Friends hamse aksar pucha jata hai ki sir what is electromagnetic induction. To dear students aaj ham isi ke bare me baat karege ki electromagnetic induction kya hota hai. Iske bare me detail janege. 
Electromagnetic induction ka start Scientist Farady se hua. Sabse pahle electromagnetic induction ka khoj Faraday ne hi kya tha. Jab kisi coil se magnetic flux ka value lagataar change hota hai to us coil me ek electro-motive force utpann ho jata hai jise ham electromagnetic induction kahte hain. Jab kisi coli se magnetic flux lagataar change hota hai to usme ek voltage utpann ho jata hai aur jab ise ham kisi wire se connect karte hain to is se electric current bhi flow karta hai. Isi ghatna ko electromagnetic induction kha jata hai. 
Electromagnetic induction ke baare me sabse pahle Farady scientist ne khoj kiya tha. Unhone dekha ki jab kisi coil ke najdik kisi magnet ko motion karbate hai to is se coil se magnetic line of force ka number continuous change hota hai. Is karan magnetic flux bhi change hota hai. Aur is magnetic flux ke lagataar change hone ke karan us coil me ek electromotive force (voltage) utpann ho jata hai. Isi ghatna ko electromagnetic induction kahte hain.
Laws of electromagnetic induction

Condition of electromagnetic induction

Ab tak hamlog itna to jaan chuke hain ki electromagnetic induction me coil se magnetic flux change hone ke karan usme electromotive force utpann ho jata hai to electromagnetic induction ke lie yah ek sabse jaruri condition hai ki coil se magnetic flux continuous change hote rahna chahiea.
Magnetic flux continuous change hone ke lie 3 baat ho saktee hai. 
  • Sabse pahle ki agar coil se magnetic field ka value change hota hai to coil se magnetic flux bhi change ho jaaega is karan coil me voltage utpann ho jaaega. Magnetic field ka value change karne ke lie magnet ko coil ke najdeek relative motion karbana chahiea. 
  • Dusre tarike me magnetic flux change karne ke lie ham coil ka area change karte hai. Coil ka area change hone se bhi magnetic flux continuous change hota hai. Is karan bhi electr-magnetic induction ke karan coil me voltage utpann ho sakta hai.
  • Agar coil ko continuous rotate karaya jae to is karan se magnetic field aur area vector ke bich angle change hoga. Is karan magnetic flux change hoga uar electro-motive force utpann hoga.

Farady laws of electromagnetic induction

Aapko ab tak pata to chal ho gaya hoga ki  electromagnetic induction ka khoj Farady ne kiya tha. To farady ne is se related 2 laws bataya. Isi laws ko Faraday ka electromagnetic induction ka law kahte hain. 
(i) First law of electromagnetic induction
Electromagnetic induction ka first law yah kahta hai ki jab kisi coil se magnetic flux continuous change hota hai to us coil ke around ek electromotive force (voltage) utpann ho jata hai.
(ii) Second law of electromagnetic induction
Electromagnetic induction ka second law yah kahta hai ki kisi bhi coil se jab magnetic flux change hota hai to us coil me utpann hone bala emf flux ke rate change ke directly proportional hota hai.