PHYSICS PROJECT pdf.pdf

PHYSICS
INVESTEGTORY
PROJECT
SUBMITTED BY :
ARPAN ABINASWAR
XII-C ROLL No. - 10
2022-23
L.R D.A.V PUBLIC SCHOOL
GANDARPUR , CUTTACK- 753003

INDEX/CONTENTS
2
ACKNOWLEGMENT
CERTIFICATE OF COMPLETION
ABOUT THE TOPIC
WORKING OF TRANSFORMER
VOLTAGE TRANSFORMATION RATIO
DERIVATION OF VOLTAGE TRANSFORMATION RATIO
TYPES OF TRANSFORMER
ENERGY LOSS IN TRANSFORMER
EXPERIMENT
ADVANTAGES OF TRANSFORMER
USES OF TRANSFORMER
CONCLUSION
BIBLIOGRAPHY

ACKNOWLEDGEMENT
3
I would like to express my special thanks and gratitude
to my teacher Mr.Shambhunath Mishra who gave me
the golden opportunity to do this Wonderful project
and also providing their guidance in completing this
project.
I would also like to extend my gratitude to our
respective Principal Sir Mr . Niranjan Swain for helping
us in providing different resources /materials required
for the project.

CERTIFICATE OF COMPLETION
This is to certify that the Project Report title ‘to investigate the relationship between
the outer and inner voltage and the number of turns of the secondary and primary
coil of the transformer’ is a bonafide work brought into completion by
ARPAN ABINASWAR of class XII-C of L.R D.A.V PUBLIC SCHOOL , GANDARPUR ,
CUTTACK .
4
TEACHER GUIDE
{ NAME & SIGNATURE }
DATE :
PLACE :

ABOUT THE TOPIC
4
The following project mainly speaks about the device Transformer.
A Transformer is mainly a device which transfers electric energy from
one alternating-current circuit to one or more other circuits either by
increasing(stepping up) or by decreasing (stepping down) the voltage.
POINTS TO BE HIGHLIGHTED IN THIS PROJECT:
i. Types of Transformers.
ii. Working of a Transformer.
iii. To investigate the relation between the input voltage and output
voltage and the number of turns in the secondary and primary coil
of a self designed Transformer.
iv. Advantages and Uses of Transformers.

WORKING OF A TRANSFORMER
The transformer mainly works on the principle of Faraday‘s law
of electromagnetic induction and mutual induction.
There are usually two coils Primary coil and Secondary coil on
the transformer core. The core laminations are joined in the
form of strips. The two coils have high mutual inductance.
When an alternating-current passes through the primary coil it
creates a varying magnetic flux. As per faraday’s law of
electromagnetic induction , this change in magnetic flux
induces an emf in the secondary coil which is linked to the core
having a primary coil . Thus is mutual induction.
6

7
The Transformer carries the below operations :
I) Transfer of electrical energy from circuit to
another.
II) Transfer of electrical power through
electromagnetic induction.
III) Electric power transfer without any change in
frequency.
IV) Two circuits are linked with mutual induction.

VOLTAGE TRANSFORMATION RATIO
The transformation ratio is defined as the ratio of output
voltage to the input voltage of the transformer. It gives the
information about the change in voltage level by the
transformer.
It is denoted by :
Vp/Vs = Np/Ns = k
Where, Vp=voltage on the primary side
Vs=voltage on the secondary side
Np=number of turns in the primary winding
Ns=number of turns in the secondary winding
8

DERIVATION OF VOLTAGE
TRANSFORMATION RATIO
Turn Ratio:
The turns ratio, or the turns-to-turns ratio, is the ratio of the number of turns in the
primary to the number of turns in the secondary. The turns ratio is expressed with two
numbers, like 2:1 or 2 to 1.
The first number represents the primary's relative number of turns, while the second
number represents the secondary's relative number of turns. The turns ratio of a
transformer is calculated by applying the following formula:
Np/Ns
Where , Np = number of turns in the primary winding
Ns = number of turns in the secondary winding
10

11
EMF Equation Of The Transformer :
Let , N1 = Number of turns in primary winding
N2 = Number of turns in secondary winding
Φm = Maximum flux in the core (in Wb) = (Bm x A)
f = frequency of the AC supply (in Hz)
As, shown in the fig., the flux rises sinusoidally to its maximum value
Φm from 0. It reaches to the maximum value in one quarter of the
cycle i.e in T/4 sec (where, T is time period of the sin wave of the
supply = 1/f).
Therefore,
average rate of change of flux = Φm /(T/4) = Φm /(1/4f)
Therefore,
average rate of change of flux = 4f Φm ....... (Wb/s).
Now,
Induced emf per turn = rate of change of flux per turn

12
Therefore, average emf per turn = 4f Φm ..........(Volts).
Now, we know, Form factor = RMS value / average value
Therefore, RMS value of emf per turn = Form factor X average emf per turn.
As, the flux Φ varies sinusoidally, form factor of a sine wave is 1.11
Therefore, RMS value of emf per turn = 1.11 x 4f Φm = 4.44f Φm.
RMS value of induced emf in whole primary winding (E1) = RMS value of emf per turn X Number of turns
in primary winding
E1 = 4.44f N1 Φm ............................. eq 1
Similarly, RMS induced emf in secondary winding (E2) can be given as
E2 = 4.44f N2 Φm. ............................ eq 2
from the above equations 1 and 2,
This is called the emf equation of transformer, which shows, emf / number of turns is same for both
primary and secondary winding.
For an ideal transformer on no load, E1 = V1 and E2 = V2 .
where, V1 = supply voltage of primary winding
V2 = terminal voltage of secondary winding

TYPES OF TRANSFORMER
On the basis of voltage levels there are two types of transfotmers :
i) Step Up Transformer ii) Step Down Transformer.
Step-up transformers are used between the power generator and the
power grid.
Step- down transformers are used to convert high voltage primary
supply to low voltage secondary supply.
Transformers can further be classified on the basis of medium of core,
winding arrangement, install locations.
13

14
i) STEP-UP TRANSFORMER :
Es < E so K < 1, hence N s < N p
If I p = value of primary current at the same instant
And I s = value of secondary current at this instant, then
Input power at the instant = Ep I p and Output power at the same instant = Es I s
If there are no losses of power in the transformer, then Input power = output power Or Ep I p = Es I s
Or Es / Ep = I p / I s = K
Es > E so K > 1, hence Ns > Np
As, k > 1, so I p > I s or I s < Ip
i.e. current in secondary is weaker when secondary voltage is higher.
Hence, whatever we gain in voltage, we lose in current in the same ratio.
Similarly it can be shown, that in a step down transformer,whatever we lose in voltage, we gain in
current in the same ratio. Thus a step up transformer in reality steps down the current & a step down
transformer steps up the current.
ii) STEP-DOWN TRANSFORMER :

ENERGY LOSS IN TRANSFORMEER :
Following are the major sources of energy loss in a transformer:
1. Copper loss is the energy loss in the form of heat in the copper coils of a
transformer. This is due to joule heating of conducting wires.
2. Iron loss is the energy loss in the form of heat in the iron core of the
transformer. This is due to formation of eddy currents in iron core. It is
minimized by taking laminated cores.
3. Leakage of magnetic flux - occurs in spite of best insulations. Therefore, rate
of change of magnetic flux linked with each turn of S1S2 is less than the rate
of change of magnetic flux linked with each turn of P1P2.
4. Hysteresis loss- is the loss of energy due to repeated magnetization and
demagnetization of the iron core when A.C. is fed to it.
5. Magneto striation- i.e. humming noise of a transformer.
15

16
APPARATUS REQUIRED : IRON ROD , AMMETER , VOLTMETER , COPPERWIRE .
EXPERIMENT
CIRCUIT DIAGRAM :
PROCEDURE :
1. Take thick iron rod and cover it with a thick paper and wind a large number of turns of thin
Cu wire on thick paper (say 60). This constitutes primary coil of the transformer.
2. Cover the primary coil with a sheet of paper and wound relatively smaller number of turns
(say 20) of thick copper wire on it. This constitutes the secondary coil. It is a step down
transformer.
3. Connect p1, p2 to A.C main and measure the input voltage and current using A.C voltmeter
and ammeter respectively.
4. Similarly, measure the output voltage and current through s1 & s2.
5. Now connect s1and s2to A.C main and again measure voltage and current through primary
and secondary coil of step up transformer.
6. Repeat all steps for other self made transformers by changing number of turns in primary
and secondary coil.

17
SOURCES OF ERROR : 1.Values of current can be changed due to heating effect.
2. Eddy current can change the readings.
CONCLUSION : 1. The output voltage of the transformer across the
Secondary coil depends upon the ratio (Ns/Np) with respect to the
Input voltage
2. The output voltage of the transformer across the secondary coil
depends upon the ratio (Ns/N p) with respect to the input Voltage.
3. There is a loss of power between input and output coil of a
transformer.
PRECAUTION : 1. Keep safe yourself from high voltage.
2. While taking the readings of current and voltage the A.C should
remain constant.

ADVANTAGES OF TRANSFORMERS
It‘s foremost advantage is controlling and
stabilizing the voltage transmission.
It doesn’t require any starting time.
It is highly efficient with less capital investment
and low maintenance.
They provide isolation to the ground.
There are no moving parts in Transformers.
18

USES OF TRANSFORMERS IN DAILY LIFE
Steel Manufacturing.
Alternating current regulation.
Charging batteries.
Electrolysis.
Audio Transformer.
Stabilizers.
Rectifiers.
Ammeters or current transformers.
Impedance matching., etc.
19

Conclusion
The output voltage transformer across the secondary
coil depends upon the ratio (Ns/Np) with respect to the
input voltage.
The output voltage of the transformer across the
secondary coil depends upon the ratio (Ns/Np) with
respect to the input voltage.
There is a loss of power between input and output coil
of a transformer.
20

BIBLIOGRAPHY :
The following sources are taken
fromhttps://energyeducation.cam
Besides to these the images are taken from
canstockphoto.com & Dreamstime.com.
Supportive materials are also taken from
GOOGLE, YOUTUBE., etc.
21

PHYSICS PROJECT pdf.pdf

More Related Content

What's hot (20)

Similar to PHYSICS PROJECT pdf.pdf (20)

Recently uploaded (20)

PHYSICS PROJECT pdf.pdf