If $\varepsilon_{0}$ and $\mu_{0}$ represent the permittivity and permeability of vaccum and $\varepsilon$ and $\mu$ represent the permittivity and permeability of medium, then refractive index of the medium is given by

• A

  $\sqrt{\frac{\varepsilon_{0} \mu_{0}}{\varepsilon \mu}}$
• Correct answer
  B

  $\sqrt{\frac{\varepsilon \mu}{\varepsilon_{0} \mu_{0}}}$
• C

  $\sqrt{\frac{\mu_{0} \varepsilon_{0}}{\varepsilon}}$
• D

  $\sqrt{\frac{\mu_{0} \varepsilon_{0}}{\mu}}$

Hence, the correct answer is option: 'B'.