Department of Electrical and Electronics Engineering CIRCUITS LAB.pdfMaximun Power Transfer theorem It states that, maximum power will be transferred from source to load when the load

POTTI SRIRAMULU CHALAVADI MALLIKARJUNA RAO.

COLLEGE OF ENGINEERING & TECHNOLOGY (Affiliated to JNTU, Kakinada & Approved by AICTE New Delhi)

KOTTHA PETA, VIJAYAWADA - 520001.

Department of Electrical and Electronics Engineering

**************************************************

********

ELECTRICAL CIRCUITS LABORATORY MANUAL

II B.Tech I Semester

Electrical & Electronics Engineering

Name: ……………………………………………………......

Roll Number: ……………………………………………....

ELECTRICAL CIRCUITS LAB (R16)

DEPT. OF EEE, PSCMRCET

ACKNOWLEDGEMENT

It is one of life’s simple pleasures to say thank you for all the help that one has extended their

support. I wish to acknowledge and appreciate EEE Faculty for their sincere efforts made towards

developing the Electrical Circuits Lab manual. I wish to thank students for their suggestions which are

considered while preparing the lab manuals.

I am extremely indebted to Sri. Dr.K.Nageswara Rao , Principal and Sri. Y.Rajendra babu,

HOD of Electrical and Electronics Engineering, PSCMRCET for their valuable inputs and sincere

support to complete the work.

Specifically, I am grateful to the Management for their constant advocacy and incitement.

Finally, I would again like to thank the entire faculty in the Department and those people who

directly or indirectly helped in successful completion of this work.



DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

2017-2018

EVALUATION PATTERN

FOR ELECTRICAL and ELECTRONICS

LABORATORY

The Electrical and Electronics lab evaluation can be broadly classified as per the contents

Internal Assessment: 25 Marks

1. Two internals will be conducted for laboratory assessment.

2. Day-to-day work in the laboratory shall be evaluated for 15 marks.

3. Internal examination for practical shall be evaluated for 10 marks conducted by the

Concerned laboratory teacher.

End Examination Assessment: 50 Marks

1. The end examination conducted for 50 marks with duration of 3 hours.

2. The end examination shall be conducted with external examiner and laboratory teacher.

The external examiner shall be appointed from the cluster of colleges as decided by the

University examination branch.



LIST OF EXPERIMENTS

SL.NO EXPERIMENT NAME PAGE NO

1. Verification of Thevenin’s And Norton’s Theorems 01

2. Verification of Superposition Theorem And Maximum Power transfer Theorem 08

3. Compensation Theorem 15

4. Verification of Reciprocity& Millimann’s theorems 19

5. Determination of Self, Mutual Inductances And Coefficient of Coupling 27

6. Resonance In Series And Parallel RLC Circuits 31

7. Determination of Z And Y Parameters 36

8. Transmission And Hybrid Parameters 41

9. Measurement of 3-Phase Power By Using Two Wattmeter Method 46

10. Determination of Parameters of Choke Coil 49



INDEX

S.No Date Name of the Experiment Page Remarks Sign



CYCLE –I

1. Verification of Thevenin’s And Norton’s Theorems

2. Verification of Superposition Theorem And Maximum Power transfer Theorem

3. Compensation Theorem

4. Verification of Reciprocity& Millimann’s theorems

5. Determination of Self, Mutual Inductances And Coefficient Of Coupling

CYCLE-II

1. Resonance In Series And Parallel RLC Circuits

2. Determination of Z And Y Parameters

3. Transmission And Hybrid Parameters

4. Measurement of 3-Phase Power By Using Two Wattmeter Method

5. Determination of Parameters of Choke Coil


DEPT. OF EEE, PSCMRCET Page 1

EXP. NO. DATE:

VERIFICATION OF THEVENIN’S AND NORTON’S THEOREMS

AIM: To verify Thevenin’s & Norton’s theorems for the given circuit.

STATEMENTS:

Thevenin’s theorem

It states that any linear, active network with two open terminals can be replaced by an equivalent circuit

consisting of Thevenin’s equivalent voltage source Vth in series with Thevenin’s equivalent resistance Rth.

Where Vth is the open circuit voltage across the two terminals and Rth is the resistance seen from the same

two terminals by replacing all the sources by their internal resistances.

Norton’s theorem

It states that any linear, active network with to open terminals can be replaced by an equivalent circuit

consisting of Norton’s equivalent current source IN in parallel with Norton’s equivalent resistance RN.

Where IN is the short circuit current through the two terminals and RN is the resistance seen from the same

two terminals by replacing all the sources by their internal resistances.

APPARATUS:

S. No Name of the apparatus Range Type Quantity

1 Dual channel R.P.S (0 – 30)V - 1No

2 Voltmeter (0-10)V MC 1No

3 Ammeter (0-10) m A MC 1No

4 Decade Resistance Box (0-111.11K) - 1No

5 Resistors

6 Bread board - - 1No

7 Connecting wires - - Required number

PROCEDURE:

Thevenin’s Theorem

1. Connect the circuit as per the circuit diagram (6.1) and set the R.P.S output voltage to 10V.

2. Note down the current ( IL )through the load terminals AB and disconnect the circuit.


4. Note down the voltage across the load terminals AB which gives Vth and disconnect the circuit.

5. Connect the circuit as per the fig (6.3) and set the R.P.S output voltage to say V=5V.

6. Note down the current supplied by the source I, the ratio of V and I gives Rth.

7. Connect the circuit as per the circuit diagram (6.4) and set the R.P.S output voltage to VTh.

8. Note down the current IL1 through the load terminals AB and disconnect the circuit.



Norton’s Theorem


2. Note down the current through the load terminals AB which gives IN and disconnect the circuit.

3. Connect the circuit as per the fig (6.6) and set the R.P.S output voltage to say V=5V.

4. Note down the current supplied by the source I, the ratio of V and I gives RN.

5. Connect the circuit as per the circuit diagram (6.7) and set the current source to IN mA.

6. Note down the current IL1 through the load terminals AB and disconnect the circuit.

PRECAUTIONS:

1. Initially keep the RPS voltage knob in zero volt position.

2. Set the ammeter pointer at zero position.

3. Take the readings with out parallax error.

4. Avoid loose connections.

5. Do not short-circuit the output terminals of the R.P.S.



THEORETICAL CALCULATIONS: Circuit diagram To find load current IL:

Circuit diagram to find Vth:

Circuit diagram to find Rth:

Circuit to find load current using Thevenin’s equivalent circuit:



CONNECTION DIAGRAM TO FIND LOAD CURRENT IL: Tabular Column:

Fig ( 6. 1)

Circuit diagram to find Vth:

Fig (6. 2)

S. No Applied voltage,VS ( volt) Thevenin’s voltage,Vth(volt)

CONNECTION DIAGRAM TO FIND RTH:

Fig (6. 3)

S. No Applied voltage,V ( volt) Current, I (mA) Rth=V/I

S. No Applied voltage,VS ( volt) Current,IL(mA)



Circuit to find load current using Thevenin’s equivalent circuit:

fig (6.4)

THEORETICAL CALCULATIONS:

Circuit diagram to find I N:

Circuit diagram to find RN:

S.

No

Thevenin’s

voltage,Vth(volt)

Rth

(ohms) Current, I L

1(mA)



Circuit to find load current using Norton’s equivalent circuit:

1 N

L N

N L

RI =I ×

R +R

Circuit diagram to find I N:

Fig (6. 5)

S. No Applied voltage,VS ( volt) Norton’s current, IN (mA)

Circuit diagram to find RN:

Fig (6. 6)

S. No Applied voltage,V ( volt) Current, I (mA) RN=V/I



Circuit to find load current using Norton’s equivalent circuit:

Fig (6.7)

S. No Norton’s

Current,(IN)

RN

(ohms) Current, I L

1(mA)

OBSERVATIONS:

Thevenin’s Theorem:

S.No Parameter Theoretical

values

Practical

values

1 Vth

2 Rth

3 Load current IL= IL1=

Norton’s Theorem:

S.No Parameter Theoretical

values

Practical

values

1 IN

2 RN

3 Load current IL= IL1=

RESULT:



EXP. NO. DATE:

VERIFICATION OF SUPERPOSITION THEOREM AND MAXIMUM

POWERTRANSFER THEOREM

AIM: To verify Superposition Theorem and Maximum Power Transfer Theorem for the given circuit.

STATEMENTS:

Super position theorem

In any linear, bilateral, multi source network the response in any element is equal to the algebraic sum

of the responses obtained by each source acting separately while all other sources are set equal to zero.

Maximun Power Transfer theorem

It states that, maximum power will be transferred from source to load when the load impedance is the

complex conjugate of source impedance in AC and in DC circuits load resistance in equal to source

resistance.

APPARATUS:


1

Dual channel regulated

power supply (0 – 30V) - 1No

2 Voltmeter (0-10)V MC 1No

3 Ammeter (0 – 10) mA MC 1No

4 Decade Resistance Box (0-111.11) K - 1No

5 Resistors -





PROCEDURE:

Super position theorem

1. Connect the circuit as per the fig (4.1).

2. Adjust the output voltage of sources X and Y to 20V and 5V respectively (RPS output).

3. Note down the response ( IL) through the branch of interest i.e. AB.

4. Now set the 5V source Y to 0V and note down the current (ILl) through the branch AB as per

Fig(4.2)

5. Now set the 20V source X to 0V and source Y to 5V note down the response ( ILll) through the

branch AB as per Fig(4.3)

6. Disconnect the circuit.

Maximun Power Transfer theorem

1. Connect the circuit as per the fig (5.1) and set the R.P.S output voltage to 10V.

2. By Varying the resistance in D.R.B. in steps note down the current through the load and

calculate the power absorbed by the load (PL) for each step using the formula PL=IL2

RL.


4. Draw the graph by taking RL on x-axis and PL on y-axis and note down the value of maximum

power i.e; Pmax and corresponding load resistance RL

PRECAUTIONS:

1. Initially keep the RPS output voltage knob in zero volt position.




5. Avoid short circuit of RPS output terminals.



THEORETICAL CALCULATIONS FOR SUPERPOSITION THEOREM:

When both the sources are acting:

When 5V source is acting;

When 20V source is acting;



CONNECTION DIAGRAM WHEN BOTH THE SOURCES ARE ACTING:

Fig(4.1)

Connection diagram When 20V source is acting; Tabular Column:

Fig (4.2)

Connection diagram When 5V source is acting Tabular Column:

Fig (4.3)

S.No

Applied Voltage Current

IL

(mA) V1

(Volts)

V2

(Volts)

S. no

Applied

voltage

(V1) Volt

CurrentIL1

(mA)

S. No Applied voltage

(V2) Volt

CurrentIL11

(mA)



THEORETICAL CALCULATIONS FOR MAXIMUM POWER TRANSFER THEOREM:

Circuit diagram to find Rth : Circuit diagram to find Vth :

Thevenin’s Equivalent circuit:

Output power P0 = ILI 2

RL=Vm2

/(RTh+RL)2*RL=(VTh/4RL

2)*RL=VTh

2/4RL



CONNECTION DIAGRAM FOR MAXIMUM POWER TRANSFER THEOREM:

Fig (5.1)

:

TABULAR COLUMN:

S.no IL(mA) RL() PL= IL

2 RL(mW)



Model Graph for Maximum Power Transfer Theorem:

OBSERVATIONS:

Superposition Theorem:

Maximum Power Transfer Theorem:

RESULT:

S.No Load current Theoretical Value Practical Value

1 When both sources are acting, IL

2 When only source V1 is acting, ILI

3 When only source V2 is acting,ILII

S.No

Parameter

Theoretical Value Practical Value

1 RL

2 Pmax



EXP. NO. DATE:

COMPENSATION THEOREM

AIM: To verify compensation theorem for the given circuit.

STATEMENT:

Compensation theorem:

It states that in a linear bilateral network any element may be replaced by a voltage source of a

magnitude equal to the current passing through the element multiplied by the value of its resistance

(provided that the current and voltage in the other parts of the circuit remain unaltered).

APPARATUS:

PROCEDURE:

1. Connect the circuit as per the fig (1).

2. Adjust the output voltage of source to an appropriate value (say 10V).

3. Note down I1 by using ammeter. Now set the source 10V to 0V.


5. Note down I2 by using ammeter. Now set the source 10V to 0V


7. By applying ΔE = I1ΔR using R.P.S find the current in ΔI.

PRECAUTIONS:





5. Avoid short circuit of RPS output terminals

S.

No

Name of the

apparatus Range Type Quantity

1 Regulated power

supply (0 – 30)V/2A digital 1No

2 Ammeter (0-20)mA MC 2No

3 Resistors Carbon

Composition -

4 Connecting Wires - - Required number

5 Experimental Board - - 1No



THEORETICAL CALCULATION: To find I1 :

To find I2 :

To find ∆I:-



Connection diagram To find I1 :

Tabular Column:

Connection diagram To find I2 :

Tabular Column

S.no Voltage (V) I1(mA)

1

S.no Voltage (V) I2(mA)

1



Connection diagram To find ∆I:-

Tabular Column :

S.no ∆E = I1.ΔR CHANGE IN CURRENT (∆I)

OBSERVATIONS :

RESULT:

Parameters I1(mA) I2(mA) ∆I

Theoritical

Practical



EXP. NO. DATE:

VERIFICATION OF RECIPROCITY& MILLIMANN’STHEOREMS

AIM:To verify Reciprocity theorem and Millimann’s theorem for the given circuit.

STATEMENTS:

Reciprocity theorem

In any linear bilateral, single source network, the ratio of excitation to the response is same even

though the positions of excitation and response are interchanged.

Millman’s theorem

It states that in a linear active network, if number of voltage sources V1,V2,……….Vn with internal

resistances R1,R2,……….Rn are connected in parallel, then this network can be replaced by a single

voltage source V1

in series with single resistance R1.

Where V1

= n21

nn2211

G GG

GVGVGV

R1

= n21 G GG

1

APPARATUS:


1 Dual channel regulated

power supply (0 – 30V) - 1No

2 Ammeter (0 – 10) mA MC 1No

3 Voltmeter (0-10)v MC 1No

4 Resistors Carbon

Composition

Each 1No





PROCEDURE:

Reciprocity theorem

1. Connect the circuit as per the fig (4.4).

2. Set the R.P.S output voltage to 10V and note down the response (I)

3. Disconnect the circuit and connect the circuit as per the fig (4.5).

4. Set the R.P.S output voltage to 10V and note down the response (Il)


Millimann’s theorem


2. Adjust the output voltage of sources to given values.

3. Note down the response current, I200Ω

4. Disconnect the circuit and connect the circuit as per the fig (2).

5. Adjust the output voltage of sources to given values. .

6. Find the voltage across open circuit terminals

7. Connect the circuit as shown in fig(3) and note down the values of voltmeter, ammeter to find the

value of resistance(R1)

PRECAUTIONS:





5. Avoid short circuit of RPS output terminals.



Millimann’s Theorem:

Theoretical calculations:

V1 =

n21

nn2211

G GG

GVGVGV

R1

= n21 G GG

1



CONNECTION DIAGRAMS :

To find I200Ω:

S.no V1 (V) V2 (V) I200Ω

1

To find VI:

S.No V1 (V) V2 (V) V1(V)

1



To find RI:

S.no V (V) I(A) R1 =V/I(Ω)

1



Reciprocity Theorem:


Before interchanging the positions of excitation and response:

After interchanging the positions of excitation and response:



Connection diagram before interchanging the positions of excitation and

response:

Fig (4.4)

Tabular Column:

S.

No

Appliedvoltage

(V1) Volt

Current

I(mA)

Connection diagram after interchanging the positions of excitation and

response:

Fig (4.5)

Tabular Column:

S.No Appliedvoltage

(V1) Volt

Current I1

(mA)



OBSERVATIONS:

Reciprocity Theorem:

Millimann’s Theorem:

RESULT:

S.No Ratio of response to the excitation Theoretical Value Practical Value

1 Before interchanging, V/I

2 After interchanging, V/Il

S.No Parameters Theoretical Value Practical Value

1 V1

2 R1

3 I200Ω



EXP. NO. DATE:

DETERMINATION OF SELF, MUTUAL INDUCTANCES AND

COEFFICIENT OF COUPLING

AIM :To determine the self-inductance, mutual inductance and coefficient of coupling of the given 1-

transformer.

APPARATUS:

S.

No Name of the apparatus Range Type Quantity

1 Single phase transformer 230V / 115V,

2KVA - 01No

2 1- auto transformer 230V / 0-

270V,10A, Induction 01No

3 Ammeter (0-2) A MI 01 No

4 Voltmeter (0-300) V MI 01No

5 Multimeter --- --- 01No


PROCEDURE:

To find resistance of coils:

By using multimeter measure the resistance of the coil 1,coil 2 and series connection of coil 1 & coil 2 and

find Rac1 ,Rac2 and Raceq by using given formulae Rac1=1.3 Rdc1 ,Rac2=1.3 Rdc2 and Raceq=1.3Rdceq

To find Z1:-

Apply rated voltage i.e 230 to primary winding and note down corresponding ammeter reading.

Then find out Z1 as shown in fig (1)

To find Z2:-

Apply rated voltage i.e 115 to secondary winding and note down corresponding ammeter reading.

Then find out Z2 as shown in fig(2)

To find Zeq:-

Apply voltage i.e 115 to the series connected windings and note down corresponding ammeter

reading. Then find out Zeq as shown in fig(3).



Circuit Diagram for self inductance (L1):

TABULAR COLUMN:

S.No V(Volts) I (amp)

1

Circuit Diagram for self inductance (L2):

TABULAR COLUMN:

S.No V(Volts) I(amp)

1



Circuit Diagram for Mutual Inductance(M):

TABULAR COLUMN:

S.No V(Volts) I(amp) Zeq=V/I

1

CALCULATIONS:

XL1 = =

XL2 = =

XLeq = =

XL1 = 2 fL1 L1 =

XL2 = 2 fL2 L2 =

XLeq = 2 fLeq Leq =

Leq = L1+L2-2M M=

Co-efficient of coupling K= =



PRECAUTIONS:

1. Ensure the minimum position of autotransformer during power on and off.




RESULT:



EXP. NO. DATE:

RESONANCE IN SERIES AND PARALLEL RLC CIRCUITS

AIM: To determine the resonant frequency fo, Bandwidth and quality factor Q, of the given series and

parallel RLC circuits.

APPARATUS:

S. no Name of the apparatus Range Type Quantity

1 (0 – 3)MHz Signal

generator

(0-20) VPeak to

Peak - 1No

2 Decade inductance Box (0-1.11H) - 1No

3 Resistors 100Ω,1k Carbon Composition 2No

4 Capacitors 0.1µF - 1No

5 Ammeter (0-10) mA MI 1No


7 Connecting wires - - Required Number

PROCEDURE:

Resonance in series and parallel RLC circuits:

1. Set the signal generator in sine wave mode and the output voltage to 20V peak to peak.

2. Connect the circuit as per fig (1.1) and vary the frequency of the input signal in steps and note down

the corresponding current through the circuit and tabulate the readings.

3. Reduce the frequency to zero and disconnect the circuit and plot the graph by relating dependent and

independent variables.

4. Connect the circuit as per fig (1.2) and repeat the steps 2 and 3.

5. From graph find the fo,f1&f2

PRECAUTIONS:

1. Keep the output voltage of the signal generator in zero volt position.






TABULAR COLUMN:

S.no

SERIES RESONANCE PARALLEL RESONANCE

Frequency, f

(Hz)

Current,

I(mA)

Frequency, f

(Hz)

Current,

I(mA)

Model Graphs:




SERIES RESONANCE

Resonant frequency, f0 = LC2π

1 =

Quality factor, Q = C

L

R

1

ωCR

1

R

ωL

Band width =fo/Q =.

PARALLEL RESONANCE



CONNECTION DIAGRAM FOR SERIES RESONANCE

Fig(1.1)

Resonant frequency, f0 =

Lower cut-off frequency, f1 =

Upper cut-off frequency, f2 =

Band width = f2 –f1 =

Quality factor, Q= 12

o

ff

f

=

CONNECTION DIAGRAM FOR PARALLEL RESONANCE :

Fig (1.2)

Resonant frequency, f0 =

Lower cut-off frequency, f1 =

Upper cut-off frequency, f2 =

Band width = f2 –f1 =

Quality factor, Q= 12

o

ff

f

=



OBSERVATIONS:

RESULT:

S.No Parameter

Series Resonant circuit Parallel Resonant circuit

Theoretical

Values

Practical

Values

Theoretical

Values

Practical

Values

1 Resonant Frequency, fo

2 Band width

3 Quality factor



EXP. NO. DATE: DETERMINATION OF Z AND Y PARAMETERS

AIM: To determine open circuit impedance parameters (Z) and short circuit admittance parameters(Y)

of the given two port network.

APPARATUS:


1 Regulated power supply (0 –

30)V - 1

2 Voltmeters (0-10)V MC 2

3 Ammeters (0-

10)mA MC 2

4 Resistors

5 Bread board - - 1


PROCEDURE:

1. Connect the circuit as per the fig (3.1) and set R.P.S. output voltage to 5 volts.

2. Note down the corresponding current (I1) through the input port and voltages (V2) across

the output port.

3. Disconnect the circuit and calculate Z11 and Z21 using the formulae, Z11=V1/I1 and Z21=V2/I1.


5. Note down the corresponding current (I2) through the output port and voltage (V1) across

the input port.

6. Disconnect the circuit and calculate Z22 and Z12 using the formulae, Z22=V2/I2 and Z12=V1/I2.


8. Note down the corresponding currents through the input and output ports I1 and I2.

9. Disconnect the circuit and calculate Y11 and Y21 using the formulae, Y11=I1/V1 and Y21=I2/V1.



12. Disconnect the circuit and calculate Y22 and Y12 using the formulae, Y22=I2/V2 and Y12=I1/V2.

PRECAUTIONS:





5. Do not short circuit the RPS output terminals .



Z Parameter Theoretical calculations:

Circuit Diagram To Find Z11&Z21:





Fig (3. 1)

S.no V1(volts) V2

(volts) I1(mA)

111

1

Vz

I (K) 2

21

1

Vz

I (K)


Fig (3. 2)

S.no V2(volts) I2 (volts) V1(mA) 2

22

2

Vz

I (K) 1

12

2

Vz

I (K)



Y PARAMETER THEORETICAL CALCULATIONS:

Circuit Diagram To Find Y11&Y21:



Fig (3. 3)

S.no V1(volts) I1(mA) I2(mA) 1

11

1

IY

V (mho) 2

21

1

IY

V (mho)




Fig (3. 4)

S.no V2(volts) I2

(volts) I1(volts)

222

2

IY

V (mho) 1

12

2

IY

V (mho)

OBSERVATIONS:

Z11

(K)

Z12

(K)

Z21

(K)

Z22

(K)

Y11

(mho)

Y12

(mho)

Y21

(mho)

Y22

(mho)

Theoretical values

Practical values

RESULT:



EXP. NO. DATE:

TRANSMISSION AND HYBRID PARAMETERS

AIM: To determine Transmission (ABCD) and Hybrid parameters of the given two port network.

APPARATUS:


1 Regulated power supply (0 –

30)V - 1

2 Voltmeters (0-10)V MC 2

3 Ammeters (0-

10)mA MC 2

4 Resistors Carbon

Composition -

5 Bread board - - 1


PROCEDURE:

Transmission Parameters:

1. Connect the circuit as per the given circuit diagram Fig(3.1) and set the RPS input voltage to 10V

2. Note down the corresponding current (I1) through the input port and voltages (V2) across the

output port.

3. Disconnect the circuit and calculate the parameter A and C using the formulae A=V1/V2 &

C=I1/V2

4. Connect the circuit as per the fig (3.2) .

5. Adjust the input voltage to 10V and Note down the corresponding currents (I1) & (I2) through the

input and output port.

6. Disconnect the circuit and calculate parameters B and D using the formulae, B= -V1/I2, D= -I1 /I2

7. Connect the circuit as per the fig (3.3) and set RPS input voltage to 10 volts.


9. Disconnect the circuit and calculate h11 and h21 using the formulae, h11= V1/ I1 and h21=I2/I1

10. Connect the circuit as per the fig (3.4) and set RPS output voltage to 10volts.

11. Note down the corresponding currents through output ports I1 and voltage at input port (V1).

12. Disconnect the circuit and calculate h22 and h12 using the formulae, h22=I2/V2 and h12=V1/V2

PRECAUTIONS:



3. Take the readings without parallax error.


5. Do not short circuit the RPS output terminals .



TRANSMISSION PARAMETERS THEORETICAL CALCULATIONS:

Circuit Diagram To Find B&D:

Circuit Diagram To Find A&C:



Circuit Diagram To Find A & C:

Fig(3.1)

S.no V1(volts) V2 (volts) I1(mA) A=V1/V2

C=I1/V2 (mhos)

Circuit Diagram To Find B & D:

Fig(3.2)

S.no V2(volts) I2 (volts) V1(mA) B= -V1/I2 Ω D= -I1/I2



Hybrid Parameter Theoretical calculations:

Circuit Diagram To Find h11 & h21:




y Circuit Diagram To Find h11 & h21:

Fig(3.3)

S.no V1(volts) I1(mA) I2(mA) h11=V1/I1 Ω

h21=I2/I1


Fig(3.4)

S.no V2(volts) V1(volts) I2(mA) h12= V1/V2 h22=I2/V2(mho)

OBSERVATIONS:

Parameters

A

B () C(mhos) D h11(Ω)

h12

h21

h22(mhos)

Theoretical

values

Practical values

RESULT:



EXP. NO. DATE:

MEASUREMENT OF 3-PHASE POWER BY

USING TWO WATTMETER METHOD

Aim: To measure the three-phase power by two wattmeter method.

Apparatus:

S.No Apparatus Range Type Qty

1 Voltmeter (0-600V) M I 1

2 Wattmeter 1, 600V, 10A, UPF Dynamometer 2

3 Ammeter 0-10A, M I 3

4 Resistive load/ Lamp

load - 3-Ø 1

Procedure :

1. Connect the circuit as per the circuit diagram.

2. Switch on the supply.

3. Increase the load step by step until the ammeter reaches the rated current.

4. Note down the readings.

5. Reduce the load to minimum position and switch off the supply.



CIRCUIT DIAGRAM:

TABULAR COLUMN:

Voltage

(V)

Current(A) Wattmeter (W) Measured

Values

Output

powerW=

WR+

WY+WB

IR IY IB W1 W2 W=W1+W2 WR WY WB



CALCULATIONS:

PRECAUTIONS:



3. Initially keep the load in minimum position.

RESULT:



EXP. NO. DATE:

DETERMINATION OF PARAMETERS OF CHOKE COIL Aim: To find the parameters of choke coil i.e., Resistance, Inductance and hence finding the Power

factor and Quality factor of the given choke coil.

Apparatus:

S.No Apparatus Range Type Qty

1

Voltmeter

(0-300)V

(0-150)V

(0-30)V

M I

MC

MC

1

1

1

2 Variac 230V/(0-270)V 1Ф 1

3 Ammeter (0-10)A,

(0-10)A

M I

MC

4 RPS (0-30)V DC 1

5 Rheostat WW 1

Procedure to find Impedance(Z):

1. Select a fuse wire in such a way that the fuse rating should be less than the maximum current that

is drawn by the circuit.

2. Connections are made as per the circuit diagram.

3. Suitable AC supply is taken by keeping the variac in minimum output position.

4. The single phase variac is varied to regulate the voltage to the circuit.

5. The readings are taken by varying the variac in such a way that the current through and voltage

across the choke coil should not exceed the rating of it.

6. After getting 4 or 5 readings supply is OFF.

Procedure to find Resistance(R):

1. Select a fuse wire in such a way that the fuse rating should be less than the maximum current that

is drawn by the circuit.

2. Connections are made as per the circuit diagram.

3. Suitable DC supply is given to the circuit.

4. The variable load is varied in steps to regulate the current in the circuit.

5. The readings are taken by varying the variable load in such a way that the current through the

choke coil should not exceed the rating of it.

6. After getting 4 or 5 readings supply is OFF.



CIRCUIT DIAGRAM TO FIND “R”:

FOR “R”

S.No V(Volts) I (amp) R=V/I Ω



CIRCUIT DIAGRAM TO FIND “Z”:

FOR “Z”:

S.No V(Volts) I (amp)



CALCULATIONS:

The values of R, Z are obtained from above tabular forms

Power factor= R/Z

Quality factor= X/R

PRECAUTIONS:



3. Initially keep the load in Maximum position.

RESULT:







Documents

Department of Electrical and Electronics Engineering CIRCUITS LAB.pdfMaximun Power Transfer theorem It states that, maximum power will be transferred from source to load when the load