Which pair has the same dimensions?

$\left[ML^2 T^{-2} K^{-1}\right]$ is the dimensional formula of which physical quantity?

Which of the following quantities is dimensionless?

The dimensional formula of heat energy is:

If $C$ and $R$ represent capacitance and resistance respectively,then the dimensions of $RC$ are

$A$ temperature difference can generate $e.m.f.$ in some materials. Let $S$ be the $e.m.f.$ produced per unit temperature difference between the ends of a wire,$\sigma$ the electrical conductivity and $\kappa$ the thermal conductivity of the material of the wire. Taking $\text{M, L, T, I}$ and $K$ as dimensions of mass,length,time,current and temperature,respectively,the dimensional formula of the quantity $Z=\frac{S^2 \sigma}{\kappa}$ is :-