Question

If $\hat{i}$ denotes a unit vector along incident light ray, $\hat{r}$ a unit vector along refracted ray into a medium of refractive index $\mu$ and $\hat{n}$ unit vector normal to boundary of medium directed towards incident medium, then law of refraction is

• A. $\hat{i} \cdot \hat{n}=\mu(\hat{r} \cdot \hat{n})$
• B. $\hat{i} \times \hat{n}=\mu(\hat{n} \times \hat{r})$
• C. $\hat{i} \times \hat{n}=\mu(\hat{r} \times \hat{n})$
• D. $\mu(\hat{i} \times \hat{n})=\hat{r} \times \hat{n}$

Answer 1

Answer: (C)

Snell's law in vector form is $\hat{i} \times \hat{n}=\mu(\hat{r} \times \hat{n})$