In the case of capacitance between the grid and other electrode(s) you have to view the grid as one plate of a capacitor, only the R component of the capacitor formed between the grid and other electrodes will dissipate any power, the R component of any capacitor formed between the grid and other electrode(s) is likely to be a low value...I think.
The capacitor formed between the grid to other electrode(s) is only one part of a capacitor in which current flows, the others parts being formed by external stray capacitances in the physical wiring of the circuit, valve socket etc.
EDIT: Altered bits to describe cga/cgk etc as a capacitor rather than capacitance so as to validate R.
Lawrence.
The capacitor formed between the grid to other electrode(s) is only one part of a capacitor in which current flows, the others parts being formed by external stray capacitances in the physical wiring of the circuit, valve socket etc.
EDIT: Altered bits to describe cga/cgk etc as a capacitor rather than capacitance so as to validate R.
Lawrence.
