b
Energy, density, of, an ,electric, filed, E, is
\({u_E} = \frac{1}{2}{\varepsilon _o}{E^2}\)
Where,\({\varepsilon _o}\), is, permittivity, of, free, space
\({u_E} = \frac{{Energy}}{{Volume}} = \frac{{M{L^2}{T^{ - 2}}}}{{{L^3}}} = M{L^{ - 1}}{T^{ - 2}}\)
Hence, the, dim ension, of, \(\frac{1}{2}{\varepsilon _o}{E^2}\,is\,M{L^{ - 1}}{T^{ - 2}}\)