How will the diffraction pattern change when yellow light is replaced by blue light? The fringes will be

$A$ single slit of width $a$ is illuminated by a monochromatic light of wavelength $600 \, nm$. The value of $a$ for which the first minimum appears at $\theta = 30^{\circ}$ on the screen will be ........... $\mu m$.

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

$A$ parallel beam of light of wavelength $\lambda$ is incident normally on a narrow slit. $A$ diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the second minimum of the diffraction pattern,the phase difference between the rays coming from the two edges of the slit is:

Due to which optical phenomenon do we not see the shadow of an opaque object clearly?