--%>
Assignment Help - homework help

Define Lumen or SI unit of luminous flux

Lumen: lm: The derived SI unit of luminous flux, stated as the luminous flux produced by a uniform point source of 1 cd releasing its luminous energy over a solid angle of 1 sr; it therefore has units of cd sr.

   Related Questions in Physics

  • Q : Explain Stefan-Boltzmann law

    Stefan-Boltzmann law (Stefan, L. Boltzmann): The radiated power P (that is the rate of emission of electromagnetic energy) of a hot body is proportional to the radiating surface area, A, and the 4th power of the thermodynamic temperature, T. The const

    		•
  • Q : Define Universal constant of gravitation

    Universal constant of gravitation: G The constant of proportionality in the Newton’s law of universal gravitation and that plays a comparable role in Sir Einstein's general relativity. This is equivalent to the 6.672 x 10-1

    		•
  • Q : Define Faraday constant Faraday

    Faraday constant: F (M. Faraday): The electric charge fetched by one mole of electrons or singly-ionized ions. It is equivalent to the product result of the Avogadro constant and the absolute value of the charge on an electron; this i

    		•
  • Q : Explain Boyle's law Boyle's law (R.

    Boyle's law (R. Boyle; 1662); Mariotte's law (E. Mariotte; 1676) - The product result of the volume and pressure of an ideal gas at constant (steady) temperature is constant.

    		•
  • Q : What MeV in MeV photon signify What

    What does MeV in MeV photon signify? Briefly describe it.

    		•
  • Q : Define Joule-Thomson effect or

    Joule-Thomson effect: Joule-Kelvin effect (J.P. Joule, W. Thomson [later Lord Kelvin]): The change in temperature which takes place whenever a gas expands into an area of lower pressure.

    		•
  • Q : Define Stefan-Boltzmann constant

    Stefan-Boltzmann constant: sigma (Stefan, L. Boltzmann): The constant of proportionality exist in the Stefan-Boltzmann law. It is equivalent to 5.6697 x 10-8 W/m2/K4.

    		•
  • Q : Define Heat pumps Heat pumps move heat

    Heat pumps move heat from one place to another. They work similar to refrigeration. The movement of heat takes energy, either electrical energy as in the use of  vapor compression heat pumps or thermal energy as in the use of absorption heat pump

    		•
  • Q : Define Hubbles law Hubble's law (E.P.

    Hubble's law (E.P. Hubble; 1925): The relationship discovered between radial velocity and distance. The further away a galaxy is away from is, the quicker it is receding away from us. The constant of proportionality is the Hubble cons

    		•
  • Q : What do you mean by the term positron

    What do you mean by the term positron? Explain in short.

    		•