$A$ Fraunhofer diffraction pattern due to a single slit of width $0.3 \text{ mm}$ is obtained on a screen placed at a distance of $3 \text{ m}$ from the slit. The first minima lie at $5.5 \text{ mm}$ on either side of the central maximum on the screen. The wavelength of light used is (in $\text{ Å}$)

In a single slit diffraction experiment,for a wavelength of light $\lambda$,the half-angular width of the central maxima is $\theta$. For a wavelength of light $p\lambda$,the half-angular width of the central maxima is $q\theta$. What is the ratio of the half-angular widths of the first secondary maxima in the first case to the second case?

$A$ parallel beam of monochromatic light of wavelength $5 \times 10^{-7} \ m$ is incident normally on a single narrow slit of width $10^{-3} \ mm$. At what angle of diffraction is the first minima observed?

$A$ microwave of wavelength $2.0 \ cm$ falls normally on a slit of width $4.0 \ cm$. The angular spread of the central maxima of the diffraction pattern obtained on a screen $1.5 \ m$ away from the slit,will be: (in $^{\circ}$)

Due to which optical phenomenon do we not see the shadow of an opaque object clearly?

$A$ diffraction pattern is obtained by using a beam of red light. What will happen if the red light is replaced by blue light?