  We use the modified propagator for quantum field based on a ``principle of
path integral duality" proposed earlier in a paper by Padmanabhan to
investigate several results in QED. This procedure modifies the Feynman
propagator by the introduction of a fundamental length scale. We use this
modified propagator for the Dirac particles to evaluate the first order
radiative corrections in QED. We find that the extra factor of the modified
propagator acts like a regulator at the Planck scales thereby removing the
divergences that otherwise appear in the conventional radiative correction
calculations of QED. We find that:(i) all the three renormalisation factors
$Z_1$, $Z_2$, and $Z_3$ pick up finite corrections and (ii) the modified
propagator breaks the gauge invariance at a very small level of
${\mathcal{O}}(10^{-45})$. The implications of this result to generation of the
primordial seed magnetic fields are discussed.
