Concept of displacement current , Characteristics of displacement current

      -:Concept of displacement current:-

The concept of displacement current was given by James clerk Maxwell in 1861. He performed a experiment through parallel plate capacitor and magnetic compass.

Process:- 
                       He brought of compass niddle and placed in between parallel plate capacitor then compass niddle get deflected. This phenomena shows that there is a magnetic field between parallel plate capacitor. But in parallel plate capacitor in between plates there is dielectric material is filled. The dielectric material do not have any free charge hence there is no current between plates of the capacitor. But magnetic field is always generated by the current.

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 Maxwell's analyse that which agency is responsible for the magnetic niddle between the plates there is only one phenomena is given on charging or discharging of the plates. This phenomena is set up on time varrying electric field between plates. This time varrying electric field equivalent to the magnetic field. This field deflect the magnetic compass. Finally Maxwell concluded that that a time varrying electric field is equivalent to the magnetic field and magnetic field is equivalent to the current that current is known as displacement current it is represented by Id.
           Thus , In any circuit, total current is some of displacement current and conduction current.
                  
                         I  =  Ic + Id


Characteristics of displacement current:- 

                                                                                                          Characteristics of displacement current are follows:- 

1-  This current is equivalent to a magnetic field that           developed by variations in electric field.

2-  It can flow or pass in medium as well as free space.

3-  Free charges are not required for the displacement current.

4-  It is negligible in conducting materials but dominating in dielectric materials.

5- The displacement current in a good conductor is negligible compared to the conduction current at any frequency less than the optical frequencies .