# Shared Flashcard Set

## Details

Chapter 30: Lenses Questions
Chapter 30: Lenses Questions
31
Physics
01/07/2012

Term
 Does a lens refract or reflect?
Definition
 refract
Term
 A lens refracts ____________ ________ of light so that they cross-or appear to cross- at a focal point.
Definition
 parallel rays
Term
 A converging lens is ____________ in the middle.
Definition
 thicker
Term
 A diverging lens is ___________ in the middle.
Definition
 thinner
Term
 A _____________ lens forms a magnified virtual image when the object is within one focal length of the lens.
Definition
 converging
Term
 Name 2 optical instruments that use lenses.
Definition
 Camera, telescope, compound microscope, projector
Term
 A diverging lens always forms reduced _____________ ___________.
Definition
 virtual images
Term
 True or False. The human eye reflects light.
Definition
 False. The eye lens refracts light.
Term
 The human eye focuses light on the _______________________.
Definition
 retina
Term
 A piece of glass that can bend parallel rays of light so that they cross, or appear to cross, at a single point is called a __________________.
Definition
 lens
Term
 The line joining the centers of curvature of the surface of the lens is called the ________ _________.
Definition
 principal axis
Term
 For a converging lens, the point at which a beam of light parallel to the principal axis converges is the _________ _______.
Definition
 focal point
Term
 For a ___________lens, the point from which a beam appears to come is called the focal point.
Definition
 diverging
Term
 For a diverging lens, name the plane that passes through the point where a beam appears to come from. (Must be perpendicular to the principal axis)
Definition
 Focal Plane
Term
 For a converging lens, a ________ passing through either focal point of a lens that is perpendicular to the principal axis is called the focal plane.
Definition
 plane
Term
 For a converging or diverging lens, the distance between the center of the lens and its focal point is called the _____________ ______________
Definition
 focal length
Term
 An image formed through ____________ or ________________ that can be seen by an observer but cannot be projected on a screen because light from the object does not come to a focus is called a _________ __________.
Definition
 reflectionrefractionvirtual image
Term
 An image that is formed by converging light rays that can be displayed on a screen is called a _____ _______.
Definition
 real image
Term
 A diagram showing rays that can be drawn to determine the size and location of an image formed by a mirror or lens is called a ______ __________.
Definition
 ray diagram
Term
 When a real image is formed, the object and image are on ___________ sides of the lens.
Definition
 opposite
Term
 Name the lens of a telescope closest to the eye that enlarges the real image formed by the first lens.
Definition
 eyepiece
Term
 In an optical device using compound lenses, the lens closest to the object observed is called the _________ _______.
Definition
 objective lens
Term
 The amount of light that enters the eye is regulated by the _____.
Definition
 iris
Term
 The opening in the eyeball through which light passes is called the _______.
Definition
 pupil
Term
 The transparent covering over the eyeball is called the _______.
Definition
 cornea
Term
 The layer of ____________-___________ tissue at the back of the eye is called the retina.
Definition
 lightsensitive
Term
 If a personâ€™s eye forms images _________ the retina, the person is called far-sighted.
Definition
 behind
Term
 A _____ - _______ person needs to wear converging lenses.
Definition
 far sighted
Term
 A person who can see nearby objects clearly but distant objects focus in front of the retina is called ____ sighted.
Definition
 near
Term
 Name the eye defect that occurs when the cornea is curved more in one direction than the other.
Definition
 Astigmatism
Term
 The distortions in a lensâ€™ image are called _____________________.
Definition
 aberrations
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