What is the definition of the photoelectric effect?
The photoelectric effect is the emission of electrons from the surface of a metal due to exposure of electromagnetic radiation above a certain frequency.
Photon energy (E=hf or E=hc/λ).
The work function is the minimum energy needed by a conduction electron to escape from the metal surface when the metal is at zero potential.
When a conduction electron absorbs a photon, its kinetic energy increases by an amount equal to the energy of the photon. If the energy of the photon exceeds the work function, the conduction electron can leave the metal.
If the conduction electron doesn’t leave the metal, it repeatedly collides with other electrons and positive ions and loses its extra kinetic energy
CD
Related Physics A Level answers
All answers ▸One of the decays of potassium (A=40, Z=19) results in an excited argon atom with excess energy of 1.50 Mev. In order to be stable, it emits a gamma photon. What frequency and wavelength has this gamma photon?
A uniform plank of wood of mass 32 kg and length 4.0 m is used to cross a ditch. In the ditch is a rock, which is used to support the plank horizontally 0.80 m from one end. The other end is supported by the bank. Calculate the rock's supporting force.
A ball of mass 0.7 kg strikes the wall at an angle of 90 degrees with speed 72 km/h. Consider that the bounce lasts for 0.1 s and is perfectly elastic. What is the magnitude of the average reaction force from the wall that acts on the ball?
The LHC accelerates protons to a speed of 0.999999991c around a 27km ring. Due to relativistic effects, their mass increases. Given that the magnetic fields used are 8T, calculate this mass. What is the total energy of an LHC beam containing 3e14 protons?