Answer :
Answer:
The refractive index of the material is 1.28.
Explanation:
It is given that,
Refractive index of medium 1, n₁ = 1.31
Critical angle, [tex]\theta_c=78.3[/tex]
At critical angle rays will reflects at 90 degrees. Using Snell's law as:
[tex]n_1sin\theta_1=n_2sin\theta_2[/tex]
At critical angle, [tex]n_1sin\ \theta_c=n_2\ sin90[/tex]
[tex]n_1sin\ \theta_c=n_2[/tex]
[tex]n_2=1.31\times sin(78.3)[/tex]
[tex]n_2=1.28[/tex]
So, the refractive index of the material is 1.28. Hence, this is the required solution.