  The charged current lepton production induced by neutrinos in $^{56}Fe$
nuclei has been studied. The calculations have been done for the quasielastic
as well as the inelastic reactions assuming $\Delta$ dominance and take into
account the effect of Pauli blocking, Fermi motion and the renormalization of
weak transition strengths in the nuclear medium. The quasielastic production
cross section for lepton production are found to be strongly reduced due to
nuclear effects while there is about 10% reduction in the inelastic cross
sections in the absence of the final state interactions of the pions. The
numerical results for the momentum and angular distributions of the leptons
averaged over the various atmospheric neutrino spectra at the Soudan and
Gransasso sites have been presented. The effect of nuclear model dependence and
the atmospheric flux dependence on the relative yield of ${\mu}$ to e has been
studied and discussed.
