--%>
Assignment Help - homework help

Explain Photoelectric effect

Photoelectric effect: An effect described by A. Einstein that demonstrates that light seems to be made up of particles, or photons. The light can excite electrons (termed as photoelectrons in this context) to be ejected from the metal. Light with a frequency below with a certain threshold, at any intensity, will not origin any photoelectrons to be emitted from metal. Above the frequency, photoelectrons are emitted in proportion to the intensity of the incident light.

The reason is that a photon comprises energy in proportion to its wavelength, and constant of proportionality is the Planck’s constant. Below a certain frequency -- and therefore below a certain energy -- the incident photons do not contain enough energy to knock the photoelectrons out of the metal. Over that threshold energy, termed as the work function, the photons will bang the photoelectrons out of the metal, in proportion to the number of photons (that is the intensity of the light). In higher energies and frequencies, the photoelectrons ejected get a kinetic energy equivalent to the difference among the photon's energy and the work function.

   Related Questions in Physics

  • Q : What is Maxwells demon Maxwell's demon

    Maxwell's demon (J.C. Maxwell): A contemplation experiment describing the concepts of entropy. We contain a container of gas that is partitioned into two equivalent sides; each side is in thermal equilibrium with the other. The walls and the separatio

    		•
  • Q : Concept of nuclear reaction Describe in

    Describe in brief the concept of nuclear reaction?

    		•
  • Q : Define Planck constant Planck constant

    Planck constant: h: The basic constant equivalent to the ratio of the energy of a quantum of energy to its frequency. This is the quantum of action. This has the value 6.626 196 x 10-34 J s.

    		•
  • Q : Problem on multiplexed channels 4

    4 channels, two with a bit-rate of 200 kbps and two with a bit-rate of 150 Kbps are to be multiplexed employing multiple slots TDM with no sync bits. a. Find out the size of a frame in bits?

    Q : What is Cherenkov radiation Cherenkov

    Cherenkov radiation (P.A. Cherenkov): The radiation emitted by a huge particle which is moving faster than light in the medium via which it is travelling. No particle can travel faster than the light in vacuum, however the speed of light in other medi

    		•
  • Q : What is Paschen series Paschen series:

    Paschen series: The series that explains the emission spectrum of hydrogen whenever the electron is jumping to the third orbital. Each and every line is in the infrared part of the spectrum.

    		•
  • Q : Define Atwood's machine Atwood's

    Atwood's machine: The weight-and-pulley system devised to compute the acceleration due to gravity at Earth's surface by computing the total acceleration of a set of weights of identified mass about a frictionless pulley.

    		•
  • Q : What is Bernoulli's equation

    Bernoulli's equation - In an ir-rotational fluid, the sum of static pressure, the weight of the fluid per unit mass times the height and half of the density times the velocity squared is steady all through the fluid 

    		•
  • Q : Weak equivalence or principle of

    Weak equivalence principle: principle of uniqueness of freefall: The idea in general relativity is that the world-line of a freefalling body is sovereign of its composition, structure, or state. This principle, hold by Newtonian mechanics and gravitat

    		•
  • Q : State Kohlrauschs law Kohlrausch's law

    Kohlrausch's law (F. Kohlrausch): When a salt is dissolved in water, the conductivity of the solution is the addition of two values -- one depending on the positive ions and the other on negative ions.

    		•