Light of wavelength $\lambda$ is incident on a slit of width $d$. The resulting diffraction pattern is observed on a screen at a distance $D$. The linear width of the principal maximum is then equal to the width of the slit if $D$ equals

In diffraction,all fringes have .....

In a single-slit diffraction pattern,the intensity of the central maximum is $I_0$. If the slit width is doubled,what will be the intensity of the central maximum?

In the experiment of diffraction due to a single slit,if the slit width is decreased,the width of the central maximum

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

$A$ light wave is incident 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 the light in $\mathring{A}$?