2.0

5 2.5

6 3.0

Measurement of frequency :

Observation table to measure frequency :

S.No. Actual

frequency

in Hz

Distance

between two

successive

peaks X in cm

Reading on

Time/Div

Scale (N)

Time period

T=X.N msec

Measured

frequency

Hz

1 50

2 100

3 150

4 200

5 250

6 300

Result :

By using CRO the alternating voltage, direct voltage and frequency of the given AC signal

are measured and the resultant values are in good agreement with the calculated values.

5. Verification of Maximum power transfer theorem

Aim :

To state and verify maximum power transfer theorem by arranging simple electric circuit.

Apparatus :

Batteries 1.5V – (2), Resostpr 100Ω –(1), Resistance box – (1), multimeter and connecting

wires etc.

Circuit diagram :

Model Graph :

Calculation :

Maximum Power Pmax =

Observation Table :

S.No. Load Resistance RL in Ω Voltage across the load

resistance VL in VoltsPower in mW

1 10

2 20

3 30

4 40

5 50

6 60

7 70

8 80

9 90

10 100

11 110

12 120

13 130

14 140

15 150

16 160

17 170

18 180

19 190

20 200

Result :

Maximum power is delivered when load resistance is equal to the internal resistance of the

source.

Maximum power Pmax = ________________

Value of Resistance at maximum power

From graph

Actual value 100Ω

6. Frequency response of CR circuit

Aim :

To study the frequency response of high pass and low pass filters and also to determine the

cutoff frequency by constructing suitable CR circuits.

Apparatus :

Function generator -1, multimeter, capacitors and resistors of suitable values, connecting

wires etc.

Design :

Cutoff frequency Where f0 = 100Hz, C=0.1μF

Now =

Circuit diagram for High pass filter :

Model Graph :

Observation table for high pass filter : Input voltage Vi = 1V

S.No. Frequency in Hz Output voltage

V0 in voltsGain =

1 20

2 30

3 40

4 50

5 60

6 70

7 80

8 90

9 100

10 200

11 300

12 400

13 500

14 600

15 700

16 800

17 900

18 1000

19 2000

20 3000

21 4000

22 5000

23 6000

24 7000

25 8000

26 9000

27 10000

Design :

Cutoff frequency Where f0 = 500Hz, C=0.1μF

Now =

Circuit diagram for Low pass filter :

Model Graph :

Observation table for low pass filter : Input voltage Vi = 1V

S.No. Frequency in Hz Output voltage

V0 in voltsGain =

1 20

2 30

3 40

4 50

5 60

6 70

7 80

8 90

9 100

10 200

11 300

12 400

13 500

14 600

15 700

16 800

17 900

18 1000

19 2000

20 3000

21 4000

22 5000

23 6000

24 7000

25 8000

26 9000

27 10000

Result :

The frequency response of low pass and high pass filters is studied by arranging suitable

CR circuits. Also the cutoff frequencies are found experimentally and are tabulated below.

S.No. Filter type Cutoff frequency in Hz

Theoretical value Experimental value

1 High pass filter 100

2 Low pass filter 500

7. Conversion of basic meter into voltmeter

Aim :

To study the given basic meter into voltmeter of required range by determining its internal

resistance.

Apparatus :

Galvanometer, battery eliminator, keys -2, commutator, resistance box, multimeter,

connecting wires etc.

Circuit diagram 1 :

Formulas :

Maximum current where E = 1.2V

R = Resistance for full scale deflection

Rm = Internal resistance of the meter

Series Resistance where V= Range of voltmeter

Im = maximum current

Rm = Internal resistance of the meter

Observation table 1: To find internal resistance

S.No. Resistance in R for full scale deflection in ohms

Deflection in galvanometer in divisions

Resistance in resistance box for half scale deflection in ohms

Left Right Mean Left Right Left Right Mean

1 50 50

2 40 40

3 30 30

Maximum current where E = 1.2V

Series resistance

Circuit diagram 2 :

Observation table 2:

S.No. Resistance in Ω Voltage measured with

converted meter

Calculated voltage Voltage measured

with multimeter

in voltsP Q Deflections

in division

Voltage

in volts

1 1000 50 5

2 1000 40 4

3 1000 30 3

4 1000 20 2

5 1000 10 1

Result :

The given basic meter is connected into voltmeter of range = _________

The internal resistance of the meter Rm =___________

The maximum current passing through the meter Im = __________________

The series resistance require to convert given basic meter into voltmeter is Rs = _________

8. VI characteristics of PN junction diode

Aim :

i) To study the VI characteristics of PN junction diode in forward and reverse bias

conditions.

ii) To determine the resistance of diode in both forward and reverse bias.

iii) To find threshold voltage of the diode.

Apparatus :

PN junction diode, Battery eliminator, resistance box, resistor 100Ω, voltmeters (0-1V,

0-10V), milliammeter (0-10mA), milliammeter (0-1mA), connecting wires, multimeter etc.

Circuit diagram for forward bias :

Observation Table 1:

S.No. Input voltage

Vi in volts

Voltage across the diode

Vd in volts

Current through the diode

Id in mA

1 0.1

2 0.2

3 0.3

4 0.4

5 0.5

6 0.6

7 0.7

8 0.8

9 0.9

10 1.0

Circuit diagram for reverse bias :

Observation Table 2:

S.No. Input voltage

Vi in volts

Voltage across the diode

Vd in volts

Current through the diode

Id in mA

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

Model graph :

Result :

The characteristics of the given diode are studied both in forward and reverse bias

conditions. Also, the forward resistance and threshold voltage are determined from the

graph and they are tabulated below.

Parameter Experimental value Theoretical value

Resistance in forward bias,

Rf in Ω

≈ 100 Ω

Resistance in reverse bias,

Rr in Ω

≈ ∞

Threshold voltage VT in

volts

≈ (0.3 – 0.4)

9. VI characteristics of Zener diode

Aim :

To study the VI characteristics of zener diode in forward and reverse bias conditions and

also to determine its threshold and breakdown voltages.

Apparatus :

zener diode, Battery eliminator, resistance box, resistor 100Ω, voltmeters (0-1V, 0-10V),

milliammeter (0-10mA), connecting wires, multimeter etc.

Circuit diagram for forward bias :

Observation Table 1:

S.No. Input voltage

Vi in volts

Voltage across the diode

Vd in volts

Current through the diode

Id in mA

1 0.1

2 0.2

3 0.3

4 0.4

5 0.5

6 0.6

7 0.7

8 0.8

9 0.9

10 1.0

Circuit diagram for reverse bias :

Observation Table 2:

S.No. Input voltage

Vi in volts

Voltage across the diode

Vd in volts

Current through the diode

Id in mA

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

Model graph :

Result :

The characteristics of the given diode are studied both in forward and reverse bias

conditions. Also, the forward resistance and threshold voltage are determined from the

graph and they are tabulated below.

Parameter Experimental value Theoretical value

Resistance in forward bias,

Rf in Ω

≈ 100 Ω

Resistance in reverse bias,

Rr in Ω

≈ ∞

Threshold voltage VT in

volts

≈ (0.3 – 0.4)

10. Zener diode voltage and current regulation

characteristics

Aim: To study the voltage and current regulation characteristics of a zener diode.

Apparatus: Zener diode, battery eliminator, voltmeter (0-10V), milliammeter (0-20mA),

bread board, connecting wires etc.

Circuit diagram for voltage regulation :

Observation Table :

S.No. Input voltage Vi in volts Output voltage Vo in volts

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

Model graph :

Circuit diagram for Current regulation :

Observation Table:

S.No. Current through the zener

diode IL in mA

Output voltage Vo in volts

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

11 11

12 12

13 13

14 14

15 15

16 16

17 17

18 18

19 19

20 20

Model graph:

Result:

The voltage and current regulation characteristics of a given zener diode are studied and

the graphs are plotted.