Question

The distance between the electrodes is 2.6 cm. If the dielectric strength of the dry air between is 3 x 10^6 V/m, what is the voltage across the electrodes when the arc first forms?

Answer 1

Voltage across electrode

$V=E\times l$

$$V=3\times10^{6}\times0.026=0.078\times10^6V$$