The experimentally obtained (Venkataraman {\em et al}. \cite{latha}) cosine
squared relation of electronic conductance in a biphenyl molecule is verified
theoretically within a tight-binding framework. Using Green's function
formalism we numerically calculate two-terminal conductance as a function of
relative twist angle among the molecular rings and find that the results are in
good agreement with the experimental observation.Comment: 3 pages, 3 figure