laboratory material ee0211 electrical … contents sl.no. name of the experiments page no. 1...

1

LABORATORY MATERIAL

EE0211 – ELECTRICAL CIRCUITS LAB

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING FACULTY OF ENGINEERING & TECHNOLOGY

SRM UNIVERSITY, Kattankulathur – 603 203

2

CONTENTS

Sl.No. Name of the Experiments Page No.

1 Verification of Kirchoff’s laws 3

2 Verification of Superposition theorem 6

3 Verification of Thevenin’s & Norton’s Theorem 9

4 Verification of Maximum Power Transfer theorem 15

5 Power measurement in 3 phase unbalanced circuits 19

6 Power measurement in 3 phase balanced circuits 20

7 Power measurement using 3 voltmeter & 3 ammeter

method

22

8 Circuit analysis using CRO 26

9 Circuit transients by digital simulation 28

10 Study of resonance 30

3

Experiment No. 1

Date :

VERIFICATION OF KIRCHHOFFS LAWS

Aim:

To verify Kirchhoff’s current law and Kirchhoff’s voltage law for the given circuit.

Apparatus Required:

Sl.No. Apparatus Range Quantity

1 RPS (regulated power supply) (0-30V) 2

2 Resistance 330, 220 1k 6

3 Ammeter (0-30mA)MC 3

4 Voltmeter (0-30V)MC 3

5 Bread Board & Wires -- Required

Statement:

KCL: The algebraic sum of the currents meeting at a node is equal to zero.

KVL: In any closed path / mesh, the algebraic sum of all the voltages is zero.

Precautions:

1. Voltage control knob should be kept at minimum position.

2. Current control knob of RPS should be kept at maximum position.

Procedure for KCL:

1. Give the connections as per the circuit diagram.

2. Set a particular value in RPS.

3. Note down the corresponding ammeter reading

4. Repeat the same for different voltages

Procedure for KVL:


2. Set a particular value in RPS.

3. Note all the voltage reading

4. Repeat the same for different voltages

Circuit - KCL

4

Circuit - KVL

KCL - Theoretical Values:

Sl.

No.

Voltage

E

Current I1 = I2 + I3

I1 I2 I3

Volts mA mA mA mA

1 5 5.68 3.12 2.56 5.68

2 10 11.3 6.18 5.12 11.3

3 15 17.05 9.37 7.68 17.05

4 20 22.73 12.49 10.24 22.075

5 25 28.42 15.62 12.68 28.42

KCL - Practical Values:

Sl.

No.

Voltage

E

Current I1 = I2 + I3

I1 I2 I3

Volts mA mA mA mA

1 5 5.6 3.1 2.2 5.3

2 15 17.2 9.4 7.6 17

3 25 28 15.6 12.7 28.3

KVL – Theoretical Values

Sl.No. RPS Voltage KVL

E1 = V1 + V2 E1 E2 V1 V2 V3

V V V V V V

1 5 5 0.58 4.41 0.583 4.99

2 10 10 1.16 8.83 1.17 9.99

3 15 15 1.75 13.2 1.75 14.95

4 20 20 2.33 17.67 2.33 20

5 25 25 2.913 22.08 2.915 24.993

5

KVL - Practical Values

Sl.No. RPS Voltage KVL

E1 = V1 + V2 E1 E2 V1 V2 V3

V V V V V V

1 5 5 0.6 4.4 0.56 5

2 10 10 1.13 8.83 1.19 9.96

3 15 15 1.72 13.20 1.78 14.92

Model Calculations:

Result:

Thus Kirchoff’s voltage load and Kirchoff’s current law verified both theoretically

and practically.

6

Experiment No. 2

Date :

VERIFICATION OF SUPERPOSITION THEOREM

Aim:

To verify the superposition theorem for the given circuit.

Apparatus Required:



2 Ammeter (0-10mA) 1

3 Resistors 1k, 330, 220 3

4 Bread Board -- --

5 Wires -- Required

Statement:

Superposition theorem states that in a linear bilateral network containing more than

one source, the current flowing through the branch is the algebraic sum of the current flowing

through that branch when sources are considered one at a time and replacing other sources by

their respective internal resistances.

Precautions:

1. Voltage control knob should be kept at manimum position

2. current control knob of RPS should be kept at maximum position

Procedure:

1. Give the connections as per the diagram.

2. Set a particular voltage value using RPS1 and RPS2 & note down the ammeter

reading

3. Set the same voltage in circuit I using RPS1 alone and short circuit the terminals

and note the ammeter reading.

4. Set the same voltage in RPS2 alone as in circuit I and note down the ammeter

reading.

5. Verify superposition theorem.

7

CIRCUIT - 1

CIRCUIT - 2

CIRCUIT - 3

TABULAR COLUMN

Theoretical Values

RPS Ammeter Reading (I)

mA 1 2

Circuit – 1

10 V 10 V I = 8.83

Circuit – 2

10 V 0 V I’= 3.5

Circuit – 3

0 V 10 V I”= 5.3

I = I’ I” = 8.83

Practical Values

RPS Ammeter Reading (I)

mA 1 2

Circuit – 1

10 V 10 V I = 8.5

Circuit – 2

10 V 0 V I’= 3.5

Circuit – 3

0 V 10 V I”= 5

I = I’ I” = 8.5 mA

= 3.5 + 5 = 8.5 mA

8

Model Calculations:

Result:

Superposition theorem have been verified theoretically and practically.

9

Experiment No. 3

Date :

VERIFICATION OF THEVENIN’S THEOREM

Aim:

To verify Thevenin’s theorem and to find the full load current for the given circuit.

Apparatus Required:



2 Ammeter (0-10mA) 1

3 Resistors 1K, 330 3,1

4 Bread Board -- Required

5 DRB -- 1

Statement:

Any linear bilateral, active two terminal network can be replaced by a equivalent

voltage source (VTH). Thevenin’s voltage or VOC in series with looking pack resistance RTH.

Precautions:

1. Voltage control knob of RPS should be kept at minimum position.

2. Current control knob of RPS should be kept at maximum position

Procedure:

1. Connections are given as per the circuit diagram.

2. Set a particular value of voltage using RPS and note down the corresponding

ammeter readings.

To find VTH

3. Remove the load resistance and measure the open circuit voltage using multimeter

(VTH).

To find RTH

4. To find the Thevenin’s resistance, remove the RPS and short circuit it and find the

RTH using multimeter.

5. Give the connections for equivalent circuit and set VTH and RTH and note the

corresponding ammeter reading.

6. Verify Thevenins theorem.

Theoretical and Practical Values

E(V) VTH(V) RTH() IL (mA)

Circuit - I Equivalent

Circuit

Theoretical

10 5 495 3.34 3.34

Practical

10 4.99 484 3.3 3.36

10

Circuit - 1 : To find load current

To find VTH

To find RTH

Thevenin’s Equivalent circuit:

11

Model Calculations:

Result:

Hence the Thevenin’s theorem is verified both practically and theoretically

12

Experiment No. 4

Date :

VERIFICATION OF NORTON’S THEOREM

Aim:

To verify Norton’s theorem for the given circuit.

Apparatus Required:


1 Ammeter (0-10mA) MC

(0-30mA) MC

1

1

2 Resistors 330, 1K 3,1

3 RPS (0-30V) 2

4 Bread Board -- 1

5 Wires -- Required

Statement:

Any linear, bilateral, active two terminal network can be replaced by an equivalent

current source (IN) in parallel with Norton’s resistance (RN)

Precautions:



Procedure:

1. Connections are given as per circuit diagram.

2. Set a particular value in RPS and note down the ammeter readings in the original

circuit.

To Find IN:

3. Remove the load resistance and short circuit the terminals.

4. For the same RPS voltage note down the ammeter readings.

To Find RN:

5. Remove RPS and short circuit the terminal and remove the load and note down

the resistance across the two terminals.

Equivalent Circuit:

6. Set IN and RN and note down the ammeter readings.

7. Verify Norton’s theorem.

13

To find load current in circuit 1:

To find IN

To find RN

Norton’s equivalent circuit

Constant current source

14

Theoretical and Practical Values

E

(volts)

IN

(mA)

RN

()

IL (mA)

Circuit - I Equivalent

Circuit

Theoretical

Values

10 10.10 495 334 3.34

Practical

Values

10 10.4 485 3.4 4

Model Calculations:

Result:

Norton’s was verified practically and theoretically

15

Experiment No. 5

Date :

VERIFICATION OF MAXIMUM POWER TRANSFER

THEOREM

Aim:

To verify maximum power transfer theorem for the given circuit

Apparatus Required:


1 RPS (0-30V) 1

2 Voltmeter (0-10V) MC 1

3 Resistor 1K, 1.3K, 3 3

4 DRB -- 1

5 Bread Board & wires -- Required

Statement:

In a linear, bilateral circuit the maximum power will be transferred to the load when

load resistance is equal to source resistance.

Precautions:



Procedure:

Circuit – I

1. Connections are given as per the diagram and set a particular voltage in RPS.

2. Vary RL and note down the corresponding ammeter and voltmeter reading.

3. Repeat the procedure for different values of RL & Tabulate it.

4. Calculate the power for each value of RL.

To find VTH:

5. Remove the load, and determine the open circuit voltage using multimeter (VTH)

To find RTH:

6. Remove the load and short circuit the voltage source (RPS).

7. Find the looking back resistance (RTH) using multimeter.

Equivalent Circuit:

8. Set VTH using RPS and RTH using DRB and note down the ammeter reading.

9. Calculate the power delivered to the load (RL = RTH)

10. Verify maximum transfer theorem.

16

Circuit - 1

To find VTH

To find RTH

Thevenin’s Equation Circuit

17

Power VS RL

Circuit – I

Sl.No. RL () I (mA) V(V) P=VI (watts)

1

2

3

4

5

6

7

8

200

400

600

800

1200

1300

1400

1500

1.3

1.2

1.1

1

0.80

0.77

0.74

0.71

0.27

0.481

0.638

0.771

1.083

1.024

0.998

0.968

0.26

0.53

0.707

0.771

0.866

0.788

0.738

0.687

To find Thevenin’s equivalent circuit

VTH (V) RTH () IL (mA) P (milli watts)

Theoretical

Value

2002 1320 0.758 0.759

Practical Value

2 1306 0.77 0.77

18

Model Calculations:

Result:

Thus maximum power theorem was verified both practically and theoretically

19

Experiment No. 6

Date :

THREE PHASE POWER MEASUREMENT (TWO WATTMETER METHOD)

Aim:

To measure the 3-phase active and reactive power by 2 – wattmeter method for (i)

resistance load (ii) inductive load

Apparatus Required:


1 Voltmeter (0-600V) MI 1

2 Ammeter (0-20A) MI 1

3 Wattmeter 600V, 10A, UPF 2

4 Wattmeter 600V, 10A, LPF 2

Precautions:

THE TPST switch must be kept open initially.

Load must not be applied while starting.

Procedure:

(i) – Resistive load


2. Give the supply by closing TPST switch.

3. Vary the resistance load and note down the corresponding readings.

(ii) Inductive load


2. Give the supply by closing the TPST switch

3. Vary the inductive load and note down the corresponding readings.

for inductive load

20

for resistive load

Formulae Used:

1. Real power = w1 + w2

2. Reactive power = )(3 21 ww

3. Tan = 21

21 )(3

ww

ww

4. Power factor = cos

Two Wattmeter Method : Resistive Load

V

(volt)

I

(A)

MF =

Wattmeter

Reading (W1)

MF =

Wattmeter

Reading (W2)

Power

Cos OBS

(watt)

ACT =

OBS X

MF

(watt)

OBS

(watt)

ACT=OBS

x MF

(watt)

Real

Power

(watt)

Reactive

power

(watt)

460

460

460

460

460

460

460

460

460

0

1.8

3.7

4.6

5.5

6.3

7.2

8.1

9

0

70

160

200

240

280

320

350

390

0

560

1280

1600

1920

2240

2560

2800

3120

0

90

180

210

250

290

330

370

410

0

720

1440

1680

2000

2320

2640

2960

3280

0

1280

2720

3280

3920

4560

5200

5760

6400

0

-277.12

-277.12

-138.56

-138.56

-138.56

-138.56

-277.12

-277.12

0

0.977

0.9949

0.999

0.9

0.993

0.996

0.9988

0.990

21

Two Wattmeter Method : Inductive Load

V

(volt)

I

(A)

MF =

Wattmeter

Reading (W1)

MF =

Wattmeter

Reading (W2)

Power

Cos OBS

(watt)

ACT =

OBS x

MF

(watt)

OBS

(watt)

ACT=OBS

x MF

(watt)

Real

Power

(watt)

Reactive

power

(watt)

410

410

410

410

410

410

1

2

3

4

5

6

11

15

28

43

78

95

89

120

140

344

624

760

26

32

53

80

106

132

208

256

424

640

848

1056

296

376

564

984

1472

1816

-554.26

-443.41

-734.39

-1108.51

-1461.78

-1829.05

0.351

0.647

0.609

0.664

0.708

0.705

Model Calculations:

Result:

Thus power for three phase power supply was measured using 2 wattmeter method.

22

Experiment No. 7

Date :

POWER MEASUREMENT BY 3 - VOLTMETER

Aim:

To measure the power in an inductive circuit, Eg: transformer, by 3- voltmeter

method.

Apparatus Required:


1 Ammeter (0-5A) MI 1

2 Voltmeter (0-150V) MI

(0-300V) MI

2

1

3 Transformer 230V/115V, 1KVA 1

4 Auto Transformer - -

5 Auto Transformer - 1

6 Rheostat 100 1

Precaution:

1. The DPST switch must be kept open initially.

2. The auto transformer must be kept at minimum potential position

3. The rheostat must be kept at maximum resistance position.

Procedure:


2. Adjust the auto transformer, to bring the rated voltage of the transformer

3. Note down the transformer and voltmeter readings.

4. Vary the rheostat for different values and note down the corresponding meter

readings.

3 – Voltmeter Method

Sl.

No.

I

(amp)

Vs

(volts)

VR

(volts)

VL

(volts)

P

(watts) Cos

1

2

3

4

5

6

0.2

0.6

0.8

1

1.1

1.2

150

150

150

150

150

150

15

54

73

86

90

95

136

120

120

110

105

100

25.193

21.99

15.18

17.46

20.625

21.99

0.82

0.293

0.158

0.158

0.178

0.182

23

Formulae Used:

1. Power (P) = R

VVV LRS

2

222 watts

R = VR / I

2. Cos = Le

LRS

VV

VVV

2

222

Model Calculations:

Result:

The power was measured for given circuit using 3 voltmeter method

24

Experiment No. 8

Date :

POWER MEASUREMENT BY 3 - AMMETER

Aim:

To measure the power in an inductive circuit, Eg: transformer, by 3- ammeter method.

Apparatus Required:


1 Ammeter (0-2A) MI

(0-5A) MI

2

1

2 Voltmeter (0-150V) MI 1

3 Auto transformer - 1

4 Transformer 230V/115V

1KVA, 1

1

5 Rheostat 100 / 4A 1

Precaution

1. The DPST switch must be kept open initially

2. The autotransformer should be kept at minimum potential position

3. The rheostat should be kept at maximum resistance position

Procedure:

1. Give the connections as per the circuit diagram

2. Adjust the auto transformer, to bring the rated voltage of the transformer

3. Note down the ammeter and voltmeter readings.

4. Vary the rheostat for different values and note

3 – Voltmeter Method

Sl.

No.

V

(volts)

Is

(amp)

IR

(amp)

IL

(amp)

R

(ohm)

P

(watts) Cos

1

2

6

4

5

6

115

115

115

115

115

115

0.75

0.85

0.95

1.05

1.15

1.25

0.54

0.6

0.7

0.8

0.9

1

0.48

0.48

0.48

0.48

0.48

0.46

213

191.67

164.3

143.7

127.7

0.46

4.31

912.6

14.9

16.6

18

20.1

0.07

0.22

0.57

0.3

0.32

0.37

25

Formulae Used:

Power (P) = 222

2 LRS IIIR

R = V / IR

Power factor cos = LR

LRS

II

III

2

222

Model Calculations:

Result:

Thus power was measured using 3 ammeter method

26

Experiment No. 9

Date :

CIRCUIT ANALYSIS USING CRO

Aim:

To measure voltage and current and also to study the phase relationship between

supply voltage and current in series RC circuit.

Apparatus Required:


1 Function generator 1

2 DMM 1

3 Resistor 200 1

4 Capacitor 1 F 1

5 CRO 1

Procedure:

1. Connections are given as per the circuit diagram.

2. In the function generator, select “SINE WAVE” as the output and set the

frequency to 200 Hz.

3. Adjust the amplitude knob of the function generator until the waveform on the

oscilloscope shows 2 Vp.

4. Record the peak voltage across the resistor using CRO.

5. Calculate from t.

6. Draw the waveform for VS, VR.

Circuit Diagram:

27

Sl.No. Frequency

(Hz)

VR

V

T

(ms) t

(ms)

deg

1 200 0.4 5 0.3 21.6

(leading

Sl.No. Frequency

(Hz)

VR

V

T

(ms) t

(ms)

deg

1 0.32 1.6mA 1.2 750 7.95

Result:

The phase relationship between supply voltage and current in series RC circuit is

studied and also the voltage and current are increased practically.

28

Experiment No. 10

Date :

CIRCUIT TRANSIENTS BY SIMULATION IN RL

CIRCUIT

Aim:

To simulate the RL circuit using Pspice software and to study the transient response

Circuit Diagram:

Simulation Parameter:

Vdc = 10 volts, R1 = 50 ohms, L = 100mH

29

Simulation Output:

1. Transient L wave form

2. Transient R wave form

Result:

Simulation of the RL transient circuit was done

30

Experiment No. 11

Date :

STUDY OF RESOURCE

Aim:

To study series and parallel resource in AC circuit

Series Resource:

An RLC circuit is said to be at re source when voltage and current are in phase with

each other and power factor is unity.

z

CL XXjRZ )(

At series resource XL = XC

Z = R

XL = XC

C

L

1

CL

12

LC

frn

1)2( 2

C

rL

f2

1

Power factor Z

Rcos

Q - factor = V

V

V

V LC

Parallel Resonance:

Parallel AC circuit is said to be at resource when voltage and current are in phase with

each other and power factor is unity.

(i) ideal parallel circuit Cu L

f2

10

(ii) Practical circuit - I 2

2

0

1

2

1

L

R

Lf

Cu

(iii) Practical circuit – II

CLR

CLR

If

L

L

Cu/)(

/)(

2

12

2

0

laboratory material ee0211 electrical … contents sl.no. name of the experiments page no. 1...

Documents