--%>

Define Fermats principle

Fermat's principle: principle of least time (P. de Fermat): The principle, put onward by P. de Fermat that explains the path taken by a ray of light among any two points in a system is for all time the path which takes the least time.

   Related Questions in Physics

  • Q : Define Zeeman Effect or Zeeman line

    Zeeman Effect: Zeeman line splitting (P. Zeeman; 1896): Zeeman Effect is the splitting of lines in a spectrum whenever the source is exposed to the magnetic field.

  • Q : Define Kirkwood gaps Kirkwood gaps

    Kirkwood gaps (Kirkwood): The gaps in the asteroid belt, caused by the resonance effects from Jupiter. Similar gaps are also exists in Saturn's rings, due to the resonance effects of the shepherd moons.

  • Q : Rest mass energy of the electron What

    What do you mean by the rest mass energy of the electron?

  • Q : Explain Kirchhoffs laws or Kirchhoffs

    Kirchhoff's laws (G.R. Kirchhoff) Kirchhoff's first laws: An incandescent solid or gas in high pressure will generate a continuous spectrum.

    Q : What is Reflection law Reflection law :

    Reflection law: For a wave-front intersecting a reflecting surface, the angle of incidence is equivalent to the angle of reflection, in the similar plane stated by the ray of incidence and the normal.

  • Q : What is Universal age paradox Universal

    Universal age paradox: The two most straightforward techniques of computing the age of the Universe -- via red-shift measurements, and via stellar evolution -- outcome incompatible outcomes. Recent (in mid 1990s) measurements of the distances of far-a

  • Q : Define Rayleigh criterion or resolving

    Rayleigh criterion: resolving power: The criterion for determining how delicately a set of optics might be able to differentiate. This  starts with the supposition that central ring of one image must fall on the first dark ring of the other; for

  • Q : Define Sievert or SI unit of dose

    Sievert: Sv: The derived SI unit of dose equivalent, stated as the absorbed dose of the ionizing radiation multiplied by internationally-agreed-upon dimensionless weights, as various kinds of ionizing radiation cause various kinds of damage in the liv

  • 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 : Calculate the intensity I along y axis

    As shown in the figure below, a source at S is sending out a spherical wave: E1=(A×D/r) cos(wt-2πr/λ); where r is the distance to source