The radius $r$ of the $n^{th}$ half-period zone is proportional to:

Monochromatic light of wavelength $580 \,nm$ is incident on a slit of width $0.30 \,mm$. The screen is $2 \,m$ from the slit. The width of the central maximum is ........... $\times 10^{-3} \,m$.

$A$ screen is placed $0.5 \,m$ away from a single slit which is illuminated by a monochromatic light of wavelength $6000 \text{ Å}$. If the distance between the first and third minima in the diffraction pattern on the screen is $3 \,mm$, then the slit width is: (in $\,mm$)

In a single slit diffraction pattern,the distance between the plane of the slit and the screen is $1.3 \ m$. The width of the slit is $0.65 \ mm$ and the second maximum is formed at a distance of $2.6 \ mm$ from the center of the screen. The wavelength of light used is: (in $Å$)

Light of wavelength $\lambda$ is incident on a single slit of width $a$,and the distance between the slit and the screen is $D$. In the diffraction pattern,if the slit width is equal to the width of the central maximum,then $D=$

Light of wavelength $6000 \, \mathring{A}$ is incident on a single slit of width $0.3 \, mm$. The angular position of the first minima will be