PHYSICS INVESTIGATORY

PROJECT

Electromagnetic Induction

SUBMITTED TO: SUBMITTED BY:

Ms Nirmala Aditya Sharma

PGT Physics XII Science

CERTIfICATE

This is to certify that ADITYA SHARMA, student of CLASS 12th, K. V. NO:4, JALANDHAR CANTT has completed the project titled “ELECTROMAGNETIC INDUCTION” under my guidance and completed it to my satisfaction. To the best of my knowledge, the present work is the result of his original investigation and study.

Ms Nirmala

PGT Chemistry

ACKNOWLEDGEMENT

It gives me a great pleasure to express my

gratitude towards our physics teacher Ms

NIRMALA for his guidance, support and

encouragement throughout the duration of the

project. Without his motivation & help, the

successful completion of this project would not

have been possible. I would also like to express

my gratitude to the lab assistant Mr. GURMEET

SINGH for his support .

TABLE Of CONTENTS

Introduction

Objective

Apparatus required

Theory

Conclusion

References

INTRODUCTION

Faraday’s Law of Electromagnetic Induction:

It is a basic law of electromagnetism predicting how a

magnetic field will interact with an electric circuit to

produce an electromotive force (EMF). It is the fundamental

operating principle of transformers, inductors and many

types of electrical motors and generators. Faraday explained

electromagnetic induction using the concept of lines of

force. These equations for electromagnetic induction are

extremely important since they provide a means to precisely

describe how, many natural physical phenomena in our

universe and behave.

The ability to quantitatively describe physical phenomena

not only allows us to gain a better understanding of our

universe, but it also makes possible a host of technological

innovations that define modern society. Understanding

Faraday’s laws of electromagnetic induction can be

beneficial since so many aspects of our daily life function

because of the principles behind Faraday’s law. From

natural phenomena, such as the light we receive from the

sun, to technologies that improve our quality of life, such as

electric power generation, Faraday’s law has a great impact

on many aspects of our lives.

(a)Representation of magnetic fields inside a solenoid(b) Cross-sectional view

Faraday’s law describes electromagnetic induction.

Whereby an electric field is induced, or generated by a

changing magnetic field.

In Faraday’s first experimental demonstration of

electromagnetic induction, he wrapped two wires around

opposite sides of an iron ring or ‘torus’ to induce current.

Faraday’s law is a single equation describing two different

phenomena: the motional EMF generated by a magnetic

force on a moving wire, and the transformer EMF generated

by an electric force due to a changing magnetic field.

Electromagnetic Induction

APPARATUS REQUIRED

Insulated Copper wire

An iron rod

A strong magnet

A light emitting Diode (LED)

OBJECTIVE

To determine the Faraday’s law of electromagnetic

induction using a copper wire wound over an iron rod and a

strong magnet.

THEORY

The magnetic flux ( or B) through a surface is the

component of the magnetic field passing through the

surface. The SI unit of magnetic flux is weber (Wb), and the

COGS unit is maxwell.

Magnetic flux is usually measured with a flux meter, which

contains measuring coils and electronics that evaluate the

change of voltage in the measuring coils to calculate the

magnetic flux.

If the magnetic field is constant, the magnetic flux passing

through a surface of vector area S is

Where is the magnitude of magnetic field having the unit of Wb/m2(T). is the area of the surface and is the angle between magnetic field lines and the normal.For a varying magnetic field, we first consider the

magnetic flux through a small amount of area where we

may consider the magnetic field to be constant.

From the magnetic vector potential and the

fundamental theorem of the curl, the magnetic field

may be defined as

where the line integral is taken over the boundary of the surface, which is denoted as

LAW

The most widespread version of Faraday’s law of

electromagnetic induction states that

“The induced electromotive force in any closed surface is

equal to the negative of the rate of change of magnetic

flux through the circuit.”

This version of Faraday’s law strictly holds true only when

the closed circuit is a loop of infinitely thin wire, and is

invalid in other circumstances as discussed below. A

different version, the Maxwell-Faraday equation is valid in

all circumstances.

The magnetic flux ( ) changes due to the change in magnetic field.

Faraday’s law of electromagnetic induction states that the

wire loop acquires an EMF, defined as the energy

available per unit charge that travels once around the

wire loop.

Equivalently, it is the voltage that would be measured

by cutting the wire to create an open circuit. And

attaching a voltmeter to the leads.

According to Lorentz force law,

And the EMF of the wire loop is

where (i) is the electric field

(ii) is the magnetic field

(iii) is the infinite length along the wire

And the line integral is evaluated along the wire.

The Maxwell-Faraday equation states that a time

varying magnetic field is always accompanied by

spatially varying, non-conservative electric field and

vice versa. The Maxwell-Faraday equation is

CONCLUSION

Faraday’s law of electromagnetic induction, first

observed and published by Michael Faraday in the mid-

nineteenth century, describes a very important

electromagnetic concept. Although its mathematical

representations are cryptic, the essence of Faraday’s

law is not hard to grasp. It relates an induced electric

potential or voltage to a dynamic magnetic field. This

concept has many far reaching ramifications that touch

our lives in many ways: from shining of the sun to

electricity and power in our homes. We can all

appreciate the profound impact Faraday’s law has on

us.

REFERENCES

LABORATORY MANUAL OF CHEMISTRY

www.wikipedia.com

www.howstuffworks.com

www.scienceforall.com

www.100scienceprojects.com

Google images