Radio waves diffract around buildings,although light waves do not. The reason is that radio waves

In a single slit diffraction pattern:

$A$ light wave is incident normally on a slit of width $24 \times 10^{-5} \, cm$. The angular position of the second dark fringe from the central maximum is $30^\circ$. What is the wavelength of light in $\mathring{A}$?

When the distance between the slit and the screen is doubled,what happens to the angular separation between the fringes in a slit diffraction experiment?

$A$ single slit diffraction pattern is obtained using a beam of red light. If the red light is replaced by blue light, then:

The diffraction pattern of light of wavelength $400 \ nm$ diffracting from a slit of width $0.2 \ mm$ is focused on the focal plane of a convex lens of focal length $100 \ cm$. The width of the $1^{\text{st}}$ secondary maxima will be: