Consider a long solenoid of radius a, length 1 and winding number N with tight winding. The magnetic field at the center
Posted: Thu Jul 07, 2022 2:05 pm
Consider a long solenoid of radius a, length 1 and winding number N with tight winding. The magnetic field at the center can be taken to be homogeneous inside with magni- S tude B (t) = μo1(t), where I (t) the current in the solenoid. N | a) Assume the solenoid is turned of at t = 0 and the current goes down as I(t) = Ige-¹/¹ Compute the induced electric field Eind(t). In which direction does it point compared to the current in the wire? b) Derive the characteristic time 7 in terms of the resistance R of the wire and the inductance L = πа² μN²/1 (note that the time-dependence drops out). Why is the turn-off process visible for a solenoid, but not for normal circuits?