Question

how cathode rays affect photographic plate

Answer 1

Answer:

Cathode rays are the invisible rays, emerging normally form the cathode of a discharge tube kept at a presence of (10-2 to 10-3 )mm Hg and under a very high potential difference of the order  (10-15) kV, supplied from an induction coil.

Explanation:

Cathode rays can produce x-rays

Cathode rays produce fluorescence

Cathode rays can produce physical and chemical changes