Question

In the Photoelectric setup, I would like to achieve stopping potential by making one of the plates in the setup, positively charged. Which one should I charge positively?

• A. The collector plate
• B. The emitter plate
• C. Stopping potential cannot be achieved by making any plate positively charged
• D. More data is required to make a selection

Answer 1

The correct option is B

The emitter plate

In the diagram, light is falling on the left, which is the emitter plate, and the photoelectrons would be collected by the plate on the right, the collector plate. Electrons being negatively charged, will be repelled and slowed down if the collector plate is made negative. or if the emitter plate itself is made positive, electrons coming out will be attracted back to the left, and could, possibly, never make it to the collector plate - thus achieving stopping potential. Hence, (b) is correct.