For a prism of prism angle  $\theta ={60}^0$ , the refractive indices of the left half and right half are, respectively, $n_1$  and  $n_2$   $(n_2\ge n_1)$    as shown in figure. The angle of incidence i is chosen such that the incident light rays will have minimum deviation if  $n_1=n_2=n=1.5$ .For the case of unequal refractive indices  $n_1=n$  and  $n_2=n+\Delta n$  ,(where is $\Delta n$  <<< n ) the angle of emergence is $e=i+\Delta e$  . Which of the following statement(s) is (are) correct?