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

$A$ 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:

Assertion : Standard optical diffraction gratings cannot be used for discriminating between $X-$ray wavelengths.
Reason : The grating spacing is not of the order of $X-$ray wavelengths.

Light of wavelength $6000 \ \mathring{A}$ is incident on a slit. The width of the slit is $0.30 \ mm$. A screen is placed at a distance of $2 \ m$ from the slit. Find the width of the central maximum in $mm$.

In a single-slit diffraction experiment,the first minimum for a wavelength $\lambda_1 = 660 \ nm$ coincides with the first maximum for a wavelength $\lambda_2$. Find the value of $\lambda_2$ in $nm$.

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