Let us assume the existence of magnetic charge related to the magnetic field by:
▽ * B = μ_o rho_m
a) Using the divergence theorem, obtain the magnetic Held of a point magnetic charge at the origin.

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?