Question:
The relative permittivity of distilled water is 81. The velocity of light in it will be :
(Given $\mu_{\mathrm{r}}=1$ )
Correct Option: , 3
Solution:
$\mathrm{V}=\frac{\mathrm{c}}{\sqrt{\mu_{\mathrm{r}} \varepsilon_{\mathrm{r}}}}$
$=3.33 \times 10^{7} \mathrm{~m} / \mathrm{sec}$