  We report the results of mean field and the Monte Carlo study of the dynamic
magnetization-reversal transition in the Ising model, brought about by the
application of an external field pulse applied in opposition to the existing
order before the application of the pulse. The transition occurs at a
temperature T below the static critical temperature T_c without any external
field. The transition occurs when the system, perturbed by the external field
pulse competing with the existing order, jumps from one minimum of free energy
to the other after the withdrawal of the pulse. The parameters controlling the
transition are the strength h_p and the duration Delta t of the pulse. In the
mean field case, approximate analytical expression is obtained for the phase
boundary which agrees well with that obtained numerically in the small Delta t
and large T limit. The order parameter of the transition has been identified
and is observed to vary continuously near the transition. The order parameter
exponent beta was estimated both for the mean field (beta =1) and the Monte
Carlo beta = 0.90 \pm 0.02 in two dimension) cases. The transition shows a
"critical slowing-down" type behaviour near the phase boundary with diverging
relaxation time. The divergence was found to be logarithmic in the mean field
case and exponential in the Monte Carlo case. The finite size scaling technique
was employed to estimate the correlation length exponent nu (= 1.5 \pm 0.3 in
two dimension) in the Monte Carlo case.
