Red light is generally used to observe the diffraction pattern from a single slit. If blue light is used instead of red light,then the diffraction pattern:

$A$ parallel beam of fast-moving electrons is incident normally on a narrow slit. $A$ fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased,which of the following statements is correct?

The angular deviation of the $5^{th}$ order dark fringe is $12^{\circ}$ in a single slit experiment. If the width of the slit is $9 \mu m$, then the wavelength of the incident light is: (in $Å$)

$A$ parallel beam of monochromatic light of wavelength $5000 \mathring{A}$ is incident normally on a single narrow slit of width $0.001 \text{ mm}$. The light is focused by a convex lens on a screen placed on its focal plane. The first minima will be formed for the angle of diffraction of . . . . . . (degree).

For the visibility of a diffraction pattern of a wave of light,the size of the slit or obstacle should be

$A$ light ray of wavelength $\lambda$ is passing through a pinhole of diameter $D$ and the effect is observed on a screen placed at a distance $L$ from the pinhole. The approximations of geometrical optics are applicable, if