The dimension of electric current is

Two quantities $A$ and $B$ are related by the equation $A/B = m$,where $m$ is linear density and $A$ is force. The dimensions of $B$ are equivalent to which of the following?

The dimensional formula for angular momentum is

Dimensional formula for pressure head is

The dimension of Planck's constant is equal to that of:

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,