In this article we will learn about the electromagnetic induction, we will also know about the right hand rule, left hand rule, helix rule .
Electromagnetic induction
Whenever a conductor cuts the magnetic lines of forces, then an EMF is induced in the conductor. This is called electromagnetic induction. Thus, electromagnetic induction. Thus, electromagnetic induction is the phenomenon of production of electric current (or EMF) in a coil, when the magnetic flux linked with the coil is changed.
This principle was given by Michael Faraday and is used in DC generators.
The two law given the basic electromagnetic induction are discussed below.
Faraday’s Law of Electromagnetic induction
With reference to electromagnetic induction, Michael Faraday has given two laws,
They are as follows.
First Law of electromagnetic induction
Whenever the value of magnetic flux passing through any conductor gets changed, then an EMF is generated in the conductor and this EMF generated is retained until the value of flux is variable.
Second Law Of Electromagnetic induction
The induce EMF , in any closed circuit is equal to the time rate of change of magnetic flux linkage with the circuit.
LenZ’s Law of Electromagnetic Induction
This law gives the direction of induced emf/current. According to this law,
“ the direction of induced EMF or induced current in a circuit is such as to oppose the change in magnetic flux flux which produces it”.
Electromagnetism
Out of three effects ( that is heating, chemical and magnetic) of electric current, one is magnetic effect of electric current. In the year 1819, scientist named orested propounded that, if a magnetic needle is placed near a wire carrying current then the needle is affected by electric current or in other words, a current carrying conductor produces magnetic field.
In this way, the magnetic field produced by a current carrying conductor is called as electromagnetism.
The magnetic filed produced by different types of current carrying conductors are given below.
Magnetic filed of Current Carrying Straight Conductor
The magnetic field around a current carrying straight conductor is concentric magnetic lines around the conductor. The center of magnetic lines are produced along the complete length of the conductor.
The direction of electric lines of forces can be found by following two methods.
Right Hand Rule
According to this rule, hold the current carrying conductor in the right hand such that the thumb pointing in the direction of current and parallel to the conductor, then curled fingers point in the direction of magnetic field or flux around it.
Cork Screw Rule
Imagine a right handed screw to be along the conductor carrying current with its axis parallel to the conductor and tip pointing in the direction of the current flow.
Then, the direction of magnetic filed is given by the direction in which the screw must be turned so as to advance in the direction of the current.
Magnetic Field of a current carrying Loop
Magnetic field in a current carrying conductor is also made of concentric spherical magnetic lines.
The difference is that, inside the loop, these electric lines are concentrated and outside the loop, they are at some distance from each other.
Magnetic Field of a Current carrying solenoid
For know better about the electromagnetic induction we need to know about the magnetic field in circuit or coil.
The magnetic field of a current carrying solenoid or a coil is similar to the magnetic field of a bar magnet.
One end of solenoid works as a north pole and other end as south pole.
The poles of a solenoid can be pointed out by any of the following rules.
Helix Rule
According to this rule, if the solenoid is held in such a way that curled fingers represent the direction of current, then right hand thumb or outer stretched points towards North pole.
End Rule
If on observing, we find from one pole, the direction of solenoid current is clockwise then, that pole is south pole and if current direction is anti-clockwise then it is north pole.
Hence it is the Faraday law of electromagnetic induction if you will find any incorrect above please you must comment below in comment box