Question

For small angles Snell’s law becomes ______.

Options

• n₁i = n₂

• i = r

• n₁ = n₂r

• n₁i = n₂r

Answer 1

For small angles Snell’s law becomes n₁i = n₂r.

Explanation:

According to Snell's law, ${\displaystyle \frac{\sin \text{i}}{\sin \text{r}}=\frac{{\text{n}}_2}{{\text{n}}_1}}$

If angles are small, sin i ≈ i and sin r ≈ r,

Hence, ${\displaystyle \frac{\text{i}}{\text{r}}=\frac{{\text{n}}_2}{{\text{n}}_1}}$ or i n₁ = r n₂