This Slide is about the Electromagnetic Induction System, who people don't know about that system it will help them some basic ideas about Induction system. Now a days we are looking for alternate fuel to protect our environment form pollutions that why we can use the Induction motor for operate our vehicle, as we will use this system for our daily works we have to know about this one.............

2. Here, I am trying to present about
Electromagnetic Induction.

3. OBJECTIVES:-
(note: they are very shortly briefed )
• After complete that lecture we will be able to:-
• Get some information about Electromagnetic
Induction system.
• What are the requirements for Electromagnetic
Induction.
• We will know about the amount of Induced e.m.f.
• We will know about Faraday’s low of Electromagnetic
Induction.
• Direction of Induced e.m.f. (Lenz’s Law & Fleming
Right Hand Rule)

4. 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.

5. The basic Requirements for
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 ass this
change is taking place.

6. Some other important Requirements
are……………
• 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.
• No change of Flux ,No e.m.f. Induced in the coil.
• The change of Flux linking with the conductor and
Flux can be cutting in two ways:-

7. • 1) One of them The conductor will moved and
the magnetic field will Stationary. Use that system
the DC generator works.

8. 2) Secondly, The conductor will stationary and
the Magnetic field will be moved. That is used
for the AC generator.

9. • The term N is called flux linkages with Coil.
Thus emf induced in a coil is directly
proportional to the rate of change of flux
linkages. In the same rate of changes flux if we
increase the turn of coil then the rate of induced
emf will be increase.

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

11. 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:-
• First Law:
• “When the Changes Flux linking with a conductor
or coil, an emf is Induced in it.”
• Second Law:
“The magnitude of induced emf in a coil is directly
proportional to the rate of change of flux
linkages”

12. • Induced emf  Rate of change of flux linksges.
• Consider a magnet approaching towards a coil. Here we consider two
instants at time T1 and time T2.
Flux linkage with the coil at time, T1 = NΦ1 Wb
Flux linkage with the coil at time, T2 = NΦ2 wb
Change in flux linkage = N(Φ2 – Φ1)
Let this change in flux linkage be, Φ = Φ2 – Φ1
So, the Change in flux linkage = NΦ
Now the rate of change of flux linkage = NΦ / t
Take derivative on right hand side we will get
The rate of change of flux linkage = NdΦ/dt
But according to Faraday’s law of electromagnetic induction the rate
of change of flux linkage is equal to induced emf

13. Direction of Induced emf and Current:
• 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.
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:-

14. “An Induced Current will flow in such a
Direction so as to oppose the cause that
produces it.”
• 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.

15. • 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.

16. 2) 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.

17. • “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.”

18. • Explanation of Fleming’s Right 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.

19. • Let, ABCD is a conductor and it is moving through in Clock
wise direction magnetic flux’s are going from north pole to
south pole. When the conductor is moving flux is cutting by it.
When flux is cutting emf is induced by conductor. On the time
ABCD conductor is in vertical position flux is cutting and emf
induced from
DCBA in conductor and it is passing through by the
Commutator, the conductor have two terminals
there have two carbon
brush with two
commutators.
Commutator is moving
With the conductor and
induced emf (Current) is
passing through by
carbon
brush to the circuit.

20. After moving sometimes the conductor will in
parallel condition, so no flux will be cut by the
conductor and no emf will induced in conductor.
So, no current will flow. Again when the conductor
will be in vertical position on this time magnetic flux
will be cut by conductor but this time will be flow
the negative current by conductor. And current will
be flow from ABCD. The current flowing curve for a
full cycle will be like the showing in the figure. That
getting current is called AC current.