statically induced EMF
In this section we will see about statically induced EMF. EMF means electromotive force.
The induced EMF is basically static induced EMF and dynamically induced EMF. In statically induced EMF, conductor is stationary that means the conductor is not moving. Also there is no any physical change in magnetic field.
 |
| Statically induced EMF |
The Principle of statically induced EMF
The magnitude of current which produce magnetic field that are links with the conductor is change with respect to time.
To produce electromotive force statically its required to generate alternating flux by alternating current source.
This alternating current produce alternating flux which pass through low reluctance path and link with another coil and because of this linkage EMF is induced in that coil.
There are different type of statically induced EMF
• Self induced EMF
• Mutual induced EMF
Self induced EMF
See the below diagram that will help us understand the concept of self induced EMF. In this diagram coil is mount on magnetic core. Voltage source is connected to this coil with series variable resistance adjust current flowing through a coil. |
| Self induced EMF |
- Just imagine current is flowing through this coil and due to this current flux lines are produced surrounding that coil. This flux lines are changing in nature with time.
- That flux linkage with coil is the product of number of turns into flux lines.
- Current constantly flow through this coil, if we change this resistance the current will change due to that flux produced due to the soil is also changes.
- Due to that changing flux EMF is induced in the coil explain the Faraday’s law of electromagnetic induction. This EMF is called as self induced EMF and this phenomenon is called self induction.
- The self induced EMF is generate when current through a coil changing nature.
Application of self induced emf
• Choke used in fluorescent tube
• Filter choke used in the rectifier circuit
1.Self inductance
According to lenz's law of electromagnetic induction direction of induced current or emf is opposed to main current flowing through this coil by which this induced EMF is generated.
We know that induced EMF is trying to oppose to the change in current that means it is trying to maintain the constant current in that coil. if the coil current increase self-induced EMF will try to to reduced that current and also if the current decrease in that coil self induced EMF will try to oppose this decreasing nature that means the induced EMF will trying to increase the the current in that coil.
This is indicated that the induced EMF always trying to oppose to change in current through the coil.
The property of that induced EMF to oppose any change in in current flowing is know as self inductance.
2.Mutually induced emf
The diagram below shows the mutual induction between two coils c1 and c2
 |
| Mutual induction |
Consider two coil placed near each other that one coil C1is primary and another coil C2 secondary
When we connect AC supply source to the primary winding it will produce alternating magnetic field, that magnetic field link with secondary and in secondary winding c2 EMF is induced that EMF is called as mutual induced EMF. And this all phenomenon is called as mutual induction.
Application of mutually induced EMF
• Transformer
When videos AC supply to the primary winding of the transformer EMF is induced in secondary winding without any physical contact intech process or feminine is called as mutual induction• Induction motor
Similar like a transformer when we gives supply to the stator winding EMF is induced in rotor winding that is mutual induced EMF
No comments:
Post a Comment