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

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

$A$ slit of size $0.15 \,cm$ is placed at $2.1 \,m$ from a screen. On illuminating it by a light of wavelength $5 \times 10^{-5} \,cm$,the width of the central maxima will be:

Light of wavelength $\lambda$ is incident on a slit of width $a$. The resulting diffraction pattern is observed on a screen placed at a distance $D$. If the linear width of the central maximum is equal to the width of the slit,then $D = $ . . . . . . .

Light of wavelength $\lambda$ is incident on a single slit of width $a$ and the distance between the slit and the screen is $D$. In the diffraction pattern, if the slit width is equal to the width of the central maximum, then $D$ is equal to:

$A$ parallel beam of light of wavelength $500\; nm$ falls on a narrow slit and the resulting diffraction pattern is observed on a screen $1\;m$ away. It is observed that the first minimum is at a distance of $2.5\;mm$ from the centre of the screen. Find the width of the slit. (in $; mm$)