Abstract
We obtain the V-I characteristics of the type-II superconductors for thin film by numerically solving the time-dependent Ginzburg-Landau equation coupled with the Maxwell equation in the two-dimensional region. We observe a sequence of pulses in the time development of the measured voltage, leading to intense energy dissipation in superconductors. We show that these voltage pulses are related to the penetration and annihilation of vortices at the boundary and the annihilation of two merging vortices with opposite sign.