The physical quantity having the dimensions of the square root of the ratio of the kinetic energy and surface tension is

If $\varepsilon_0$ and $\mu_0$ represent the permittivity and permeability of free space respectively,then the dimension of the product $\varepsilon_0 \mu_0$ is,

The dimensional formula of a physical quantity represented by $\frac{e^2}{4 \pi \varepsilon_0 \hbar}$ is (where $e$ is the charge of an electron,$\varepsilon_0$ is the permittivity of free space,and $\hbar$ is the reduced Planck's constant). Note: The expression $\frac{e^2}{4 \pi \varepsilon_0 \hbar}$ is equivalent to the fine-structure constant $\alpha$ multiplied by the speed of light $c$.

What is the dimensional formula of an electron volt $(eV)$, and what is its value in Joules $(J)$?

Dimensional formula for pressure head is

If $L$ and $R$ are respectively the inductance and resistance,then the dimensions of $\frac{L}{R}$ will be