Biophysics 8

Front 1

Define Light

Back 1

Electromagnetic radiation of any wavelength, whether visible or not.

Front 2

What is the range of all possible frequencies called?

Back 2

Electromagnetic spectrum.

Front 3

What is the short limit called?

Back 3

Planck's Length

Front 4

What is the electromagnetic spectrum of an object?

Back 4

The distribution of electromagnetic radiation emitted or absorbed by that particular object - spectrometry

Front 5

What did Gassendi discover?

Back 5

Particle theory of light.

Front 6

What did Newton discover?

Back 6

Light composed of corpuscles which were emitted in all directions from a source with a finite velocity and possess kinetic energy.

Front 7

What did Planck discover?

Back 7

Radiation of a black body through quanta, discreet bundles of electromagnetic energy, light particle = photon.

Front 8

What is the photoelectric effect?

Back 8

Electrons are emitted from matter as a consequence of absorption of energy from electromagnetic radiation of very short wavelengths, such as ultraviolet light.

Front 9

Name the three people who were involved in the wave theory and what they discovered.

Back 9

Hooke - first wave theory of light

Grimaldi - Diffraction of light.

Young - light waves can interfere with one and other like sound waves.

Front 10

What does light consist of?

Back 10

Photons

Front 11

What properties does the dual nature of light exhibit?

Back 11

Diffraction

Distortion

Interference

Front 12

What is the energy of a photon proportional to?

Back 12

Frequency

Front 13

What is a photon?

Back 13

An elementary particle, the quantum of electromagnetic interaction, the basic unit of light and all other forms of electromagnetic radiation and the force carrier for the electromagnetic force.

Front 14

What is colour temperature?

Back 14

The temperature of an ideal black body that radiates light of comparable hue.

Front 15

What is the distance measured between any two points of the wave with the same phases called?

Back 15

Wavelength

Front 16

Define frequency.

Back 16

Number of occurrences of a repeating event per unit time, temporal resolution events.

Front 17

What is the frequency of light directly proportional to?

Back 17

Wavelength and energy.

Front 18

What is the pressure exerted on any surface exposed to electromagnetic radiation called?

Back 18

Light pressure

Front 19

Define polarisation.

Back 19

The orientation of oscillations in the plane perpendicular to a transverse waves direction of travel.

Front 20

What did Faraday discover?

Back 20

Plane of polarisation of linearly polarised light is affected by the magnetic field (faraday rotation)

Front 21

Define Beer-Lamberts law?

Back 21

There is a logarithmic dependence between the transmission of light through a substance, the absorption coefficient of the substance and the distance the light travels through the material.

Front 22

What is the physical property of material allowing light to pass?

Back 22

Transparency

Front 23

Define Translucency.

Back 23

Allows light to pass through but diffusely.

Front 24

Define opaque.

Back 24

Materials which do not allow the transmition of light

Front 25

Name a photovoltaic process which converts carbon dioxide into organic compounds using energy from sunlight.

Back 25

Photosynthesis.

Front 26

What is phototropism?

Back 26

Directional growth of plants in which the direction of growth is determined by the direction of the light.

Front 27

Name the two blue light receptors.

Back 27

Phototropins

Cryptochromes

Front 28

Name the red light receptor.

Back 28

Phytochromes.

Front 29

Why does sunlight appear orange?

Back 29

Shorter wavelengths such as blue and green scatter more strongly and are removed almost completely from the incident beam leaving only red and orange.

Front 30

Why is the sea blue?

Back 30

Because water absorbs red and orange light more efficiently than green and blue.

Front 31

Shade

Back 31

Area where light is blocked

Front 32

Shadow

Back 32

an area where direct light from a source can't reach due to an obstruction by an opaque object.

Front 33

What is a ray of light?

Back 33

Idealized narrow beam of light.

Front 34

Refraction

Back 34

Bending of light while passing through a medium boundary due to the variation in speed.

Front 35

Dispersion

Back 35

Separation of different wavelengths comprised in a ray of light.

Front 36

An object with at least one reflective surface is called what?

Back 36

Mirror

Front 37

Dichroic mirror

Back 37

Accurate colour separators used to selectively pass light of a small range of colours while reflecting other colours.

Front 38

The measure of the speed of light is called what?

Back 38

Refractive index

Front 39

When does TIRF happen?

Back 39

When a ray of light strikes a medium boundary at an angle larger than a critical angel.

Front 40

What is the critical angle?

Back 40

The angle of incident above which TIRF occurs, the refractive index on the other side of the boundary is lower, so no light can pass through and all of the light is reflected.

Front 41

What are the three properties of light as a wave?

Back 41

Refraction

Diffraction

Interference

Front 42

Name the two types of light used in lightbulbs.

Back 42

Electroluminescence

Front 43

What type of light is used in TV?

Back 43

Phosphorescence.

Front 44

What is electroluminescence?

Back 44

Flow of electrical current.

Front 45

Name the four types of laser.

Back 45

Brilliant

Coherent

Collimated

Monochromatic

Front 46

Name the three properties of total darkness.

Back 46

Absence of light.

Absence of other wavelengths of electromagnetic spectrum.

True vacuum

Front 47

What is photochemistry?

Back 47

Interaction between light and atoms or other molecules.

Front 48

What is photography?

Back 48

Recoding of radiation on a radiation sensitive medium.