  We study dielectric breakdown in a semi-classical bond percolation model for
nonlinear composite materials introduced by us and the related breakdown
exponent near the percolation threshold in two dimensions. The breakdown
exponent after doing finite size scaling analysis is found to be $t_B \simeq$
1.42. We discuss in detail the differences in our model from the traditional
models for dielectric breakdown and argue that our result seems to be different
from the standard result of 4/3 obtained in the previous models.
