A single slit of width a is illuminated by violet light of wavelength 400 nm and the width of the diffraction pattern is measured as y. When half of the slit width is covered and illuminated by yellow light of wavelength 600 nm, the width of the diffraction pattern is

Options

A. the pattern vanishes and the width is zero
B. `y//3`
C. 3y
D. none of these

Answer

c

Explanation

In single slit experiment
width of central maxima `(y) = 2lambdaD//d`
where `lambda` = wavelength of source used
D-distance between slit and screen
d = width of slit.