- #1

AASHISH SRIVASTAVA

- 9

- 3

Hi all I am confused with the inductor working, I want to understand it in very much detail. Pl see the following image,

Now in fig 2 let the switch is closed at t=0, current flows and a magnetic field sets-up, this magnetic field produces back emf and so current stops at t=0+ and the inductor behaves as open circuit

the texts say that inductor doesn't allow sudden change of current, OK, then if the inductor was uncharged its i(0-) = 0 and so i(0) = i(0+) = 0 so how the magnetic field sets -up ? and how the back emf produced ? and who stopped the current ?

and texts say at t=0 voltage across inductor (back emf) will be V but from equation V(inductor) = L(di/dt) now if there was back emf, there must be flux change so there must be a sudden current change so di/dt = infinity so V(inductor) = infinity not V

I am deeply confused

Pls help me

thanks in advance

**First Thing :**Here we have an initially uncharged inductor L in fig 1 with a switch S and a const. voltage source of voltage V.Now in fig 2 let the switch is closed at t=0, current flows and a magnetic field sets-up, this magnetic field produces back emf and so current stops at t=0+ and the inductor behaves as open circuit

**NOW THE CONFUSIONS**

the texts say that inductor doesn't allow sudden change of current, OK, then if the inductor was uncharged its i(0-) = 0 and so i(0) = i(0+) = 0 so how the magnetic field sets -up ? and how the back emf produced ? and who stopped the current ?

and texts say at t=0 voltage across inductor (back emf) will be V but from equation V(inductor) = L(di/dt) now if there was back emf, there must be flux change so there must be a sudden current change so di/dt = infinity so V(inductor) = infinity not V

I am deeply confused

Pls help me

thanks in advance