Ray optics fails when

Light of wavelength $550\, nm$ falls normally on a slit of width $22.0 \times 10^{-5}\, cm$. The angular position of the second minima from the central maximum will be (in radians)

$A$ light wave of wavelength $\lambda$ is incident on a slit of width $d$. The resulting diffraction pattern is observed on a screen at a distance $D$. If the linear width of the principal maxima is equal to the width of the slit,then the distance $D$ is:

$A$ 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?

In a diffraction experiment from a single slit,the angular width of the central maximum does $NOT$ depend upon:

The position of the direct image obtained at $O$,when a monochromatic beam of light is passed through a plane transmission grating at normal incidence,is shown in the figure. The diffracted images $A, B$,and $C$ correspond to the first,second,and third-order diffraction. When the source is replaced by another source of shorter wavelength,then: