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7/29/2019 Arpan Bhasker

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Presented by

ARPAN BHASKAR

CHADAR

Class12 B


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To investigate therelation betweenthe ratio of

i. Input and outputvoltage and

ii. Number of turns inthe secondary coil andprimary coil of a self

designed tranformer.


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MATERIAL REQUIRED

Iron rod

Copper wires (of different diameters)

Two a.c. voltmeters

Two a.c. ammeters.


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CIRCUIT DIAGRAM


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THEORY

The working of a transformer is based on mutual inductionphenomena. Let an ideal transformer in which the primary andsecondary coil have negligible resistance and all the flux in the

ore links both primary and secondary windings.The induced emf in the primary coil

(p)=-N(p)d/dt

The induced emf in the secondry coil,(s)=-N(s)d/dt

Where the is the electromagnetic flux linked with each turn ofprimary and secondry coil at a time of time t ,then

S/ P =N(s)/N(p)=K=Transformer ratio

For an ideal transformer , there is no loss of energy ,thenInput power=output powerI(p)/I(p) =(s)/ (p)=K


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SOME APPLICATIONS OF

TRANSFORMERS Thermal power stations - Hydraulic power stations -

Photovoltaic power stations

Energy supply to static frequency converter - Rail ways

Marine Electrolysis - Oil production Feeding - Interconnection autotransformer - Motor

starting autotransformer

SOME APPLICATIONS FOR TRANSFORMERS

THERMIC POWER STATIONS The transformer steps up the generator voltage

(400V or 690V for low power stations, 6.3kV or

11kV for higher power stations) in order to

adapt it to the network voltage (generally 20kV)


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STEP UP TRANSFORMER

The primary coil is made of thick wire.

It increases the alternating voltage.(Es>Ep)


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STEP DOWN TRANSFORMER

The secondary coil is made of thick wire.

It desreases the alternating voltage (Es


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PROCEDURE

Take thick iron rod and cover it with a thick paper and wind a largenumber of turns of thin Cu wire on thick paper. This constitutesprimary coil of the transformer.

Cover the primary coil with a sheet of paper and wound relatively

smallar number of turns of thick Cu wire on it. This constitutessecondary coil of the transformer. Connect P1 P2 to a.c.mains (220v) and measure the input voltage

and current,using a.c. voltmeter and ammeter respectivly. Similarly measure the output voltage and current through S1 S2 . Now connect the S1 S2 to a.c. mains and again measure voltage

and current through primary and secondary coil of step uptransformer. Repeat all steps for other self made transformer by changing

number of primary turns and secondary turns in coil.


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OBSERVATIONS

Least count of a.c. volt meters = v

Zero error volt meter = v

Range of volt meter = v

L.C. of a.c. ammeter = A

Zero error ammeter = AApplied a.c. voltage = v


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S.no.

1

No. ofprimarycoilsN(p)

2

No. ofturns insecondary coil

N (s)3

Voltageinprimarycoil E(f)

4

Currentin p.coilI(2)

5

Voltageinsecondary coil

E(s)6

Currentinsecondary coil

I(s)7

Loss ofpowerB

8

1.

2.

3.

4.

5.

OBSERVATION TABLE


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CONCLUSION

1.The output voltage of the transformeracross the secondry coil depends upon the

ratio (Ns/Np) w.r.t input voltage .2.The output current of the transformer

across the secondry coil depends upon theturn ratio (Ns/Np) w.r.t input current .

3.There is loss of power between input andoutput coil of a transformer.


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PRECAUTIONS

1.Keep your self from the high voltage .

2.While taking the the reading of current

and voltage ,the a.c main supply shouldremains constant.


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SOURCE OF ERROR

1.Value of currents can be changed due toheating effect of current .

2.The eddy current can change the reading.


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