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ELECTRICAL TECHNOLOGY-LAB

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

II/IV B.TECH II-SEM

SUB: ELECTRICAL TECHNOLOGY LAB

LAQSHYA INSTITUTE OF TECHNOLOGY AND SCIENCES


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LAQSHYA INSTITUTE OF TECHNOLOGY AND SCIENCES

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

ELECTRICAL TECHNOLOGY LAB

R13 REGULATION II YEAR B.TECH ECE II SEM

LIST OF EXPERIMENTS:

1. VERIFICATION OF KVL AND KCL

2. SREIES AND PARALLEL RESONANCE

3. TIME RESPONSE OF FIRST ORDER RC-RL NETWORK FOR PERIODIC NON SINUSOIDAL

INPUTS

4. TWO PORT NETWORK PARAMETERS Z-Y PARAMETERS CHAIN MATRIX AND

ANLYTICAL VERIFICATION

5. TWO PORT NETWORK PARAMETERS ABCD AND H- PARAMETERS

6. VERIFICATION OF SUPER POSOTION AND RECIPROCITY THEOREMS

7. VERIFICATION OF MAXIMUM POWER TRANSFER THEOREMS

8. VERIFICATION OF THEVINENS AND NORTONS THEOREMS

9.MAGNETIZATION CHARACTERISTICS OF DC SHUNT GENERATER

10. SWINBURNE’S TEST ON DC SHUNT MACHINE

11. BRAKE TEST ON DC SHUNT MOTOR

12.OC & SC TEST ON SINGLE PHASE TRANSFORMER

13.LOAD TEST ON SINGLE PHASE TRANSFORMER


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VERIFICATION OF THEVENIN’S, NORTON’S THEOREMS

AIM:

To study and verify the Thevenin’s, Norton’s and maximum power transfer theorems

theoretically and practically

APPARATUS:

S.NO APPARATUS NAME RANGE QUANTITY

01 Regulated Power supply (0-30)V 01

02 Resistors 1KΩ 02

03 Resistors 560Ω 01

04 Resistors 2.2KΩ 03

05 Resistors 100Ω 02

06 Decade Resistance Box ---- 0107 DC ammeters (0-20)mA 01

08 DC voltmeter (0-30)V 01

09 Bread Board --------- 01

10 Connecting wires -------- AS Required

CIRCUIT DIAGRAM:

THEVENIN’S & NORTON’S CIRCUIT:

Thevenin’s & Norton’s Circuit

PROCEDURE:

(a) THEVENIN’S THEOREM:

1. Connect the circuit as per the circuit diagram

2. To find Thevenin’s voltage Vth, remove the load resistor RL, and find the voltage across the load

terminals by applying source voltage


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3. To find Thevenin’s Resistance Rth, remove the load resistor RL , and find the resistance across

the load terminals by short circuiting the voltage source

4. Now construct the Thevenin’s equivalent circuit and find the load current, by connect ing load

to its terminals

5. Compare the theoretical and practical values

(b) NORTON’S THEOREM:


2. To find Norton’s current IN, short circuit the load terminals, and find the current in the load

terminals by applying source voltage

3. To find Norton’s Resistance RN, remove the load resistor RL , and find the resistance across the

load terminals by short circuiting the voltage source

4. Now construct the Norton’s equivalent circuit and find the load current, by connecting load to

its terminals

5. Compare the theoretical and practical values

TABULAR COLUMN:

(a) THEVENIN’S THEOREM: (b) NORTON’S THEOREM:

PRECAUTIONS:

1. Avoid loose and wrong connections

2. Handle the equipments carefully.

RESULT: Thevenin’s, Norton’s theorems are studied and verified theoretically and practically.

s.no IN (mA) RN (Ω) IL (mA)

Theor Pract

s.no Vth (V) Rth (Ω) IL (mA)

Theor Pract


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VERIFICATION OF SUPERPOSITION THEOREM

AIM:

To study and verify the superposition theorem theoretically and practically

APPARATUS:

S.NO apparatus Range Quantity

1

2

3

4

5

Regulated power supply

Resistors

Dc ammeters

Bread board

Connecting wires

(0-30)v

1KΩ,560Ω,2.2KΩ

(0-20) mA

---------------

--------------

2

1,1,1

1

1

As required

CIRCUIT DIAGRAM:


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PROCEDURE:


2. Take the reading of ammeter which gives the current through the 1kΩ resistor by applying two

voltage sources v1 and v2 and assumed it as I.

3. Now apply the only V1 and take the reading of ammeter and assumed it as I1 and v2 must be

shorted.

4. Now apply the only V2 and take the reading of ammeter and assumed it as I11

and v1 must be

shorted.

5. If I= I1+I11

then superposition theorem is verified.

TABULAR COLUMN:

S.NO Voltage(V1) Voltage(V2) Current(I1) Current(I

11) Current(I) I =I

1+I

11

I1= Current when voltage source V1 acting

I11

= Current when voltage source V2 acting

I = Current when voltage sources V1,V2 acting

PRECAUTIONS:

1. Avoid loose and wrong connections

2. Handle the equipments carefully.

RESULT:

The superposition theorem is studied and verified theoretically and practically.


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VERIFICATION OF RECIPROCITY

RECIPROCITY THEOREM:

AIM:

To study and verify the Reciprocity and Milliman’s theorem theoretically and practically

APPARATUS:

S.NO APPARATUS NAME RANGE QUANTITY

01 Regulated power supply (0-30)V 01

02 Resistors 1KΩ 5

03 Dc ammeter (0-20)mA 1

04 Bread board -------- 1

05 Connecting wires -------- As required

CIRCUIT DIAGRAM:

PROCEDURE:


2. Case(i): Apply the voltage across AA’ and note down the readings of ammeter at BB’ and and

measure the transfer resistance .

3. Case(i): Apply the voltage across BB’ and note down the readings of ammeter at AA’ and and

measure the transfer resistance .

4. If the transfer resistance is same in both cases then reciprocity theorem is proved.


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STUDY OF SERIES AND PARALLEL RESONANCE CIRCUITS

AIM:

To study and verify the series and parallel resonance circuits theoretically and practically.

APPARATUS:

S.NO NAME RANGE QUANTITY

1 Function generator ------ 2

2 Decade resistance box ------ 1

3 Decade inductance box ------ 1

4 Decade capacitance box ------ 1

5 Connecting wires ------ As required

6 Bread board ------ 1

7 Ac millimeter ------ 1

CIRCUIT DIAGRAM:

Series resonance circuit Parallel resonance circuit

Procedure:

series resonance:

1. Connect the circuit as per the circuit diagram by fixing the values of resistance,

inductance and Capacitance by varying corresponding decade box to desired levels.

2. First you notice that the current is maximum at lower frequencies.

3. By varying the frequency note down the corresponding current by measuring the peak

values.

4. At a frequency known as Fo resonance and so the current is max at the point.

5. On favorite further increase the current again decreases.


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Parallel resonance:

1. Connect the circuit as per the circuit diagram by fixing the values of resistance,

inductance and Capacitance by varying corresponding decade box to desired levels.

2. First notice that the current is maximum at lower frequencies.

3. By varying the frequency note down the corresponding current by measuring the peak

values.

4. At a frequency known as Fo resonance occurs and so the current is max at the point.

5. On further increase the current again decreases.

TABULAR COLUMN:

series resonance: Parallel resonance:

S.NO FREQUENCY CURRENT S.NO FREQUENCY CURRENT

Ther Pract Ther Pract Ther pract Ther Pract

1 1

2 2

3 3

4 4

5 5

Model graphs:

series resonance: Parallel resonance:

PRECAUTIONS:

1. Avoid loose and wrong connections and handle the equipments carefully.

RESULT:

The series and parallel resonance circuits are studied and verified theoretically and

practically.


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Z AND Y PARAMETER

AIM:

To find out the Z and Y parameters theoretically and practically.

APPARATUS:


1 Regulated power

supply

(0-30)V 2

2 Resistors 560Ω,1KΩ,2.2KΩ 1


4 Dc voltmeter (0-30)V 1



CIRCUIT DIAGRAM:

Procedure To find Z-Parameters

1. Connect the circuit as shown in fig.

2. Open circuit port-2 (i.e. I2 = 0 ) and measure V1,I1 and V2 and calculate Z11 & Z21 using the

formulae

02

1

1

11

I

I

V Z 0

2

1

2

21 I

I

V Z

3. To Measure Z12 and Z22, open circuit port-1 (i.e. I1=0) and measure V1, V2 and I2 and

calculate Z12 & Z21 using the formulae

012

112 I

I

V Z 0

1

2

2

22 I

I

V Z


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To find Y-Parameters

1. Connect the circuit as shown in fig.

2. Short circuit port-2 (i.e. V2 = 0 ) and measure V1, I1 & I2 and

Calculate Y11 & Y21 using the formulae

02

1

1

11 V V

I Y 02

1

221 V

V

I Y

3. To Measure Y12 and Y22, short circuit port-1 (i.e. V1=0) and measure V2, I1 and I2 and

calculate Y12 & Y22 using the formulae

01

2

1

12 V

V

I Y 01

2

222 V

V

I Y

TABULAR COLUMN: For Z Parameter

S.NO V1(volts) V2(volts) I1(mA) I2(mA) Z11(ohms) Z12(ohms) Z21(ohms) Z22(ohms)

Ther Pract Ther Pract Ther Pract Thr pra

1

2

For Y Parameter

S.NO V1(volts) V2(volts) I1(mA) I2(mA) Y11(ohms) Y12(ohms) Y21(ohms) Y22(ohms)

Ther Pract Ther Pract Ther Pract Thr pract

1

2

PRECAUTIONS:

1. Avoid loose and wrong connections and handle the equipments carefully.

RESULT: The Z and Y parameters for given circuit are calculated theoretically and practically.


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TRANSMISSION AND HYBRID PARAMETER

AIM:

To find out the transmission and hybrid parameters theoretically and practically.

APPARATUS:


1 Regulated power

supply

(0-30)V 2

2 Resistors 560Ω,1KΩ,2.2KΩ 1


4 Dc voltmeter (0-30)V 1



CIRCUIT DIAGRAM:

Procedure For transmission parameter

1) All the connections are made as per the ckt diagram.

2) First the o/p port is open ckted (I2= O) and a voltage V1= 5V is applied to the I/p port.

3) Now the current I1 and the voltage V2 across the open ckted O/P port are noted down.

4) Then A= V1 / V2 when I2=0 and C=I1/V2 when I2=0 are calculated.

5) Now the O/P port is short ckted V2=5v applied to the I/P port.6) Then the current I1 and I2 are noted down. Then the parameters B=V1 /-I2 (V2=0) and D = I1/I2

(V2 = 0) are calculated.

7) The practical values are verified with the theoretical values.


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For hybrid parameter

1) All the connections are made as per the circuit diagram.

2) First the output port is short circuited (V2=0) and a voltage V1=5V is applied to the input port.

3) The current I1&I2 are noted down.

4) Then the parameters h11=V1/ I1 when V2=0, h22 = I2/I1 when V2 =0 are calculated.5) Now the input port is open circuited (I1=0) and voltage V2 =5v is applied to input port

6) Then the voltage V1 and current I2 are noted down. Then the parameters h12 = V1/V2 when I1=0,

h22 =I2/V2when I1=0 are calculated.

7) The practical are verified with the theoretical values.

TABULAR COLUMN: for transmission parameter

S.NO V1(VOLTS) I1(mA) V2(volts) I2(mA) A B C D

thr pra thr pra thr pra thr pra

1

2

for hybrid parameter

S.NO V1(VOLTS) I1(mA) V2(volts) I2(mA) H11=V1/I1 H12=V1/V2 H22=I2/V2 H21=I2/I1

thr pra thr pra thr pra thr pra

1

2

RESULT:

The Transmission and hybrid parameters for given circuit are calculated theoretically and

practically.


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Critical speed: Speed for which the given shunt field resistance becomes critical field resistance.

Critical field resistance: The value of field resistance at which D.C. generator will fail to excite.

CIRCUIT DIAGRAM:

PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Keep the motor rheostat in minimum position and generator rheostat in maximum position.

3. Switch on the supply and start the motor with the help of the starter.

4. Adjust the speed of the motor-generator set to the rated speed by controlling the motor field

rheostat the speed is to be maintained constant throughout the experiment.

5. Note down the voltmeter reading at zero field current, increase field current in steps by

changing the generator field rheostat simultaneously note down the field current (I f ) and

terminal voltage (E) across the generator armature terminals.

6. Continue till saturation of the field is reached.


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TABULAR COLUMN:

S. No Field current (Ir ) (Amps) Generated arm voltage (E0) (Volts)

MODEL GRAPHS:

E0 (Vs) Ir

E0

IF

PRECAUTION:

1. Perform the experiment at constant speed.

2. Readings are to be taken for uniformly increasing field current.

3. Check must be made for residual magnetism, The field terminals may be required to be

reversed.

RESULT:

Hence the magnetization characteristics or open circuit characteristics of DC shunt generator are

performed and its critical speed and critical resistance are determined.

Critical speed = ----------- R.P.M

Critical resistance = --------- Ω


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BRAKE TEST ON DC SHUNT MOTOR

AIM: To determine the performance characteristics of DC shunt motor by conducting brake test

APPARATUS REQUIRED:

S.NO APPARATUS RANGE TYPE QUANTITY

01 Ammeter 0-20A MC 01

02 Voltmeter 0-300V MC 0103 Rheostat 300Ω/1.5A Wire wounded 01

04 Tachometer ---- Digital/Analog 01

05 Connecting wires ----- ----- Required

NAME PLATE DETAILS:

SPECIFICATIONS MOTOR

Power rating 3HP

Voltage 220V

Field Current 0.6A

Speed 1500rpm

Armature Current 12 Amperes

Type Shunt

THEORY:

In this method the motor is subjected to direct mechanical loading by attaching a brake drum and water

cooled pulley to the motor shaft. A rope or belt is wound the pulley at it’ two ends. The two ends are

connected to two spring balances S1 and S2 The tension of the belt can be adjusted by tightening it on

the pulley. The tangential force on the pulley is equal to the difference of the two spring balance

readings.

Tsh = (S1 ~ S2)* 9.81* R N-m, Where ‘R’ is the radius of the pulley in meters and S1 and S2

are the spring balance readings in Kg.

Power output = (2∏N/60) × (S1 ~ S2) × 9.81× R Watts (N-m/sec), Where N is the speed.

Power input = VI watts, Where V is the motor input voltage and I is the motor input current.

% Efficiency = (output / input) × 100


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CIRCUIT DIAGRAM:

PROCEDURE:

1. Connect the circuit as per the circuit diagram.

2. Keep the field rheostat at minimum resistance position.

3. Check that the rope on the pulley is free so that there is no load on the pulley.4. Start the motor slowly using the starter.

5. Adjust the field current so that the motor runs at rated speed.

6. Apply the load on the pulley gradually in steps by tightening the rope around it.

7. Take the readings of the ammeter, voltmeter, spring balance and speed at every step.

8. Cool the pulley throughout the experiment by pouring the water.

9. Continue the experiment till full load current of the motor is reached.

10. Tabulate the observations.

TABULAR COLUMN:

s.no S1(kg) S2(kg) V(volts) I(amps) N(rpm) Input Output Torque O/P(BHP) %η

1


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CALCULATIONS:

Radius of the drum(R) =……0.152cm………….

The torque (Tsh) = (S1 - S2) ×9.81× R N-m

Power output = (2∏NT/60) Watts

B.H.P =Output /735.5

MODEL GRAPHS:

ŋ N ŋ

O/P T BHP

PRECAUTIONS:

(1) Cool the pulley when the experiment is performed.

(2) While measuring the radius of the pulley effective radius must be considered.

RESULT:

The performance characteristics of DC shunt motor were determined by conducting brake test


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OPEN CIRCUIT AND SHORT CIRCUIT TEST OF A SINGLE PHASETRANSFORMER

AIM:

To draw the equivalent circuit of a single phase transformer by conducting open circuit test andshort circuit test also determining the losses.

APPARATUS REQUIRED:

S.NO APPARATUS RANGE TYPE QUANTITY

01 1-ø variac 230V/(0-270V) AE 01

02 Voltmeter (0-300)V MI 0103 Voltmeter (0-75)V MI 01

04 Ammeter (0-2.5)A MI 01

05 Ammeter (0-5)A MI 01

06 Wattmeter 300V/5A LPF 01

07 Wattmeter 150V/5A UPF 0108 1-ø Transformer 230V/230V, 1KVA ------- 01

09 Connecting wires ------ ----- RequiredTHEORY:

Open circuit test: This test is performed to determine the core or iron losses, and also helpful indetermining the magnetizing component Im, working component or energizing component Iw. In this testsecondary (usually high voltage) winding is left open, all metering instruments are connected onprimary side and normal rated voltage is applied to the primary (low voltage) winding.

Short circuit test: This test is also known as impedance test. It is performed to determine the fullload copper loss and equivalent resistance and reactance referred to secondary side. In this test, theterminals of the secondary (usually low voltage) winding are short circuited; all meters are connected

on primary side and a low voltage, usually 5 to 10% of normal rated primary voltage at normalfrequency is applied to the primary.

PROCEDURE:

Open circuit test:

1. Make the connections as per the circuit diagram

2. Now apply the rated voltage to the low voltage side of the transformer

3. Note down the readings of the ammeter, voltmeter, and wattmeter and perform the calculations.

Short circuit test:

1. Make the connections as per the circuit diagram.

2. Now apply the rated current to the high voltage side of the transformer.

3. Note down the readings of the ammeter, voltmeter and wattmeter and perform the calculations.


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CIRCUIT DIAGRAM:

Open circuit test:

Short circuit test:

Equivalent Circuit:


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TABULAR COLUMN:

Open circuit test: Short circuit test:

V0(volts)

Io (Amps)

W0 (Watts)

FORMULAE:

Open circuit test: Short circuit test:

V0 Io COSфo = W Zsc=Zo1=Vsc / Isc

COSфo = W / V0 Io (Isc)2 Ro1=WSC

Iw = Io COSфo Ro1=Wsc / (Isc)2

Iµ =Io SINфo X01 = (ZSC2 – R012)½

Xo = V0 / Iµ = V0/ Io SINфo

Ro = V0/ Iw = V0/ COSфo

I0 = (Iµ2 + Iw

2)½

PRECAUTIONS:

1. Avoid loose connections2. The applied current in the short circuit test should not exceed the rated value.

3. Keep the meters and variac in minimum position at the time of starting as well as the end of the

experiment.

4. Note the readings without any error.

RESULT:

The equivalent circuit of a single phase transformer referred to primary side, no load losses and full

load copper losses are determined by conducting open circuit and short circuit test

VSC(volts)

ISC (Amps)

WSC (Watts)


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Constant –Losses Wc=input –arm cu losses, Wc =VIo-Ia2 Ra , Now the machines efficiency at any other

load can determined by Wc, Let I be the load current at which efficiency required. Then armature

current Ia =I- Ish (motor) , Ia =I+ Ish (generator)

CIRCUIT DIAGRAM: (SWINBURNE’S TEST)

PROCEDURE (SWINBURNE’S TEST):

1. Make the connections as per the circuit diagram.

2. Start the DC motor with starter.

3. Take the no-load readings, at rated speed.

4. Measure the armature and field resistance using given circuit.

MODEL CALCULATIONS:

When the machine is running as a motor

Input power =VI,

Armature cu. Losses + Ia2 Ra

Constant losses =Wc

Total loss =Wc+ la2 Ra

Output =Input –losses

Efficiency = Output /input


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When the machine running as a Generator

Output power =VI

Armature cu. Losses =Ia2Ra

Constant losses =Wc

Total loss =Wc + Ia2 Ras

Input power = Output power + losses

Efficiency = output/ input

TABULAR COLUMN:

Swinburne’s test:

S.No volts armaturecurrent(amps)

fieldcurrent(amps)

For motor:

s.no V(volts)

Ic

(amps)

Ia

(amps)

Input(watts)

Losses(watts)

Output(watts)

% Efficiency(%η)

For generator:

s.no V(volts)

Ic

(amps)

Ia

(amps)

Input(watts)

Losses(watts)

Output(watts)

% Efficiency(%η)

PRECAUTIONS:

1. Experiment is performed at no-load only.

2. Keep the field rheostat at minimum position and armature rheostat at maximum position

3. Initially RF in minimum position.4. Belt around the brake drum is loosening for no load.

5. In field control speed shouldn’t be exceeded beyond 1800 rpm.

RESULT:

The efficiency of DC shunt motor is determined at full load, half load one-quarter load by conducting

Swinburne’s test and the speed characteristics of DC shunt motor are determined by performing speed

control methods.


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CIRCUIT DIAGRAM:

PROCEDURE:

1. Connections made as per circuit diagram.

2. At some constant voltage by varying the load resistance note down the readings of Ammeter.

3. Calculate the power delivered to the load.

4. Calculate and find out the resistance at which value maximum power is transmitted to the load.

5. Calculate the internal resistance of the circuit theoretically and verify with the practical value.

6. Draw graph between the power and load resistance.

TABULAR FORM:

S.NO Voltage (V) Current (A) RL=V/I (Ω) P=I2R(Watt)


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MODEL GRAPH:

RESULT:


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KVL AND KCL

AIM: TO VERIFY KCL AND KVL.

APPARATUS: DC NETWORK KIT AND CONNECTING WIRES.

THEORY: KCL AND KVL are used to solve the electrical network, which are not solved by the

simple electrical formula.

KCL: It states that in any electrical network the algebric sum of currents meeting at a point

is zero. Consider the case of few conductors meeting at a point A in the fig. Assuming incoming

currents

to be positive and the outgoing currents to be negative.

I1+(-I2)+(-I3)+I4+(-I5)=0

Incoming current=outgoing current

KVL: It states that the algebric sum of product of current and resistance in each of the

conductors in any closed path in a network plus the algebric sum of the e.m.f. in the closed path

is zero.

ΣIR+ΣE.M.F.=0

CIRCUIT DIAGRAM:


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PROCEDURE

KCL:

1. Make the connection according to the ckt diagram 2. Set the three rheostats to their max value.

3. Switch on the power supply

4. Change the setting of the rheostats to get different readings in all the three

ammeters.

5. Measure the current in the three ammeters

6. Check that at every time current in the main branch is equal to the sum of

currents in the two branches. repeat the setting of the rheostat

7. Switch off the power supply.

KVL:

1. Connect the circuit as per the circuit diagram 2. Switch on the power supply

3. Note down the readings of the voltmeters

4. Change the value of the rheostat and repeat the step several times andswitch off the power supply.

OBSERVATION TABLE:

KCL:

SR.NO. APPLIED VOLTAGE

volts

I1 (mA)

I2 (mA)

I (mA)

I =I1+I2 (mA)

REMARK

KVL:

SR.NO. APPLIED VOLTAGE

volts

V1 (volts)

V2 (volts)

V3 (volts)

RESULT

Vl=V1+V2+V3

(volts)

REMARK

RESULT:

1 The incoming current is found to be equal to the outgoing current

2 The total input voltage is equal to the total voltage drop in the ckt.


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LOAD TEST ON SINGLE PHASE TRANSFORMER

AIM:

To determine the efficiency

To find the variation of secondary terminal voltage with respect to the load

current.

APPARATUS REQUIRED:

S.No. Item Type Range Quantity

1 Auto Transformer 230/(0-270) V, 1φ - 1

2 Wattmeter300 V, 5A UPF 1

150 V, 5 A UPF 1

3 Ammeter(0-10) A MI 1

(0-5) A MI 1

(0-300) V MI 1

4 Voltmeter (0-150) V MI 1

5 Connecting Wires 2.5sq.mm Copper Few

6 Load (5 KW,230V) - 1

PRECAUTION:

1.The Variac should be kept in minimum position while switching on and switching off the

supply side DPSTS.

2. At the time of switching on the supply there should not be any load connected.


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RANGE FIXING:

Rated primary current, I 1 =

Rated secondary current, I 2 = Rated capacity in VA Secondary voltage, V 2

The load used is resistive in nature.

The range of A p, V p, W p are …………A, ……………V, …………W respectively.

The range of As, Vs, Ws are ……………A, …………….V, …………..W respectively.

PROCEDURE:

1. Excite the transformer to its rated voltage on no load.

2. Observe the meter readings at no load.

3. Gradually load the transformer and note the meter readings for each loading.

4. Load the transformer to its rated capacity i.e. till it draws rated current from the

supply.

Note that applied voltage to the primary side should be kept at its rated voltage on

loading.

FORMULA USED:

Output power = WS

Input Power = WP

% efficiency =W

S 100

W P

% Regulation = Vso -Vs 100 (where VS0 – no load secondary rated terminal voltage) so

4


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CIRCUIT DIAGRAM:

TBULAR COLUMN:

Sl. VP IP WP (Watts) VS IS WS (Watts) % % No.

Volts Amps Volts Amps Efficie Regula

Observed Actual Observed Actual tion ncy

MODEL GRAPHS:

RESULT: Thus the efficiency and regulation of a three phase transformer were calculated.


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Time response of Series RL and RC circuits

Aim: To draw the time response of first order series RL and RC network for periodic

Non-Sinusoidal function and verify the time constant.

Apparatus:

Theoretical Calculations:

1

Function generator 1

2

Decade Resistance box 1

3

Decade Inductance box 1

4

DecadeCapacitance box 1

5

CRO 1

6

CRO probes 1

7

Connecting wires As required


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Circuit diagrams: Series RL Circuit

Series RC Circuit


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MODEL GRAPH:

Procedure:

Series RL Circuit:

1. Connections are made as shown in the fig-1.

2. Input voltage (Square wave) is set to a particular value.

3. The waveform of voltage across inductor is observed on CRO and the waveform

is drawn on a graph sheet.

4. The time constant is found from the graph and verified with the theoretical

value. Series RC Circuit:

1. Connections are made as shown in the fig-2.

2. Input voltage (Square wave) is set to a particular value.

3. The waveform of voltage across the capacitor is observed on CRO and

the waveform is drawn on a graph sheet.

4. The time constant is found from the graph and verified with the theoretical value.

Result :

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