Monochromatic light is incident on a metal surface in a vacuum, causing photoelectrons to be emitted. The photoelectric current III is the rate of flow of charge from the surface. The maximum kinetic energy of the photoelectrons is Ek(max)E_{k(\text{max})}Ek(max). The wavelength of the incident light is then increased, whilst keeping the total power incident on the metal surface constant. The frequency of the light remains above the threshold frequency of the metal. What happens to Ek(max)E_{k(\text{max})}Ek(max) and III when the wavelength is increased?
Ek(max)E_{k(\text{max})}Ek(max): increases; III: decreases
Ek(max)E_{k(\text{max})}Ek(max): increases; III: increases
Ek(max)E_{k(\text{max})}Ek(max): decreases; III: increases
Ek(max)E_{k(\text{max})}Ek(max): decreases; III: decreases
31 exam-style questions on AQA A Level Physics Electromagnetic radiation and quantum phenomena, covering The photoelectric effect, Collisions of electrons with atoms, Energy levels and photon emission, and Wave-particle duality. Each one has a worked solution and a mark scheme showing where the marks go.