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Physics ch 30
CHAPTER 30 VOCABULARY
Question | Answer |
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lens | a piece of glass or other material that can bend parellel rays of light so that they cross or appear to cross, at a single point. |
converging lens | a lens that is thickest in the middle, causing parellel rays of light to converge to a focus |
convex lens | a lens that is thickest in the middle, causing parellel rays of light to converge to a focus |
diverging lens | a lens that is thinnest in the middle and that causes parallel rays of light to diverge |
concave lens | a lens that is thinnest in the middle and that causes parallel rays of light to diverge |
principal axis | the line joining the centers of curvature of the surfaces of a lens |
focal point | for a converging lens the point at which a beam of light parallel to the principal axis converges for a diverging lens the point from which such a beam appears to come. |
focal plane | a plane passing through either focal point of a lens that is perpendicular to the principal axis. converging lens any incident parallel beam of light converges. to a point somewhere on a focal plane. |
focal length | the distance between the center of a lens and either focall point |
real image. | an image that is formed by converging light rays and that can be displayed on a screen |
virtual image | an image formed through reflection or refraction that can be seen by an observer that can be seen by an observer but cannot be projected on a screen because light from the object does not actually come to a focus |
ray diagram | a diagram showing rays that can be drawn to determine the size and location of an image formed by a mirror or lens |
eye piece | lens of a telescope closest to the eye; enlarges the real image formed the first lens. |
objective lens | in an optical device using compound lenses the lens closest the object observed. |
cornea | the transparent covering over the eyeball |
iris | the colored part of the eye that surrounds the pupil. controls the light going in and out. |
pupil | the opeaning inthe eyeball through which light passes |
retina | the layer of light. sensitive tissue in back of the eye |
farsighted | term applied to a person who has trouble focusing on near by objects because the eyeball is to schort that images form behind the retine |
nearsighted | term applied to a person who can clearly see nearby objects but not clearly see distant objects. images form in front of the retina. |
astigmatism | defect of the eye caused when the cornea is curved more in one direction than in another. |
aberration | distortion in n image produced by a lens |
fovea | the part of the eye in the most center part where you have your sharpest vision |
blind spot | a part of the eye where the image/vision is not recieved |
accommodation | the process by which the vertebrate eye changes optical power to maintain a clear image on an object. |