
Diagram above shows a ray of light moving from air toliquid A. Find the refractive index of the liquid A.
Answer:
Angle of incident, i = 90o - 30o = 60o
Angle of refraction, r = 45o
Refractive index,
\begin{gathered}
n = \frac{{\sin i}}
{{\sin r}} \hfill \\
n = \frac{{\sin 60^o }}
{{\sin 45^o }} = 1.22 \hfill \\
\end{gathered}