(a) Write three characteristic features to distinguish between the interference fringes in Young’s double slit experiment and the diffraction pattern obtained due to a narrow single slit.
(b) 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 distance of 2.5 mm away from the centre. Find the width of the slit.
