question_answer

A glass plate 0.40 micron thick is illuminated by a beam of white light normal to the plate. The refractive index of glass is 1.50 and the limits of the visible spectrum are \[{{\lambda }_{V}}=4000\,\overset{o}{\mathop{A}}\,\] and\[{{\lambda }_{R}}=7000\,\overset{o}{\mathop{A}}\,\] The wavelengths that get intensified in the reflected beam are

A) \[\text{4800 }\overset{o}{\mathop{A}}\,\]and \[5200\overset{o}{\mathop{A}}\,\]  

B) \[4800\overset{o}{\mathop{A}}\,\]and \[6700\overset{o}{\mathop{A}}\,\]

C) \[4800\overset{o}{\mathop{A}}\,\]only  

D) \[5200\overset{o}{\mathop{A}}\,\]only