question_answer

Monochromatic light of wavelengths 400 nm and 560 nm are incident simultaneously and normally on double slit apparatus whose slit separation is 0.1 mm and screen distance is 1 m. Distance between areas of total darkness will be

A)  \[4\text{ }mm\]            

B)  \[5.6\text{ }mm\]       

C)  \[28\text{ }mm\]          

D)  \[14\text{ }mm\]