Fundamentals of Light

Question 1

a stream of fast-moving, unimaginably tiny particles

Answer 1

corpuscles

Question 2

Light is represented as a ray that travels in a straight path.
The direction of which can be changed only by placing an obstruction in the path

Answer 2

ray model of light

Question 3

major source of light

Answer 3

Sun

Question 4

An object that emits light

Answer 4

Luminous Source

Question 5

An object that becomes visible as a result of the light reflecting off it.

Answer 5

Illuminated Source

Question 6

Media that do not transmit light but reflect some light

Answer 6

Opaque Media

Question 7

Media that transmit light, such as air and glass,

Answer 7

Transparent Media

Question 8

Media that transmit light but do not permit objects to be seen clearly

Answer 8

Translucent media

Question 9

They not only transmit light, but they also can reflect a fraction of the light.

Answer 9

Transparent or translucent media

Question 10

The rate at which light energy is emitted from a luminous source.

Answer 10

luminous flux, P

Question 11

The illumination of a surface, or the rate at which light strikes the surface

Answer 11

Illuminance, E

Question 12

Illuminance is measured in?

Answer 12

lux, lx

Question 13

a measure of luminous intensity

Answer 13

Candela

Question 14

luminous intensity

Answer 14

luminous flux divided by 4pi.

Question 15

Point Source Illuminance

Answer 15

Lux [lx] = luminous flux [lm] / area [m2]

Question 16

If r is constant, then E is directly proportional to P

Answer 16

When P increases, E increases

When P decreases, E decreases

Question 17

If P is constant, then E is
inversely proportional to r^2

Answer 17

When r 2 increases, E decreases.

When r 2 decreases, E increases.

Question 18

He was the first to determine that light
does travel with a measurable speed.

Answer 18

Ole Roemer

Question 19

known value of the diameter of Earth’s orbit

Answer 19

(2.9*10^11 m)

Question 20

speed of light in a vacuum

Answer 20

c = 299,792,458 m/s.

Question 21

a light-year

Answer 21

9.46x10^12 km

Question 22

the bending of light around a barrier

Answer 22

diffraction

Question 23

the ordered arrangement of colors

Answer 23

spectrum

Question 24

primary colors

Answer 24

red, green, and blue

Question 25

secondary colors

Answer 25

yellow, cyan, and magenta

Question 26

Two colors of light that can be combined to make white light.

Answer 26

Complementary colors

Question 27

a molecule that absorbs certain wavelengths of light and transmits or reflects others

Answer 27

Dye

Question 28

A pigment that absorbs only the primary color and reflects two from white light is called

Answer 28

primary pigment

Question 29

A pigment that absorbs two primary colors and reflects one color is called

Answer 29

secondary pigment

Question 30

the colors of primary pigments

Answer 30

Yellow, cyan, and magenta

Question 31

The colors of secondary pigments

Answer 31

red (which absorbs green and blue light), green (which absorbs red and blue light), and blue (which absorbs red and green light)

Question 32

the production of light in a single plane of oscillation

Answer 32

Polarization

Question 33

They contain long molecules in which electrons can oscillate, or move back and forth. all in the same direction.

Answer 33

Polarizing media

Question 34

The direction of a polarizing medium perpendicular to the long molecules is called

Answer 34

polarizing axis

Question 35

The law that explains the reduction of light intensity as it passes through a second polarizing filter is called

Answer 35

Malus’s law

Question 36

A positive change in wavelength means

Answer 36

the light is red-shifted

Question 37

A negative change in wavelength means

Answer 37

the light is blue-shifted

Question 38

Used to measure the Doppler shift of these wavelengths

Answer 38

spectrometer

Question 39

In 1929, he suggested that the universe is expanding

Answer 39

Edwin Hubble

Question 40

In what year did Edwin Hubble suggested that the universe is expanding?

Answer 40

1929