2- Consider a right-circular solenoid of finite length L and radius a. Suppose that the sym- metry axis of the solenoid is the z-axis, and that it has N turns per unit length and carries a cur- rent I. Show that when the product NL → 0, the magnetic field B on the symmetry axis is 02 given by HỌNI (cos 01 + cos 02), where the angles are as indicated in the figure.

2- Consider a right-circular solenoid of finite length L and radius a. Suppose that the sym- metry axis of the solenoid is the z-axis, and that it has N turns per unit length and carries a cur- rent I. Show that when the product NL → 0, the magnetic field B on the symmetry axis is 02 given by HỌNI (cos 01 + cos 02), where the angles are as indicated in the figure.