The relative permittivity of distilled water is 81. The velocity of light in it will be :
Question:

The relative permittivity of distilled water is 81. The velocity of light in it will be :

(Given $\mu_{\mathrm{r}}=1$ )

1. $4.33 \times 10^{7} \mathrm{~m} / \mathrm{s}$

2. $2.33 \times 10^{7} \mathrm{~m} / \mathrm{s}$

3. $3.33 \times 10^{7} \mathrm{~m} / \mathrm{s}$

4. $5.33 \times 10^{7} \mathrm{~m} / \mathrm{s}$

Correct Option: , 3

Solution:

$\mathrm{V}=\frac{\mathrm{c}}{\sqrt{\mu_{\mathrm{r}} \varepsilon_{\mathrm{r}}}}$

$=3.33 \times 10^{7} \mathrm{~m} / \mathrm{sec}$