Calculate the resolving power of astronomical telescope, assuming the diameter of the objective lens to be $6 \mathrm{cm}$ and wavelength of light used to be $540 \mathrm{mm}$.

A coherent parallel beam of microwaves of wavelength $\mathrm{\lambda }=0.5 \mathrm{mm}$  falls on Young's double slit apparatus. The separation between the slits is $1.00 \mathrm{mm}$. The intensity of microwaves in measured on a screen placed parallel to the plane of the slits at a distance of $1.0 \mathrm{m}$ from it, as shown in the figure, Fig. $17.60$

(a) The incident beam falls normally on the double slit apparatus. Find the $y$-coordinates of all the interference minima on the screen.