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Photomagnetism ( photomagnetic effect) is the effect in which a material acquires (and in some cases loses) its ferromagnetic properties in response to light. The current model for this phenomenon is a light-induced electron transfer, accompanied by the reversal of the spin direction of an electron.
Photomechanical effect. Photomechanical effect is the change in the shape of a material when it is exposed to light. This effect was first documented by Alexander Graham Bell in 1880. [1] More recently, Kenji Uchino demonstrated that a photostrictive material could be used for legs in the construction of a miniature optically-powered "walker".
Counter-electromotive force. Counter-electromotive force ( counter EMF, CEMF, back EMF ), [1] is the electromotive force (EMF) manifesting as a voltage that opposes the change in current which induced it. CEMF is the EMF caused by electromagnetic induction .
Attenuation. In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates.
Photoacoustic effect. The photoacoustic effect or optoacoustic effect is the formation of sound waves following light absorption in a material sample. In order to obtain this effect the light intensity must vary, either periodically ( modulated light) or as a single flash ( pulsed light ). [1] [page needed] [2] The photoacoustic effect is ...
In a typical amorphous silicon solar cell the efficiency is reduced by up to 30% in the first 6 months as a result of the Staebler–Wronski effect, and the fill factor falls from over 0.7 to about 0.6. This light induced degradation is the major disadvantage of amorphous silicon as a photovoltaic material. Methods of reducing the SWE
Photoelasticity. Plastic utensils in a photoelasticity experiment. In materials science, photoelasticity describes changes in the optical properties of a material under mechanical deformation. It is a property of all dielectric media and is often used to experimentally determine the stress distribution in a material.
Definition. Lenz's law states that: The current induced in a circuit due to a change in a magnetic field is directed to oppose the change in flux and to exert a mechanical force which opposes the motion. Lenz's law is contained in the rigorous treatment of Faraday's law of induction (the magnitude of EMF induced in a coil is proportional to the ...