principal axis

  1. Optics. a line passing through the center of the surface of a lens or spherical mirror and through the centers of curvature of all segments of the lens or mirror.

  2. Physics. one of three mutually perpendicular axes of a body about which the moment of inertia is maximum or minimum.

Origin of principal axis

First recorded in 1875–80

Words Nearby principal axis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use principal axis in a sentence

  • These are at points on the principal axis that are twice as far from O, the center of the lens, as are the principal foci.

    Physics | Willis Eugene Tower
  • In the stauraxonia the vertical imaginary principal axis is cut by two or more horizontal cross-axes or radial-axes.

    The Wonders of Life | Ernst Haeckel
  • Direct nitration gives (principally) m-nitrobenzoic acid, also pseudo-tetragonal with a much shorter principal axis.

  • Benzoic acid is pseudo-tetragonal, the principal axis being remarkably long; there is no cleavage at right angles to this axis.

  • The intersection of this last line with the principal axis will give the optical center.

    Visual Signaling | Signal Corps United States Army

British Dictionary definitions for principal axis

principal axis

  1. the line passing through the optical centre and centres of curvature of the faces of a lens or a curved mirror

  2. any of three mutually perpendicular axes about which the moment of inertia of a body is maximum

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012