Question

A beam of light of wavelength 600nm from a distance source falls on a single slit 1mm wide and a resulting diffraction pattern is observed on a screen 2m away. The distance between the first dark frings on either side of central bright fringe is
A. 1.2cm
B. 1.2mm
C. 2.4cm
D. 2.4mm

Answer 1

Correct Answer - d.
The distance between the first dark frigne on either side of the central bright fringe `=` width of central maximum `=(2Dlambda)/(a)`
`=(2xx2xx600xx10^(-9))/(10^(-3))=2.4xx10^(-3)m=2.4mm.`
(d) is the correct option.