question_answer

A plane glass slab is kept over various coloured letters, the letter which appears least raised is [J & K CET 2004; BHU 1998, 05]

A)            Blue                                         

B)            Violet

C)            Green                                     

D)            Red

Correct Answer: D

Solution :

                   \[\mu =\frac{h}{{{h}'}}\Rightarrow {h}'\propto \frac{1}{\mu }\]                      \[\because {{\mu }_{R}}<{{\mu }_{V}}\] so \[{{{h}'}_{R}}>{{{h}'}_{V}}\]                 i.e. Red colour letter appears least raised.