critical angle

critical angle
1. Optics. the minimum angle of incidence beyond which total internal reflection occurs for light traveling from a medium of higher to one of lower index of refraction; the angle of incidence for which refracted rays emerge tangent to the surface separating two media, the light traveling from the medium of higher to the medium of lower index of refraction.
2. Also called angle of stall, critical angle of attack, stalling angle. Aeron. the angle of attack, greater than or equal to the angle of attack for maximum lift, at which there is a sudden change in the airflow around an airfoil with a subsequent decrease in lift and increase in drag.
[1870-75]

* * *

▪ optics
      in optics, the greatest angle at which a ray of light, travelling in one transparent medium, can strike the boundary between that medium and a second of lower refractive index without being totally reflected within the first medium. (The refractive index of a transparent substance is the ratio of the speed of light in a vacuum to its speed in that substance.) For any angle of incidence smaller than the critical angle, and for any angle at all if the ray strikes the boundary from the other side, part of the beam will penetrate the boundary, being refracted in the process.

* * *


Universalium. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Critical angle — Critical Crit ic*al (kr[i^]t [i^]*kal), a. [See {Critic}, n., {Crisis}.] [1913 Webster] 1. Qualified to criticise, or pass judgment upon, literary or artistic productions. [1913 Webster] It is submitted to the judgment of more critical ears to… …   The Collaborative International Dictionary of English

  • Critical angle — can refer to: Critical angle (optics) the angle of incidence above which total internal reflection occurs Critical angle of attack, in aerodynamics; the angle of attack which produces the maximum lift coefficient Critical angle of repose, in… …   Wikipedia

  • critical angle — n. 1. Optics the smallest possible angle of incidence at which light rays are totally reflected 2. Aeron. that angle of attack at which the flow of air around an airfoil suddenly changes, with an abrupt reduction in lift and an increase of drag:… …   English World dictionary

  • critical angle — i. The minimum angle of incidence at which a radio wave of a particular frequency can strike the ionosphere and still be reflected back to the earth. Critical angle is a function of frequency; the higher the frequency, the larger the critical… …   Aviation dictionary

  • critical angle — ribinis kampas statusas T sritis fizika atitikmenys: angl. critical angle vok. Grenzwinkel, m rus. предельный угол, m pranc. angle critique, m; angle limite, m …   Fizikos terminų žodynas

  • critical angle — kritinis kampas statusas T sritis fizika atitikmenys: angl. critical angle vok. kritischer Winkel, m rus. критический угол, m pranc. angle critique, m …   Fizikos terminų žodynas

  • critical angle of attack — noun see critical angle 2 …   Useful english dictionary

  • critical angle — noun the smallest angle of incidence for which light is totally reflected • Hypernyms: ↑angle of incidence, ↑incidence angle …   Useful english dictionary

  • critical angle — noun a) The smallest angle of incidence for which light is totally reflected from a boundary between one medium and a less refractive one b) The smallest angle of attack of an airfoil at which lift suddenly decreases and drag suddenly increases …   Wiktionary

  • critical angle — crit′ical an′gle n. 1) opt the minimum angle of incidence beyond which total internal reflection occurs for light traveling from a medium of higher to one of lower index of refraction 2) aer. the angle of attack at which a sudden change in… …   From formal English to slang

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”