To find the distance $d$ over which a signal can be seen clearly in foggy conditions, a railways engineer uses dimensional analysis and assumes that the distance depends on the mass density $\rho$ of the fog, intensity (power/area) $s$ of the light from the signal and its frequency $f$. The engineer finds that $d$ is proportional to $\frac{1}{n}$. Find the value of $n$.

Which two of the following five physical parameters have same dimensions? (i) energy density (ii) refractive index (iii) dielectric constant (iv) Young's modulus (v) magnetic field

Dimension of magnetic field in $M, L, T$ and $C$ (Coulomb) is given as:

A quantity $X$ is given by $X={ϵ}_{0}L\frac{\Delta V}{\Delta t}$ where ${ϵ}_0$ is the permittivity of free space, $\mathrm{L}$ is length, $\Delta V$ is the potential difference and $\Delta t$ is time interval. The dimensions of $X$ are the same as for