PM SHRI KENDRIYA
VIDYALAYA SEONI, M.P.
Title of the Project:
“To Investigate the Relation Between the Ratio of:
1. Output and Input Voltage
2. Number of Turns in the Secondary Coil and
Primary Coil of a Self-Designed Transformer”
Submitted By: Bhargavi Nadekar
Class: 12th - ‘Science’
Roll No.: 12102
Subject: Physics
Submitted To: Mr. T.S. Rahangdale
ACKNOWLEDGEMENT
I am profoundly grateful to my Physics teacher, Mr. T. S.
Rahangdale, for their invaluable guidance, encouragement, and
support throughout this investigatory project. Their insights and
expertise made this study possible and fruitful.
I am also thankful to K V Seoni for providing the necessary
resources and laboratory facilities required for this investigation. I
would like to thank the laboratory staff for their assistance during
the setup and execution of the experiment.
Lastly, I wish to express my heartfelt thanks to my family and
friends for their motivation and support, which were instrumental
in the completion of this project.
Bhargavi Nadekar
Class XII
Roll Number: _________________
CERTIFICATE
This is to certify that Bhargavi Nadekar of Class XII, has
completed her project entitled “To Investigate the Relation
Between the Ratio of:
(i) Output and Input Voltage
(ii) Number of Turns in the Secondary Coil and Primary Coil of
a Self-Designed Transformer”
Under my supervision for the subject “PHYSICS(042) for All India
Secondary School Examination 2024- 2025”.
She has taken proper care and shown utmost sincerity in the
completion of this project. I certify that this project is up to my
expectation and as per the guidelines issued by CBSE.
Signature of Signature of
Teacher Principal
Project Report
Title:
To Investigate the Relation Between the Ratio of:
(i) Output and Input Voltage
(ii) Number of Turns in the Secondary Coil and Primary Coil
of a Self-Designed Transformer.
Objective:
1. To study the relationship between the ratio of output voltage (∆) to input voltage (∆) in a
transformer.
2. To verify that the ratio of voltages is equal to the ratio of the number of turns in the
secondary coil (∆) and the primary coil (∆).
Theory:
1. Transformer Basics:
o A transformer is an electrical device used to step up or step down AC voltages by
electromagnetic induction.
o It operates based on Faraday's law of electromagnetic induction.
2. Voltage and Turns Ratio Relationship:
o For an ideal transformer:
Where:
= Output voltage (secondary coil)
= Input voltage (primary coil)
= Number of turns in the secondary coil
= Number of turns in the primary coil
3. Efficiency Assumption:
o For this investigation, the transformer is assumed to operate ideally without
significant energy loss.
Materials Required:
1. Transformer core (iron core)
2. Copper wire (for primary and secondary coils)
3. AC power supply
4. Voltmeter
5. Ammeter
6. Rheostat (for variable resistance)
7. Connecting wires
8. Multimeter
9. Insulating tape
10. Measuring scale (to count turns of the wire)
Procedure:
1. Designing the Transformer:
o Wind the primary coil (∆) onto the transformer core with a known number of
turns (e.g., 50 turns).
o Wind the secondary coil (∆) on another section of the core with varying turns
(e.g., 20, 40, 60 turns).
o Ensure proper insulation between the two coils.
2. Connecting the Circuit:
o Connect the primary coil to the AC power supply with a rheostat in series to
control the input voltage.
o Connect the secondary coil to a voltmeter to measure the output voltage.
3. Observation for Voltage Ratio:
o Supply AC voltage (∆) to the primary coil and measure it using a voltmeter.
o Measure the output voltage (∆) across the secondary coil.
o Repeat for different turns (∆) in the secondary coil.
4. Analysis:
o Record the readings for input voltage (∆), output voltage (∆), and number of turns
(∆, ∆).
o Compare the ratio with .
Observations and Readings:
Table 1: Observations for Voltage and Turns Ratio
Serial Turns in Turns in Input Output Turns Voltage
No. Primary Secondary Voltage (Vp) Voltage (Vs) Ratio Ratio
Coil (Np) Coil (Ns) (Volts) (Volts) (Ns/Np) (Vs/Vp)
1 50 20 10 4 0.4 0.4
2 50 40 10 8 0.8 0.8
3 50 60 10 12 1.2 1.2
Graphs:
1. Graph 1:
o X-axis: Number of Turns Ratio (Ns/Np)
o Y-axis: Voltage Ratio (Vs/Vp)
o The graph should show a linear relationship.
Results:
1. The ratio of output to input voltage is directly proportional to the ratio of the number of
turns in the secondary and primary coils.
2. The experimental values closely match the theoretical expectations for an ideal
transformer.
Conclusion:
1. The investigation confirms that:
2. The designed transformer operates efficiently under the given conditions.
Precautions:
1. Ensure proper insulation of the coils to prevent short circuits.
2. Avoid overloading the transformer.
3. Take accurate measurements of voltages and turns.
4. Handle the transformer core carefully to avoid damage.
Applications:
1. Transformers are widely used in electrical power distribution systems.
2. They are essential in devices requiring voltage step-up or step-down operations.
3. Transformers play a crucial role in electronic circuits and communication systems.
