All Problems

Molecules and Crystals

Problem 6.205

The increase in temperature of a cathode in electronic tube by \(\Delta T=1.0 \mathrm{~K}\) from the value \(T=2000 \mathrm{~K}\) results in the increase of saturation current by \(\eta=1.4 \%\). Find the work function of electron for the material of the cathode.

Reveal Answer
A=kT(ηT/ΔT2)=4.5eVA=k T(\eta T / \Delta T-2)=4.5 \mathrm{eV}