| Axial field of a finite, straight, thin shell solenoid |
| This formula uses the formula for the field due to a current loop, integrated over a range off axial displacements to obtain the magnetic field at any point on the axis of a finite, thin shell solenoid. | |
Solenoid in cross section view. |
|
| General Case: | |
 |
B
is the magnetic field, in teslas, at any point on the
axis of the solenoid. The direction of the field is
parallel to the solenoid axis.
i is the current in the wire, in amperes. N is the total number of turns of wire in the solenoid. l is the length of the solenoid, in meters. r is the radius of the solenoid, in meters. x1 and x2 are the distances, on axis, from the ends of the solenoid to the magnetic field measurement point, in meters. |
| Special Case: x1=(-x2) | |
|
The magnetic field measurement point is at the center of the solenoid. |
is the permeability constant (1.26x10-6
H/m)