PPT consists brief explanation of about electromagnetic induction

1. PREPARED BY - SAKSHI
BPT (2017-21)

2.  Electromagnetic induction was discovered by Michael Faraday.
 Electromagnetic induction is the production of voltage or electromotive force due to a change in
the magnetic field.
 The induced voltage in an electromagnetic induction is described by the following equation as:
Ɛ = N(dΦ/dt)
Where
e = voltage induced (measured in volts)
t = time (measured in seconds)
N = number of turns found in the coil
Φ = magnetic flux

3.  Many types of electrical equipment such as motors, generators and transformers
function based on the principle of the electromagnetic induction.

4.  Lenz's law states that the direction of induced emf is such that it tends to
produce a current in the coil which opposes the change in magnetic flux
producing it.
 If the current is induced due to change in current in the primary coil, then
induced current is such that it tends to stop the change.
 It is based on the principle of conservation of energy.
Explanation-
If the induced current creates a magnetic field which is equal and opposite to the direction
of magnetic field that creates it, then only it can resist the change in the magnetic field in the
area.Thus, Lenz’s law is in accordance with the law of conservation of energy.

5. INDUCTOR:
Inductor is a coil that stores electrical energy in a magnetic field when electric current flows through it.
INDUCTANCE:
 Inductance is the ability of an inductor to store energy in a magnetic field.
 It is caused by the magnetic field generated by electric currents flowing within an electrical circuit.
 The henry (symbolized H) is the Standard International ( SI ) unit of inductance.
 There are two ways in which inductance is used:
 Self-inductance - It is the property of the coil due to which it opposes the change of current flowing
through it.
 Mutual-inductance - It is the property of the coil due to which it opposes the change of current in the
other coil.

6.  Air Core Inductor
 Iron Core Inductor
 Ferrite Core Inductor
 Laminated Core Inductor
 Toroidal Inductor
 Iron powder Inductor
 Coupled Inductor
 Molded Inductors
 Variable Inductors

7. • Reactance is the effective resistance offered by an inductor or capacitor in an circuit.
• denoted by : X
Formula of inductive reactance Formula of capacitive reactance
XL= 2πfL XC= 1 / (2πfC)
Where: Where:
XL = inductive reactance in ohms(Ω) Xc = capacitive reactance in ohms(Ω)
L = inductance in henries C= capacitance in farads
π = Greek letter Pi
f = frequency in Hz

8.  Impedance is an expression of the total opposition that an
electronic component or circuit offers to alternating or direct
electric current.
 Impedance is a vector (two-dimensional) quantity consisting of
two independent scalar (one-dimensional) phenomena:
resistance and reactance.
 denoted by : Z
 In case of an A.C. circuit having L , C & R in series. The total or
effective hindrance of the circuit is called Impedenace (Z).

9.  Impedance in LCR circuit can be calcuted by:
 where:
 R-resistance of resistor
 XL - inductive reactance
 Xc - capacitiv e reactance
tan ɸ = XL－Xc / R
where ɸ is phase difference between current and voltage
PHASOR
DIAGRAM