Light is incident normally on a diffraction grating through which the first order diffraction is seen at $32^\circ$. The second order diffraction will be seen at

In a single slit diffraction pattern:

In Fraunhofer diffraction by a single slit,the width of the slit is $0.01 \ cm$. If the wavelength of the light incident normally on the slit is $5000 \ \mathring{A}$,the angular distance of the second maxima from the midline of the central maxima is . . . . . . $\text{rad}$.

Light of wavelength $5000 \text{ Å}$ is incident normally on a slit. The first minimum of the diffraction pattern is observed to lie at a distance of $5 \text{ mm}$ from the central maximum on a screen placed at a distance of $2 \text{ m}$ from the slit. The width of the slit is: (in $\text{ cm}$)

In a diffraction pattern due to a single slit,the angular width of the central maxima becomes half when the wavelength of the light used is changed from $\lambda$ to $7000 Å$. Then the value of $\lambda$ is (in $Å$)

$A$ circular disc is placed in front of a narrow source. When the point of observation is $2 \, m$ from the disc,it covers the first $HPZ$. The intensity at this point is $I$. When the point of observation is $25 \, cm$ from the disc,the intensity will be: