46 terms

This set is currently a work in progress. It will cover A Beka Book Physics Chapter 20: "The Refraction of Light" (pages 292-308).

optical density

term for a material's resistance to the transmission of light waves

wavelength, speed

When light enters a new medium, _____ and ___ change.

decrease

The wavelength of light entering an optically **denser** medium must _____.

increase

The wavelength of light entering a medium of **lower optical density** must ______.

refraction

term for the bending of light rays at the boundary between two media differing in optical density

transmitted

If two adjoining media have the same optical density, light is fully _____.

absorbed, reflected

If a new medium is nontransparent, light is partly ____ and partly _____.

transmitted, reflected

If both media are transparent, but have different optical densities, some light is ____ and some is ____.

refractive index

term for the index that relates the speed of light in a vacuum to the speed of light in a particular medium

refractometer

term an instrument that measures refractive index

angle of incidence

term for the angle between an incoming ray and the normal to the boundary

angle of refraction

term for the angle between a refracted ray and the normal to the boundary

n1 sin θ1 = n2 sin θ2

the first law of refraction

Snell's law

another term for the simple relationship expressed by the first law of refraction

principle of reversibility

principle that states that the path of a light ray subjected to reflection or refraction is traced in reverse by any ray coming along the path in the opposite reaction

mirage

A ____ of water is due to the refraction of sunlight as it passes through hot, expanding air at ground level.

critical angle

When the angle of incidence reaches the ____ ___, the angle of refraction becomes 90 degrees.

total internal reflection

term for reflection as a result of an angle of incidence greater than the critical angle

convex

term for a bulging surface with the same curvature as the surface of a sphere

concave

term for a caved-in surface witht he same curvature ast he surface of a sphere

planar

term to describe a flat surface

convergig lenses

term for lenses that redirect parallel rayst oward a point of convergence

double convex lenses

the most important converging lenses

diverging lenses

term for lenses that spread parallel rays apart

double concave lenses

the most important diverging lenses

positive

negative

normal

term for the perpendicular to a plane at the point of tangency

principal axis

term for the axis which is perpendicular to the lens plane

principal focal point

term for the point of convergence on the opposite side of the lens, to which rays are directed

optical center

term for the center of the lens

focal length

term for the distance from the optical center to the principal focal point

secondary focal point

another term for the focal length

optical plane

term for a plane perpendicular to the principal axis at the optical center

parallel ray

term for a ray that travels parallel to the principal axis, and then refracts through the mirror to the principal focal point

central ray

term for a ray that pases through the optical center of a lens without deviation on the far side

focal ray

term for a ray that aproaches the lens through the focal point

real image

term for actual light rays intersecting after refraction

virtual image

term for light rays extending from a lens in order to intersect

1/f = (n-1) (1/r1 - 1/r2)

the lensmaker equation

1/f = 1/do + 1/di

the thin lens equation

myopia and hyperopia

two defects of vision that can be corrected by wearing eyeglasses or contact lenses

myopia

term for nearsightedness

hyperopia

term for farsightedness

P = 1/f

the equation for the power of a lens

diopter

the unit for the power of a lens