(a)[2]
Distinguish between vector and scalar quantities.
(b)
At a distance $x$ from an isolated point charge $Q$, the electric field strength $E$ is described by the equation $E = \frac{Q}{x^2 b}$, with $b$ being a constant.
(b(i))[2]
Apply the definition of electric field strength to demonstrate that $E$ has SI base units of $\text{kg m A}^{-1}\text{s}^{-3}$.
(b(ii))[2]
Use the units for $E$ stated in (b)(i) to work out the SI base units of $b$.