1. Kamla Nehru Hr. Sec. school,
2014-2015
INVESTIGATORY PROJECTS
NAME:- Shivansh patel
CLASS:- XI ‘D’
SUBJECT:- Physics
ROLL NO.:- 11426
TOPIC:- Electromagnetic induction
SUBMMITED TO :- SUBMMITED BY:-
Mr.Prabhakar jaiswal Shivansh patel
(Physics teacher)

2. PHYSICS INVESTIGATORY
PROJECT
)

3. INDEX:
Aim
Apparatus
Introduction
Theory
Conclusion
Bibliography

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

5. ACKNOWLEDGEMENT
It gives me great pleasure to express my gratitude towards
our Physics teacher MR. Prabhakar jaiswal for 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.
Shivansh patel

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

7. 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.
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
F

8. 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.

9. 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 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).

10. 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

11. 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 transformer EMF generated by an electric
force due to a changing magnetic field (due to the
Maxwell–Faraday equation). James Clerk
Maxwell drew attention to this fact in his 1861
paper On Physical Lines of Force. In the latter half of

12. 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.

14. 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
:

15. 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.

16. LAW:
The most widespread version of Faraday's law
states:-
The induced electromotive force in any closed circuit is equal to
the negativeof 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

17. 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 the Lorentz force law (in SI units),
the EMF on a wire loop is:
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

18. 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.

19. 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.)

20. 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 impactFaraday’sLaw hason us.

21. BIBLIOGRAPHY
 WIKIPEDIA
 HOW STUFF WORKS
 SCIENCE FOR ALL