Understanding the Photoelectric Effect

What is the purpose of scrubbing the zinc plate with iron wool in the photoelectric effect demonstration?

• To make the plate shiny

• To cool down the plate

• To remove the surface oxide layer

• To charge the plate positively

How is the zinc plate charged negatively in the demonstration?

• By exposing it to visible light

• By using the method of charging by induction

• By connecting it to a battery

• By rubbing it with a cloth

What happens when visible light is shone on the negatively charged zinc plate?

• The gold leaf falls

• The plate becomes positively charged

• Nothing happens

• The plate emits light

Why does ultraviolet light cause the gold leaf to fall in the demonstration?

• It charges the plate positively

• It changes the plate's color

• It releases electrons from the plate

• It heats the plate

What was Albert Einstein's contribution to the understanding of the photoelectric effect?

• He proved light is only a wave

• He invented the electroscope

• He discovered ultraviolet light

• He explained the phenomenon using the concept of photons