Question

12. Calculate the magnetic field inside
and outside of the long solenoid using
Ampere's circuital law.​

Answer 1

Answer:

Consider a solenoid of length L having N turns. The diametre of the solenoid is assumed to be much smaller when compared to its length and the coil is wound very closely. In order to calculate the magnetic field at any point inside the solenoid, we use Ampere’s circuital law. Consider a rectangular loop abed. Then from Ampere’s circuital law. Since the elemental lengths along be and da are perpendicular to the magnetic field which is along the axis of the solenoid, the integrals. where the length of the loop ab is h. But the choice of length of the loop ab is arbitrary. We can take very large loop such that it is equal to the length of the solenoid L. Therefore the integral is Let NI be the current passing through the solenoid of N turns, then The number of turns per unit length is given by NILNIL = nn then Since n is a constant for a given solenoid and μo is also constant. For a fixed current I, the magnetic field inside the solenoid is also a constant.