Solution :
$V= 0.7\;V$
$\therefore \large\frac{eV}{K_BT}=\large\frac{1.6 \times 10^{-19} \times 0.6}{8.6 \times 10^{-5} \times 1.6 \times 10^{-19} \times 300}$
$\qquad= 27.14 $
$I=5 \times 10^{-12}\bigg[e^{27.14}-1\bigg]$
$\quad= 5 \times 10^{-12} [6.07 \times 10^{11}-1]$
$\qquad= 3.305\;A$
$\Delta I= 3.035 -0.063$
$\qquad= 2.972\;A$
$\Delta V= 0.7 -0.6 =0.1\;V$
Dynamic resistance $= \large\frac{\Delta V}{\Delta I}= \frac{0.1\;V}{2.972\;A}$
$\qquad= 0.336 \Omega$