Question

dry air will support a maximum electric field strength of about 2.0x10⁸V/m. Above that value, the field creates enough ionization in the air to make the air a conductor. this allows a discharge or spark that reduces the field. what, then, is the maximum voltage between two parrallel conducting plates separated by 3.5cm of dry air?

Answer 1

The maximum voltage between these plates is

$$V=Ed=2·10^8·0.035=7·10^6\text{ V}.$$