question_answer

Formula for dispersive power is (where symbols have their usual meanings)                       [MP PMT/PET 1988] or If the refractive indices of crown glass for red, yellow and violet colours are respectively \[{{\mu }_{r\,}},\,\,{{\mu }_{y}}\] and \[{{\mu }_{v}}\], then the dispersive power of this glass would be   [MP PMT 1996]

A)            \[\frac{{{\mu }_{v}}-{{\mu }_{y}}}{{{\mu }_{r}}-1}\]             

B)            \[\frac{{{\mu }_{v}}-{{\mu }_{r}}}{{{\mu }_{y}}-1}\]

C)            \[\frac{{{\mu }_{v}}-{{\mu }_{y}}}{{{\mu }_{y}}-{{\mu }_{r}}}\]       

D)  \[\frac{{{\mu }_{v}}-{{\mu }_{r}}}{{{\mu }_{y}}}-1\]