When light is incident on a diffraction grating,the zero-order principal maximum will be:

$A$ single slit diffraction pattern is obtained using a beam of red light. If the red light is replaced by blue light,then:

$A$ 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:

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 $D=$

$A$ monochromatic light of wavelength $6000 \text{ Å}$ is incident on a single slit of width $0.01 \text{ mm}$. If the diffraction pattern is formed at the focus of a convex lens of focal length $20 \text{ cm}$, the linear width of the central maximum is: (in $\text{ mm}$)

In the diffraction pattern of a single slit,the width of the secondary maxima compared to the central maximum is: