In diffraction,all fringes have .....

The phenomenon of diffraction was discovered by ...... .

$A$ microwave of wavelength $2.0 \ cm$ falls normally on a slit of width $4.0 \ cm$. The angular spread of the central maxima of the diffraction pattern obtained on a screen $1.5 \ m$ away from the slit,will be: (in $^{\circ}$)

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:

$A$ diffraction pattern is formed by blue light. If the blue light is replaced by yellow light, then . . . . . . .

$A$ parallel beam of light of wavelength $\lambda$ is incident normally on a single slit of width $d$. Diffraction bands are obtained on a screen placed at a distance $D$ from the slit. The second dark band from the central bright band will be at a distance given by