when an electron is admitted from photosystem to it does not return the photosystem cannot trap any more light energy until the “hole” in the photosystem is filled with another electron the source of the electron that fills the “hole” in photosystem 2 is it NADPH

Answer 1

No, the source of the electron that fills the "hole" in photosystem 2 is water. Water is split during the light-dependent reactions of photosynthesis, releasing oxygen as a byproduct and providing electrons to replace those lost during photosystem 2's electron transport chain. NADPH is produced during the light-dependent reactions but is not the immediate source of electrons for photosystem 2.