can the electrodes of electron tubes also be thought of as capacitors charged by light or photons striking on them?

See the previous nearby euroelectron posts. The input impedance of the voltmeter used is greater than 1GΩ.


What would happen if after the capacitance is charged by a light torch in a darkened room and then a heater voltage is applied?


See:


http://euroelectron.blogspot.gr/2018/05/why-are-ther-potential-differences.html


Can the electrodes be thought as capacitors being charged by light (photoelectric effect) or heat (thermionic emission). The potential difference or self bias on 2 electrodes depends on both stimuli. Cathode to grid self assumed voltage has not yet been examined under darkened room conditions).