$A$ 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:

In the diffraction due to a single slit,the central fringe ...

Light of wavelength $589.3 \, nm$ is incident normally on a slit of width $0.1 \, mm$. What will be the angular width of the central diffraction maximum in degrees?

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

Assertion: $A$ coloured spectrum is seen when we look through a muslin cloth.
Reason: It is due to the diffraction of white light on passing through fine slits.

$A$ parallel beam of fast-moving electrons is incident normally on a narrow slit. $A$ fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased,which of the following statements is correct?