Question

Dimensions of $\frac{1}{{\mu }_o{ϵ}_o}$, where symbols have their usual meaning, are

• A. $\left[L^{-1}T\right]$
• B. $\left[L^{-2}{T}^2\right]$
• C. $\left[L^2{T}^{-2}\right]$
• D. $\left[L{T}^{-1}\right]$

Answer 1

Answer: (C)

$\left[L^2{T}^{-2}\right]$

We have:

$c=\frac{1}{\sqrt{{\mu }_o{ϵ}_o}}$
$c^2=\frac{1}{{\mu }_o{ϵ}_o}$
$c=m/s=L{T}^{-1}$
$\Rightarrow c^2=L^2{T}^{-2}$