What is the photoelectric effect?
The photoelectic effect is when photoelectrons are released from a metal that light is incident upon. The photoelectrons are only emitted when the photons of light are above a certain threshold frequency and energy (called the work function). The energy of the photoelectrons is equivalent to the gaps in electron energy levels of the atoms that compose the metal. Each photon above the work function produces exactly 1 photoelectron and any excess energy is given to the photoelectron in the form of kinetic energy. If the frequency of the light is below the threshold frequency then no photoelectrons are released.
GR
Related Physics A Level answers
All answers ▸Name the four fundamental forces.
A 10m long uniform beam is pivoted in its centre. A 30kg point mass is placed on one end of the beam. Where must a 50kg mass be placed in order to balance the beam?
A circuit with a voltage source of 18V, has 3 resistors all connected on parallel, values at 2ohms, 6ohms and 7.5ohms. Find the total circuit resistance, and then subsequently, the total current supplied and power dissipated in the curcuit.
What is the difference between a scalar and a vector quantity?