# Edc Lab Manuals[1]

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Ex. no: 1 Date:

VERIFICATION OF KVL

AND KCL

AIMTo Verify Kirchhoffs voltage and current laws for a given circuit.

APPARATUS REQUIRED

S.No. 1 2 3 4 5 6

Description Regulated Power Supply Resistor Ammeter Voltmeter Bread Board Connecting wires

Type Variable Carbon Moving Coil Moving Coil

Range (0-30)V 560 (0-30)mA (0-10)mV

Quantity 1 3 3 3 1

THEORY: OHMS LawIn electrical circuits, Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them The mathematical equation that describes this relationship

Where V is the potential difference measured across the resistance in units of volts; I is the current through the resistance in units of amperes and R is the resistance of the conductor in units of ohms.

Kirchhoffs Current lawAt any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node.

The current entering any junction is equal to the current leaving that junction. i1 + i4 = i2 + i3

Kirchhoffs Voltage LawThe directed sum of the electrical potential differences a round any closed circuit must be zero The sum of all the voltages around the loop is equal to zero. v1 + v2 + v3 + v4 = 0

PROCEDURE Ohms Law1. Connections are made as per the circuit diagram 2. Using the RPS, Source voltage is set 3. Connect the ammeter in series with the resistors and measure the deflection of current. Measure the value of I1,I2,I3

4. Compare the measured value of current to the theoretical value. The Ohms law is verified by v = IR. The combined resistance measured from terminals A and B is given by Rab =r1+r2. Resistors in parallel is measured across terminals A and B is given by I/Rab = I/R1+I/R2. Equivalently Rab = R1.R2/(R1+R2) 5. The above procedure is repeated by varying source voltage in steps at 5V to 30V

KIRCHOFFS CURRENT LAW1. Connections are made as per the circuit diagram 2. Using the regulated power Supply, Source voltage is set to 5V 3. Deflections are shown in all the three ammeters 4. Observe the readings of ammeter in each branch 5. The kirchoffs current law is verified by I total = I1+I2 6. The above procedure is repeated by varying source voltage in steps at 5v to 30V

Kirchoffs Voltage Law1. Connections are made as per the circuit diagram 2. Using the regulated power Supply, Source voltage is set to 5V 3. Readings shown in all the three voltmeters are tabulated 4. Kirchhoffs Voltage law is verified by V= V1+v2 5. Measure the voltage across the each branch and tabulate the reading 6. The above procedure is repeated by varying source voltage in steps at 5V to 30V

RESULT:Thus KVL and KCL are verified theoretically and practically

CIRCUIT DIAGRAM KIRCHOFFS CURRENT LAW(0-1 0)mA (0-1 0)mA

+

A

560 ohm R 1 s

+ 5 60 o hms R 3

A

560 ohm R 2 s

(0-30)V 1 +

A

I2

KIRCHOFFS VOLTAGE LAW

+

V

+

V

+

5 0o m R1 6 hs

5 0o m R2 6 hs

(0 0 1 -3 )V

TABULATION KCL

S.No

Input Itotal voltage V mA

I1 mA

I2 mA

I1+I2 mA

Theoretical I1 value mA mA

(0-10 0V

(0-10 )V

(0-10 )V

V

5 0o m R3 6 hs

I2 mA

I1+I2 mA

KVL

S.No

Input V1 voltage V V

V2 V

V3 V

V1+V2+V3 Theoretical V1 value V V V

V2 V

V3 V

V V

Ex.no:2 VERIFICATION OF THEVENIN AND NORTON THEOREMSDATE:

AIM

To Verify Thevenin theorem and Norton theorem practically for given circuit

APPARATUS REQUIRED

S.No. 1 2 3 4 5 6 7 8

Description Regulated Power Supply Resistor Ammeter Voltmeter Decade resistance box Bread Board Connecting wires Multimeter

Type Variable Carbon Moving Coil Moving Coil

Range (0-30)V 560,680,1k (0-10)mA (0-30)mV

Quantity 1 1,2,1 1 1 1 1

THEORY THEVENIN'S THEOREMAny combination of batteries and resistances with two terminals can be replaced by a single voltage source e and a single series resistor r. The value of e is the open circuit voltage at the terminals, and the value of r is e divided by the current with the terminals short circuited.

Thvenin's theorem states that at a pair of terminals a network composed of lumped, linear circuit elements may, for purposes of analysis of external circuit or terminal behavior, be replaced by a voltage source V(s) in series with a single impedance Z(s).

Norton's TheoremAny collection of batteries and resistances with two terminals is electrically equivalent to an ideal current source i in parallel with a single resistor r. The value of r is the same as that in the Thevenin equivalent and the current i can be found by dividing the open circuit voltage by r.

Norton's theorem for linear electrical networks, states that any collection of voltage sources, current sources, and resistors with two terminals is electrically equivalent to an ideal current source, I, in parallel with a single resistor, R.

PROCEDURE

1. Connections are made as per circuit diagram 2. Vary RPS and set input voltage of 1V 3. Note down voltmeter and ammeter reading 4. Switch off supply and make the connection 5. Measure Rth. Rth= Thevenin and Norton resistance 6. Set an input voltage 10V in RPS and note down voltmeter reading

7. Switch off supply and make connection 4 8. Set an input voltage 10V in RPS and note down voltmeter reading 9. Draw the Thevenin equivalent circuit and Norton equivalent circuit 10. Calculate the IL value using the formula 11. IL = Vth/(Rth+Rl) 12. Il = In*Rn/(Rn+Rl)

RESULTThus Thevenin and Nortons theorem are verified practically and theoretically Theoretical Value = -----------Practical Value =_______

TO MEASURE IL

680 ohms R 1 560 ohms R 2

(0-30)V 1

V

(0-30)V

680 ohms R 3

+ (0-10)mA

A

TO MEASURE VTH680 ohms R 1 560 ohms R 2

(0-30)V 1

V

680 ohms R 3

+ (0-30)V

+

V

(0-30)V

TO MEASURE RTH

R4 1k

+

680 ohms R 1

560 ohms R 2

680 ohms R 3

+

Multimeter 1

680 ohms R 1

560 ohms R 2

680 ohms R 3

(0-30)V 1

(0-10)mA +

A

THEVENIN EQUIVALENT CIRCUIT

900 ohm R 1 s th

5V 1

NORTON EQUIVALENT CIRCUIT

A

TABULAR COLUMN TO MEASURE IL

V1(V) IL(Ma)

900 ohms R 1

1K RL 1

2.5mA +

1K RL 1

TO MEASURE Rth TO MEASURE Vth or Voc TO MEASURE IN or Isc

V1(V) IL(Ma)

V1(V) IL(Ma)

Ex.no:3DATE:

VERIFICATION OF SUPERPOSITION THEOREM

AIM:To Verify Superposition theorem for a given circuit

APPARATUS REQUIRED:

S.No. 1 2 3 4 5

Description Regulated Power Supply Resistor Ammeter Bread Board Multimeter

Type Variable Carbon Moving Coil

Range (0-30)V 1k,2.2k (0-50)mA

Quantity 2 2,2 1 1

THEORY:Theorem is designed to simplify networks containing two or more sources. It states that in a network containing more than one source, the current at any one point is equal to the algebraic sum of the currents produced by each source acting separately. The superposition theorem for electrical circuits states that the response (Voltage or Current) in any branch of a bilateral linear circuit having more than one independent source equals the algebraic sum of the responses caused by each independent source acting alone, while all other independent sources are replaced by their internal impedances.

To ascertain the contribution of each individual source, all of the other sources first must be "turned off" (set to zero) by: 1. Replacing all other independent voltage sources with a short circuit (thereby eliminating difference of potential. i.e. V=0, internal impedance of ideal voltage source is ZERO (short circuit)). 2. Replacing all other independent current sources with an open circuit (thereby eliminating current. i.e. I=0, internal impedance of ideal current source is infinite (open circuit). This procedure is followed for each source in turn, then the resultant responses are added to determine the true operation of the circuit. The resultant circuit operation is the superposition of the various voltage and current sources.

PROCEDURE:1. Connections are made as per circuit diagram 2. The ammeter readings are noted down which are I1 &I2 3. Figure 1 shows a circuit with two sources V1 and V2 4. Take the reading current I through load R 5. Now switch off V2 and Short circuit the 2 Terminals 6. Measure the current I, through the load R. 7. Insert V2 and switch off V1, by short circuit the 2 terminals and again measure the current and verify I=I+I

RESULT:

Thus the superposition theorem is verified practically and theoretically.

CIRCUIT DIAGRAM Step 1

R1 1k

R2 1k

(0-30)V 1 AM 1 +

R3 2.2k

A

Step II

R1 1 k R3 2.2k

R1 2 k R4 2.2k

(0 0 1 -3 )V A 1 M +

A

Step IIIR1 1k R2 1k

R4 2.2k (0-30)V 2

+ (0-30)mA

R3 2.2k

A

R4 2.2k (0-30)V 2

TABULAR COLUMN

Vs1(V) Vs2(V) IL(mA)

Vs1 active and Vs2 short circuit (II) Vs1(V) IL(mA)

Vs2 active and Vs1 short circuit (III) Vs1(V) IL(mA)

Total current(mA)

IL from TAB(mA)

Values Theoretical

I1(mA )

I2(mA )

I(mA)

Practical

Ex. no: 4 DATE:

VERIFICATION O

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