The diffraction effect can be observed in

Obtain the formulas for the angular width and linear width of the central maximum in a single-slit diffraction experiment.

Light of wavelength $\lambda = 5000 \ \mathring{A}$ falls normally on a narrow slit. $A$ screen is placed at a distance of $1 \ m$ from the slit and perpendicular to the direction of light. The first minima of the diffraction pattern is situated at $5 \ mm$ from the centre of the central maximum. The width of the slit is ....... $mm$.

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

The waves of $600 \ \mu m$ wavelength are incident normally on a slit of $1.2 \ mm$ width. The value of diffraction angle corresponding to the first minima will be (in radian) -

In a single slit diffraction,the slit is illuminated with light of wavelength $6000 \text{ Å}$. If the slit were illuminated by a light of wavelength $\lambda$ the angular width of the central maximum decreases by $30 \%$. Then $\lambda$ is (in $\text{ Å}$)