Glossary of Physics (L)

 
Laser: A device that produces coherent light by stimulated emission of radiation.
Latent heat of fusion: The quantity of heat required to convert one unit mass of a substance from solid to the liquid state at its melting point without any change in its temperature.
Latent heat of sublimation: The quantity of heat required to convert one unit mass of a substance from solid to gaseous state without any change in its temperature.
Latent heat of vaporization: The quantity of heat required to convert one unit mass of a substance from liquid to gaseous state at its boiling point without any change in its temperature.
Law of Conservation of Energy: Energy can neither be created nor destroyed, but can be transformed from one form to another.
Law of conservation of mass: Mass can neither be created nor destroyed in a chemical reaction.
Law of conservation of momentum: In the absence of external forces, the total momentum of a group of interacting objects remains constant.
Lenz's law: The induced current always flows in such a direction that it opposes the cause producing it.
Light-year: The distance traveled by light through empty space in one year, it is equal to 9.46 x 1012 km.
Longitudinal strain: The ratio of change in length of a body to its initial length.
Longitudinal wave: The particles of the medium oscillate in the direction of propagation of the wave.
Luminosity: The total amount of energy radiated each second from the surface of a source.
Lyman series: A group of lines in the ultraviolet region in the spectrum of hydrogen.