ELECTROMAGNETICINDUCTION

1. Name :MoumitaBasak
Class : 12th
science
Roll No. : 6636601

2. ELECTROMAGNETICINDUCTION

3. INDEX:
Aim
Certificate
Acknowledgement
Apparatus
Introduction

4. Theory
Conclusion
Bibliography

5. AIM:
To determine the faraday’s
law of electromagnetic
induction using a copper
wire wound over an iron rod
and a strong magnet

6. CERTIFICATE
This is to certify that the PHYSICS project titled
‘ELECTROMAGNETIC INDUCTION’ has been
successfully completed by MOUMITA BASAK of
Class XII in partial fulfillment of curriculum of CENTRAL
BOARD OF SECONDARYEDUCATION (CBSE) leading
to the annual examination of the year 2015-2016.
INTERNAL EXAMINER TEACHER IN-CHARGE

7. ACKNOWLEDGEMENT
It gives me great pleasure to express my gratitude
towards our Physicsteacher MR.NALINI
PRADHANfor his guidance, support and
encouragement throughout the duration of the
project. Without his motivation and help the
successful completion of this project would not
have been possible. I would also take this
opportunity to thank our principal .MRS. GLORIA
MINJ for encouraging me.

8. BIBLIOGRAPHY
• WIKIPEDIA
• HOW STUFF WORKS
• SCIENCE FOR ALL

9. APPARATUS
1. Insulated copper wire
2. A iron rod
3. A strong magnet and
4. A light emitting diode
(LED)

10. INTRODUCTION:
araday's law of induction is a basic law of electromagnetism that predicts
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.
F
Electromagnetic induction was discovered independently by Michael
Faraday and Joseph Henry in 1831; however, Faraday was the first to publish the
results of his experiments. Faraday explained electromagnetic induction using a
concept he called lines of force.These equations for electromagnetics are extremely
important since they provide a means to precisely describe how many natural
physical phenomena in our universe arise 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 Law 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.
Faraday’s Law is the result of the experiments of the English chemist and physicist
Michael Faraday . The concept of electromagnetic induction was actually discovered
simultaneously in 1831 by Faraday in London and Joseph Henry, an American
scientist working in New York , but Faraday is credited for the law since he published

11. his work first . An important aspect of the equation that quantifies Faraday’s Law
comes from the work of Heinrich Lenz, a Russian physicist who made his
contribution to Faraday’s Law, now known as Lenz’s Law, in 1834 (Institute of
Chemistry).
Faraday’s law describes electromagnetic induction, whereby an electric field is
induced, or generated, by a changing magnetic field. Before expanding upon this
description, it is necessary to develop an understanding of the concept of fields, as
well as the related concept of potentials.
Faraday's first experimental demonstration of electromagnetic induction (August 29,
1831), he wrapped two wires around opposite sides of an iron ring or "torus" (an
arrangement similar to a modern toroidal transformer) to induce current
Figure 1 Faraday's First Experiment
Some physicists have remarked that Faraday's law is a single equation describing two
different phenomena: the motional EMF generated by a magnetic force on a moving
wire (see Lorentz force), and the transformerEMF generated by an electric force due
to a changing magnetic field (due to the Maxwell–Faraday equation). James Clerk

12. Maxwell drew attention to this fact in his 1861 paper On Physical Lines of Force. In
the latter half of part II of that paper, Maxwell gives a separate physical explanation
for each of the two phenomena. A reference to these two aspects of electromagnetic
induction is made in some modern textbooks.

13. THEORY:
Magnetic flux:
The magnetic flux (often denoted Φ or ΦB) through a surface is the component of
the B field passing through that surface. The SI unit of magnetic flux is
the weber (Wb) (in derived units: volt-seconds), and the CGS unit is the maxwell.
Magnetic flux is usually measured with a fluxmeter, which contains measuring coils
and electronics that evaluates 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 B is the magnitude of the magnetic field (the magnetic flux density) having the
unit of Wb/m2
(Tesla), S is the area of the surface, and θ is the angle between the
magnetic field lines and the normal (perpendicular) to S.
For a varying magnetic field, we first consider the magnetic flux through an
infinitesimal area element dS, where we may consider the field to be constant

14. :
From the definition of the magnetic vector potential A and the fundamental theorem
of the curl the magnetic flux may also be defined as:
where the line integral is taken over the boundary of the surface S, which is denoted
∂S.

15. LAW:
The most widespread version of Faraday's law states:
The induced electromotive force in any closed circuit is equal to the
negative of the time rate of change of the magnetic flux through the
circuit.
This version of Faraday's law strictly holds 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 (discussed below), is valid in all
circumstances.
When the flux changes—because B changes, or because the wire loop is moved or
deformed, or both—Faraday's law of induction says that the wire loop acquires
an EMF , defined as the energy available per unit charge that travels once around
the wire loop (the unit of EMF is the volt).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 theLorentz force law (in SI units),
the EMF on a wire loop is:

16. where E is the electric field, B is the magnetic field (aka magnetic flux density,
magnetic induction), dℓ is an infinitesimal arc length along the wire, and the line
integral is evaluated along the wire (along the curve the conincident with the shape of
the wire).
The Maxwell–Faraday equation states that a time-varying magnetic field is always
accompanied by a spatially-varying, non-conservative electric field, and vice-versa.
The Maxwell–Faraday equation is
where is the curl operator and again E(r, t) is the electric field and B(r, t) is
the magnetic field. These fields can generally be functions of position r and time t.
The four Maxwell's equations (including the Maxwell–Faraday equation), along with
the Lorentz force law, are a sufficient foundation to derive everything inclassical
electromagnetism. Therefore it is possible to "prove" Faraday's law starting with
these equations. Faraday's law could be taken as the starting point and used to
"prove" the Maxwell–Faraday equation and/or other laws.)

17. CONCLUSION
Faraday’s Law of Electromagnetic Induction, first observed and
published by Michael Faraday in the mid-nineteenth century,
describes a very important electro-magnetic concept. Although its
mathematical representations are cryptic, the essence of Faraday’s
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 the
shining of the sun, to the convenience of mobile communications, to
electricity to power our homes. We can all appreciate the profound
impact Faraday’s Law has on us.

18. EXPERIMENT PHOTOs