a
(a) \([e] = [AT],\)\({ \in _0} = [{M^{ - 1}}{L^{ - 3}}{T^4}{A^2}],\) \([h] = [M{L^2}{T^{ - 1}}]\)
and \([c] = [L{T^{ - 1}}]\)

\(\therefore \)\(\left[ {\frac{{{e^2}}}{{4\pi { \in _0}hc}}} \right] = \left[ {\frac{{{A^2}{T^2}}}{{{M^{ - 1}}{L^{ - 3}}{T^4}{A^2} \times M{L^2}{T^{ - 1}} \times L{T^{ - 1}}}}} \right]\)

\( = [{M^0}{L^0}{T^0}]\)