AC Generator working principle


1) AC generator is a device which is used to produce Alternating current from mechanical rotation.


2) AC generator was first invented by Nicola Tesla.


3) The name indicates that the generator produce an emf which is alternating that is it varies with time.


 

Generator Parts:

1) A rotating coil ABCD having N no of turns.

2) A magnetic field of strength B.

3) two slip rings

4) two carbon brushes.



Description:

1) the rotating coil ABCD is placed inside the magnetic field of strength B.

Suppose ABCD rectangular ring has area A.



2) And 

 is the angle made by the area vector with the magnetic field. Then magnetic flux passing through the rectangle is




3) Now the angle  can be expressed as   

Therefore







 

4) Now from Faraday’s law:

The induce emf in the coil is





        

 



5) Now when   then 





          


The maximum emf that can produce by the generator, So


( maximum value)

  

 

6) So, the alternating voltage is



        

Where




 

Drawing of  

 

as Sin function

 








 





 

So the graph is shown in below






  


 

Drawing of   



 emf in the form of time period

 


we know that


&


Then

  












 


So the graph is shown in below