$A$ parallel beam of monochromatic light of wavelength $5000 \; \mathring{A}$ is incident normally on a single narrow slit of width $0.001 \; mm$. The light is focused by a convex lens on a screen placed on the focal plane. The first minimum will be formed for the angle of diffraction equal to ........$^o$.

$A$ 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 $\mathring{A}$?

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:

The box of a pinhole camera,of length $L$,has a hole of radius $a$. It is assumed that when the hole is illuminated by a parallel beam of light of wavelength $\lambda$,the spread of the spot (obtained on the opposite wall of the camera) is the sum of its geometrical spread and the spread due to diffraction. The spot would then have its minimum size (say $b_{min}$) when

The width of the central maximum of a diffraction pattern on a single slit does not depend upon:

$A$ screen is placed at a certain distance from a narrow slit,which is illuminated by a parallel beam of monochromatic light. What will you observe if you scan the screen with the help of a microscope?