Problem $2$:

Using COMSOL Application:

A high$-$voltage is applied across a point$-$plane electrode air gap, with the point electrode at high potential and the plate electrode grounded, as shown in Fig. $2.$

For an air gap d$=8$mm$,$ compute and plot the electric potential and field distribution in the gap for and applied voltage of:

a$.V=15kV$

b$.V=25kV$

Which of the two voltages causes corona discharge at the tip of the top electrode? $($Assume the breakdown strength of air $E_0=3k\frac{V}{m}m).$

A $9090mm$ square acrylic plate of $2$ mm thickness is placed on the surface of the bottom electrode. Plot the field distribution in the gap. What is the maximum field intensity at the electrode tip for the applied voltage of $25$ kV $?$ Compare with the case without dielectric plate and discuss.

Fig. $2$ Point$-$plate electrode gap