$A$ slit of width $a$ is illuminated by red light of wavelength $6500 Å$. If the first diffraction minimum falls at $30^{\circ}$,then the value of $a$ is

If $\lambda = 6000 \, \mathring{A}$ and $a = 18 \times 10^{-5} \, \text{cm}$,find the angular width of the central maximum in degrees $(^\circ)$.

Consider the diffraction pattern obtained from the sunlight incident on a pinhole of diameter $0.1 \, \mu m$. If the diameter of the pinhole is slightly increased,it will affect the diffraction pattern such that :

The diffraction fringes obtained by a single slit are of

The phenomenon of diffraction of light was discovered by

In a single slit diffraction experiment, a parallel beam of green light of wavelength $\lambda = 550 \,nm$ passes through a slit of width $a = 0.20 \,mm$. The transmitted light is collected on a screen at a distance $D = 100 \,cm$ away. The distance of the first-order minima from the central maximum is $x \times 10^{-5} \,m$. The value of $x$ is: