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critical angle
critical anglen.1. The smallest angle of incidence at which a light ray passing from one medium to another less refractive medium can be totally reflected from the boundary between the two.2. The angle of attack of an airfoil at which airflow abruptly changes, causing changes in the lift and drag of an aircraft.critical angle n 1. (General Physics) the smallest possible angle of incidence for which light rays are totally reflected at an interface between substances of different refractive index 2. (Aeronautics) another name for stalling angle crit′ical an′gle
n. 1. 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. the angle of attack at which a sudden change in airflow occurs around the wings of an aircraft, reducing lift and increasing drag. [1870–75] crit·i·cal angle (krĭt′ĭ-kəl) The smallest angle of incidence at which a light ray can be completely reflected from the boundary between two media.Thesaurus| Noun | 1. | critical angle - the smallest angle of incidence for which light is totally reflectedangle of incidence, incidence angle - the angle that a line makes with a line perpendicular to the surface at the point of incidence |
critical angle
critical angle: see refractionrefraction,
in physics, deflection of a wave on passing obliquely from one transparent medium into a second medium in which its speed is different, as the passage of a light ray from air into glass.
..... Click the link for more information. .critical angle[′krid·ə·kəl ¦aŋ·gəl] (architecture) The angle of pitch of a flight of stairs or a ramp that, if exceeded, is considered uncomfortable and unsafe; it is 50° for stairs and 20° for ramps. (physics) An angle associated with total reflection of electromagnetic or acoustic radiation back into a medium from the boundary with another medium in which the radiation has a higher phase velocity; it is the smallest angle with the normal to the boundary at which total reflection occurs. critical angleAn angle of pitch of stairs or a ramp which is considered uncomfortable and unsafe if exceeded; this angle is 50° for stairs and 20° for ramps.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 angle.
ii. The angle of attack of an airfoil at which the flow of air about the airfoil changes abruptly in such a manner that the lift is sharply reduced and the drag is sharply increased. Sometimes called stalling angle of attack.
iii. The angle at which a reflected ray of light when transmitted from a denser to a rarer medium is bent so far from the normal that it does not enter the rarer medium at all but travels parallel to the surface between the media.
iv. The angle of bank beyond which a helicopter resting on the ground on one skid or one wheel is likely to roll over in an uncontrolled manner.
At the instant of rollover of a helicopter, a moment is produced by the horizontal component of total rotor thrust about the point of ground contact of the skid. This moment is opposed by weight of the aircraft. If the angle of bank is beyond the critical angle the restoring moment is too small to stop the helicopter from rolling over.critical angleIn an optical fiber, the maximum angle from the axis at which light can remain confined within the core for "total internal reflection." In contrast to the "acceptance angle," which is measured outside the fiber, the critical angle is a measurement within the fiber. See numerical aperture.critical angle
crit·i·cal an·glethe angle of incidence at which a ray of light, in passing between two media, changes from refraction to total reflection. Synonym(s): limiting anglecritical angle
Words related to critical anglenoun the smallest angle of incidence for which light is totally reflectedRelated Words- angle of incidence
- incidence angle
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