Test 4

Question 1

converging lens

Answer 1

a convex lens in which light rays that enter it parallel to its axis converge at a single point on the opposite side

Question 2

converging mirror

Answer 2

a concave mirror in which light rays strike it parallel to its axis converge at one or more points along the axis

Question 3

corner reflector

Answer 3

an object consisting of two mutually perpendicular reflecting surfaces, so that the light that enters is reflected back exactly parallel to the direction from which it came

Question 4

critical angle

Answer 4

the incident angle that produces an angle of refraction of 90 degrees

Question 5

dispersion

Answer 5

spreading of white light into its full spectrum of wavelengths

Question 6

diverging lens

Answer 6

a concave lens in which light rays that enter it parallel to its axis bend away (diverge) from its axis

Question 7

fiber optics

Answer 7

transmission of light down fibers of plastic or glass, applying the principle of total internal reflection

Question 8

focal length

Answer 8

distance from the center of a lens or curved mirror to its focal point

Question 9

focal point

Answer 9

for a converging lens or mirror, the point at which converging light rays cross; for a diverging lens or mirror the point from which diverging light rays appear to originate

Question 10

geometric optics

Answer 10

part of optics dealing with the ray aspect of light

Question 11

index of refraction

Answer 11

for a material, the ratio of the speed of light in vacuum to that in the material

Question 12

law of reflection

Answer 12

angle of reflection equals the angle of incidence

Question 13

magnification

Answer 13

ratio of image height to object height

Question 14

mirror

Answer 14

smooth surface that reflects light at specific angles, forming an image of the person or object in front of it

Question 15

power

Answer 15

inverse of focal length

Question 16

ray

Answer 16

straight line that originates at some point

Question 17

real image

Answer 17

image that can be projected

Question 18

refraction

Answer 18

changing of a light ray’s direction when it passes through variations in matter

Question 19

virtual image

Answer 19

image that cannot be projected

Question 20

zircon

Answer 20

natural gemstone with large index of refraction

Question 21

axis of a polarizing filter

Answer 21

direction along which the filter passes the electric field of an EM wave

Question 22

birefringent

Answer 22

crystals that split an unpolarized beam of light into two beams

Question 23

Brewster’s angle

Answer 23

(theta)b= inverse tan(n2/n1)
n2= the index of refraction of the medium from which the light reflected 
n1= the index of refraction of the medium in which the reflected light travels

Question 24

Brewster’s law

Answer 24

tan(theta)b= n2/n1
n1= is the medium in which the incident and reflected light travel and n2 is the index of refraction of the medium that forms the interface that reflects the light

Question 25

coherent

Answer 25

waves are in phase or have a definite phase relationship

Question 26

confocal microscopes

Answer 26

microscopes that use the extended focal region to obtain 3D images rather than 2D images

Question 27

Constructive interference for a double slit

Answer 27

the path length difference must be an integral multiple of the wavelength

Question 28

contrast

Answer 28

the difference in intensity between objects and the background on which they are observed

Question 29

Constructive interference for a diffraction grating

Answer 29

occurs when the condition: d * sin(theta)= m* (lambda) (for m= 0, 1, -1, 2, -2) d= distance between slits in the grating (lambda)=Is the wavelength of light m= is the order of the maximum

Question 30

destructive interference for a double slit

Answer 30

the path length difference must be an integral multiple of the wavelength

Question 31

destructive interference for a single slit

Answer 31

occurs when D*sin(theta)= m* (lambda) (for m= 0, 1, -1, 2, -2) D= is the slit width (lambda)= the light's wavelength (theta)= is the angle relative to the original direction of the light, and m is the order of the minimum

Question 32

diffraction

Answer 32

The bending of a wave around edges of an opening or an obstacle

Question 33

diffraction grating

Answer 33

a large number of evenly spaced parallel slits

Question 34

direction of polarization

Answer 34

the direction parallel to the electric field for EM waves

Question 35

horizontally polarized

Answer 35

the oscillations are in a horizontal wave

Question 36

Huygens' principle

Answer 36

Every point on a wavefront is a source of wavelets that spread out in the forward direction at the same speed as the wave itself. The new wavefront is a line tangent to all of the wavelets.

Question 37

incoherent

Answer 37

waves that have random phase relationships

Question 38

interference microscopes

Answer 38

microscopes that enhance contrast between objects and background by superimposing a reference beam of light upon the light emerging from the sample

Question 39

optically active

Answer 39

substances that rotate the plane of polarization of light passing through them

Question 40

order

Answer 40

the integer m used in the equations for constructive and destructive interference for a double slit

Question 41

phase-contrast microscope

Answer 41

microscope utilizing wave interference and differences in phases to enhance contrast

Question 42

polarization

Answer 42

the attribute that wave oscillations have a definite direction

Question 43

Rayleigh criterion

Answer 43

two images are just as resolvable when the center of the diffraction pattern of one is directly over the first minimum of the diffraction pattern of the other

Question 44

reflected light that is completely polarized

Answer 44

light reflected at the angle of reflection (theta)b, known as Brewster's angle

Question 45

thin film interference

Answer 45

interference between light reflected from different surfaces of a thin film

Question 46

Ultraviolet (UV) microscopes

Answer 46

microscopes constructed with special lenses that transmit UV rays and utilize photographic or electronic techniques to record images

Question 47

unpolarized

Answer 47

waves that are randomly polarized

Question 48

vertically polarized

Answer 48

the oscillations are in a vertical plane

Question 49

wavelength in a medium

Answer 49

(lambda)n= (lambda)/n (lambda)=the wavelength in vacuum n= the index of refraction of the medium