 #1
Main Question or Discussion Point
Hi all I am confused with the inductor working, I want to understand it in very much detail. Pl see the following image,
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 setsup, 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
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 setsup, 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
Attachments

12.3 KB Views: 719