Question

The refractive index of water is 1.33. What will be the speed of light in water?

• A. $3 \times 1 0^{8 \, } \text{ms}^{- 1}$
• B. $4 \times 1 0^{8 \, } \text{ms}^{- 1}$
• C. $1.33 \times 1 0^{8 \, } \text{ms}^{- 1}$
• D. $2.26 \times 1 0^{8 \, } \text{ms}^{- 1}$

Answer 1

Answer: (D)

We know that refractive index of a medium is given by :
$\mu = \frac{c}{ v }$
$\therefore v = \frac{c}{\mu } = \frac{3 \times 1 0^{8}}{1 \cdot 3 3} = 2.26 \times 1 0^{8 \, } \text{ms}^{- 1}$