question_answer

In a young double slit experiment, an interference pattern is obtained for\[\lambda =6000\overset{o}{\mathop{A}}\,\], coming from two coherent sources \[{{S}_{1}}\] and \[{{S}_{2}}\] at certain point P on the screen third fringe of dark is obtained. The n path difference \[{{S}_{1}}P-{{S}_{2}}P\]in microns is:

A) 1.5                   

B) 4.5    

C) 0.75                 

D) 3