An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is
$c{\left( {2mE} \right)^{{1 \over 2}}}$
${1 \over c}{\left( {{{2m} \over E}} \right)^{{1 \over 2}}}$
${1 \over c}{\left( {{E \over {2m}}} \right)^{{1 \over 2}}}$
${\left( {{E \over {2m}}} \right)^{{1 \over 2}}}$
