Question

Light is an electromagnetic wave. Its speed in vacuum is given by the expression

• A. $\sqrt{{\mu }_0{e}_0}$
• B. $\sqrt{\frac{{\mu }_0}{e_0}}$
• C. $\sqrt{\frac{e_0}{{\mu }_0}}$
• D. $\frac{1}{\sqrt{{\mu }_0{e}_0}}$

Answer 1

The correct option is D

$\frac{1}{\sqrt{{\mu }_0{e}_0}}$

${\mu }_0=4\pi \times {10}^{-7},{ϵ}_0=8.85\times {10}^{-12}\frac{N-m^2}{C^2}$

so $c=\frac{1}{\sqrt{{\mu }_0{e}_0}}=3\times {10}^8\frac{meter}{sec}.$