(a) Identify electromagnetic waves which: (i) are used in radar system. (ii) affect a photographic plate. (iii) are used in surgery. Write their…

We consider, refracted wavefront CE and triangles ABC & AEC. From the triangles we obtained $$\sin \mathrm{i}=\frac{B C}{A C}=\frac{\mathrm{v}_{1} \tau}{A C} $$ $$\sin \mathrm{r}=\frac{A E}{A C}=\frac{\mathrm{v}_{2} \tau}{A C} $$ Thus $\displaystyle \frac{\sin i}{\sin r}=\frac{\mathbf{v}_{2}}{\mathbf{v}_{1}}$ We know $\displaystyle \mathrm{n}=\frac{c}{\mathrm{~V}}$, So $\displaystyle \frac{\sin \boldsymbol{i}}{\boldsymbol{\operatorname { s i n }} \boldsymbol{r}}=\frac{\boldsymbol{n}_{\mathbf{2}}}{\boldsymbol{n}_{\mathbf{1}}}$ which is the Snell's law.