question_answer

A ray of light is incident at polarising angle such that its deviation is \[{{24}^{o}}\], then angle of incidence is

A) \[{{24}^{o}}\]                                    

B) \[{{57}^{o}}\]

C) \[{{66}^{o}}\]                                    

D) \[{{90}^{o}}\]

Correct Answer: B

Solution :

Here\[{{i}_{p}}=r+\delta \]                 \[{{i}_{p}}=r+24\]                                             ... (i) Moreover           \[{{i}_{p}}+r={{90}^{o}}\]                             ... (ii) From Eqs. (i) and (ii), we get                 \[{{i}_{p}}({{i}_{p}}-{{24}^{o}})={{90}^{o}}\]                 \[{{i}_{p}}={{57}^{o}}\]