Question

The anode plate in an experiment on photoelectric effect is kept vertically above the cathode plate. Light source is put on and a saturation photocurrent is recorded. An electric field is switched on which has vertically downward direction.

• A. no change in the photocurrent
• B. The kinetic energy of the electrons will increase
• C. The stopping potential will decrease
• D. The threshold wavelength will increase

Answer 1

The correct option is A no change in the photocurrent

In electric field photoelectrons will experience force and accelerate opposite to the field so its KE increases (ie, stopping potential will increase), no change in photoelectric current, and threshold wavelength.