Ch. 21 Optical Properties

Question 1

Lightspeed

Answer 1

3 x 10 ^ 8

Question 2

C = ??

Answer 2

C = Frequency * Wavelength

Question 3

Energy of photon formula

Answer 3

E = h (plancks constant) * v

Question 4

Light interaction with solids formula

Answer 4

I0 = It (transmitted) + Ia (absorved) + Ir (reflected)

Question 5

Electron can jump to higher energy level if hit by…

Answer 5

photon (excited state)

Question 6

Electron jump to energy level same as

Answer 6

energy of photon

Question 7

Optical properties of metals

Answer 7

they can absorb a lot of light frequencies

Question 8

Surface required of metals to absorb photons

Answer 8

0.1 micrometers

Question 9

When e- stops being excited, it releases a -

Answer 9

photon

Question 10

% of light reflected

Answer 10

rest is heat

Question 11

Reflectivity of metals formula

Answer 11

= Ir / I0

Question 12

The atom gets distorted when…

Answer 12

it emits light

Question 13

Index of refraction formula

Answer 13

n = c / v

Question 14

Total internal reflectance formula

Answer 14

n1 / n2 = sin θ2 / sin θ1

Question 15

what is θc

Answer 15

angle where the reflacted light acts between both materialsR

Question 16

Reflection of non-metals

Answer 16

R = ( (n2 - n1) / (n2 + n1) ) ^2

Question 17

Absorption of light of frequency v by e- occurs if

Answer 17

hv > Egap

Question 18

Blue light energy

Answer 18

hv = 3.1 ev

Question 19

Red light energy

Answer 19

hv = 1.7 ev

Question 20

Egap

Answer 20

Opaque - 1.7 - Colored - 3.1 - Transparent

Question 21

Translucency is caused by:

Answer 21

caused by inside scattering

Question 22

Translucency can be caused by

Answer 22

grain boundaries, fine pores, phases

Question 23

Amorphous pore free polymers are:

Answer 23

transparent

Question 24

Semi crystalline polymers are:

Answer 24

transluscent or opaque, depends on %crystallinity, boundaries causes scattering

Question 25

If residence time is > 10^-8s

Answer 25

phosphorescenic

Question 26

if residence time is < 10^-8s

Answer 26

fluorescence

Question 27

Photoconductivity process

Answer 27

photon hits semiconductor - e- transitions to conduction band - profit?

Question 28

LEDs (light emmiting diode) process

Answer 28

EXPLAIN

Question 29

LASER stands for

Answer 29

Light amplification by the stimulated emission of radiation

Question 30

Distance between laser mirrors is

Answer 30

2L = Nλ

Question 31

Bouncing of light is fixed by:

Answer 31

step index