This document is a presentation on electromagnetic induction and its applications by a group of students. It discusses the history of electromagnetic induction discovered by Faraday, defines electromagnetic induction as occurring when a changing magnetic flux induces an emf in a conductor, and outlines Faraday's laws of electromagnetic induction. It also explains Lenz's law and Fleming's right hand rule for determining the direction of induced current. Finally, it provides examples of useful applications of electromagnetic induction such as AC generators, electric motors, magnetic recording devices, electric stoves, and magnetic brakes.

1. Electromagnetic Induction & Its
Applications
PHY123 Presentation
Group: ASTUTE
• Tasnuva Tabassum Oshin: 151-15-4673
• Masumer Rahman: 151-15-5040
• Mariya Rahman: 151-15-5317
• T.M Ashikur Rahman: 151-15-4971
• Soummo Suprya: 151-15-4741
• Md. Fazle Rabbi Ador: 151-15-5482

2. introduction
History of Electromagnetic Induction.
What is Electromagnetic Induction?
Requirements of Electromagnetic induction
Amount of Induced e.m.f.
Faraday’s Law of
Electromagnetic Induction
Direction of Induced emf and Current
Lenz’s Law
Direction of Induced emf and Current
Fleming’s Right Hand Rule
Useful applications

3. • SoummoSupriya
151-15-4741

4. History ofElectromagnetic Induction
*Almost 200 years ago, Faraday looked for evidence that a
magnetic field would induce an electric current with this
apparatus.
*He found no evidence when the magnet was steady, but did
see a current induced when the magnet moves up and down .

5. Faraday learned that if you change any part of the flux
over time you could induce a current in a conductor
and thus create a source of EMF (voltage, potential
difference).
History ofElectromagnetic Induction

6. What is Electromagnetic Induction?
When the Magnetic flux linking with a conductor or coil and
changes an e.m.f. is induced in the conductor. If the conductor
forms a complete loop or circuit, a current will flow in it,
that’s called the Electromagnetic Induction.

7. • T.M.Ashikur Rahman
151-15-4971

8. Requirements of Electromagnetic induction
1) The first and basic requirement for
electromagnetic induction is the change in Flux
linking with the conductor (or coil).
2) The e.m.f. and hence the current in this conductor
(or coil) will persist so long as this change is taking
place.
3)The requirement is not only linking the coil with
the Flux, the main thing is, if we want to induced
some e.m.f. The Flux should be change after linking
with coil.

9. Amount of Induced e.m.f:
The amount of induced e.m.f. in a coil
is directly proportional to----
1) the number of turn on the coil,
2) the rate change the Flux linking with
coil.

10. Amount of Induced e.m.f:
t
NN
t
N
eortheChangTimeTakenf
uxChangeofFl
N
geofFluxrateofChanN
12
)12(








Induced emf is
Here,
N= Number of Turn of Coil
= the change of Flux linking by conductor
t= time of changing the flux

11. • Masumer Rahman
151-15-5040

12. Faraday’s Law of
Electromagnetic Induction:-
Faraday performed a series of
experiments to the phenomenon of
electromagnetic induction. He performed
two laws about electromagnetic induction
a known as Faraday’s law:-

13. Faraday’s Law of
Electromagnetic Induction:-
First Law:
“When the Changes Flux linking with a
conductor or coil, an emf is Induced in
it.”

14. Faraday’s Law of
Electromagnetic Induction:-
Second Law:
“The magnitude of induced emf in a coil is
directly proportional to the rate of change
of flux linkages”

15. Mariya Rahman
151-15-5317

16. The direction of Induced emf and
hence current in conductor or coil can
be determined by one of the following
methods:
1. Lenz’s Law
2. Fleming’s Right hand Rule.
Directionof Inducede.m.f andCurrent
Lenz’s Law

17. 1) Lenz’s Law:- Email Lenz, observed that the direction of
induced emf has a defined relation to change of magnetic
field that produces it. He gave the simple following simple
rule:-
“An Induced Current will
flow in such a Direction
so as to oppose the cause
that produces it.”
Directionof Inducede.m.f and Current
Lenz’s Law

18. • The cause that the change of produces current is
the change of flux linking the coil. Therefore, the
direction of induced current will be such that its
own magnetic field oppose the change in flux that
produced the induced current.
• That means the induced current on its conductor
or coil will be the oppose direction of the original
flux direction.
Directionof Inducede.m.f and Current
Lenz’s Law

19. We know that, the magnetic flux always flow through from
North pole to South pole. So, Current will be flow through
from South to North.
Directionof Inducede.m.f and Current
Lenz’s Law

20. TasnuvaTabassumOshin
151-15-4673

21. DirectionofInduced emfand Current
Fleming’s Right Hand Rule
• This is the Rule of particularly suitable to find the
direction of Induced emf and hence current when
the conductor moves at right angles to a
stationary magnetic field.
• Stretch out the Four finger, Middle finer and
thumb of Your right hand so that they are at right
angles to one another.

22. DirectionofInduced emfand Current
Fleming’s Right Hand Rule
“If the forefinger points to direction of the magnetic field,
Thumb is the direction of motion the conductor, then the
middle finger will point in the direction to the Induced
Current.”

23. DirectionofInduced emfand Current
Fleming’s Right Hand Rule
Consider that, A Conductor is Moving as the direction of Forefinger, the
magnetic flux is go through from the north to south pole as the same
direction of Thumb finger, now Current will be flow as the same
direction of the middle finger.

24. Md.Fazle RabbiAdor
151-15-5482

25. Useful applications

26. AC Generator
AC Generators use
Faraday’s law to
produce rotation and
thus convert electrical
and magnetic energy
into rotational kinetic
energy. This idea can be
used to run all kinds of
motors.

27. Electro magnetic
induction can
create an
electrical motor
by passing a
current through a
set of electro-
magnets
mounted on a
rotating shaft.
ELECTRIC MOTOR

28. MAGNETIC RECORDS
Write data by
magnetizing recording
media (e.g., video tape,
hard disk) using
electromagnets.
Data is read back using
the induced current
produced when
magnetized media moves
past receiver coils
(reverse of writing data).

29. ELECTRIC STOVES
The water in the metal pot is
boiling. Yet, the water in the
glass pot is not boiling, and
the stove top is cool to the
touch. The stove operates in
this way by using
electromagnetic induction.

30. MAGNETIC BRAKES
Great America’s
Drop Zone has a 22
story free fall,
lasting four
seconds,
decelerated by
magnetic braking.

31. QUESTION??
?