# 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^2I^-2T^-3 and ML^2T^-3I^-1 respectively.

Given

Dimensional formula of R = [ML2T-3I-2]

Dimensional formula of V = [ML2T-3I-1]

Dimensional formula of I = [I]

Hence,

[ML2T-3I-1] = [ML2T-3I-2] [I]

V = IR