question_answer

A beam of monochromatic light is incident at \[i={{50}^{o}}\] on one face of an equilateral prism the angle of emergence is \[40{}^\circ ,\] then the angle of minimum deviation is-                   

A) \[{{30}^{o}}\]         

B) \[<{{30}^{o}}\]

C) \[\le {{30}^{o}}\]

D) \[\ge {{30}^{o}}\]