Let I = current through a conductor, R = its resistance and V =

potential difference across its ends. According to Ohm’s law, product

of two of these quantities equals the third. Obtain Ohm’s law from

dimensional analysis. Dimensional formulae for R and V are ML^{2}I^{-2}T^{3}

and ML^{2} T^{-3} I^{-1} respectively.