Problem 3.213

A gas is ionized in the immediate vicinity of the surface of plane electrode 1 (Fig. 3.58 ) separated from electrode 2 by a distance \(l .\) An alternating voltage varying with time \(t\) as \(V=V_{0} \sin \omega t\) is applied to the electrodes. On decreasing the frequency \(\omega\) it was observed that the galvanometer \(G\) indicates a current only at \(\omega<\omega_{0}\), where \(\omega_{0}\) is a certain cut-off frequency. Find the mobility of ions reaching electrode 2 under these conditions.