Unit 1

Question 1

What does coherent mean in terms of waves?

Answer 1

Constant phase difference

Question 2

What is produced when there is a bright fringe?

Answer 2

Maxima, in-phase, constructive interference

Question 3

What is produced at dark fringes?

Answer 3

Minimum, out-of-phase, destructive interference

Question 4

If wavelength is decreased what happens to the maxima separation?

Answer 4

Decreases

Question 5

What colour of light diffracts the furthest?

Answer 5

Red, longer wavelengths

Question 6

What is the test for wave behaviour?

Answer 6

Causing an interference pattern

Question 7

Explain Young’s double split experiment?

Answer 7

• splits one source of light into two
• produces coherent light waves
• interference pattern

Question 8

What happens when white light passes through a diffraction grating?

Answer 8

Central order maximum is white, remaining maxima are spectra

Question 9

Why does white light produce a white central order maxima?

Answer 9

All wavelength meet in-phase, constructive interference

Question 10

What effect does increasing the slit separation have on the interference pattern?

Answer 10

Decreases fringe separation

Question 11

What is refraction?

Answer 11

When light changes speed as it passes from one material to another

Question 12

What is absolute refractive index?

Answer 12

The ratio of the speed of the incident ray in a vacuum to the speed of the refracted light in the material

Question 13

Angle theta (01) is always the angle in what?

Answer 13

Air

Question 14

Will a longer wavelength diffract more or less?

Answer 14

Less diffraction

Question 15

What is the critical angle?

Answer 15

Angle of incidence that causes light to refract at 90 to the surface

Question 16

When does total internal reflection occur?

Answer 16

If the angle of incidence is increased above the critical angle

Question 17

What is irradiance?

Answer 17

The power per unit area

Question 18

What is a point source?

Answer 18

Source of light that appears to have no dimensions to the observer

Question 19

When does the irradiance of a point source decrease?

Answer 19

As the distance increases

Question 20

When is a spectrum produced?

Answer 20

By photons of light being emitted, as electrons make downwards transitions between energy levels within an atom

Question 21

Does an upward transition absorb or emit energy?

Answer 21

Absorbs

Question 22

When will an electron make a transition?

Answer 22

If the energy of the absorbed photon equals the amount of energy needed to move between levels

Question 23

Which level is the excited state?

Answer 23

E1

Question 24

Will a smaller drop on the emission spectrum produce a shorter or longer wavelength?

Answer 24

Longer

Question 25

What is all matter made of?

Answer 25

Fermions

Question 26

Name the two types of fermions?

Answer 26

Quarks, leptons

Question 27

What are hadrons made of?

Answer 27

Quarks

Question 28

Name the two types of hadrons

Answer 28

Baryon and messon

Question 29

Name the force carrying particle

Answer 29

Boson

Question 30

What is antimatter?

Answer 30

Identical to matter except they have opposite charge

Question 31

What is annihilation?

Answer 31

When matter and antimatter meet they annihilate each other, leaving behind energy

Question 32

What was discovered during beta decay?

Answer 32

Electron neutrino

Question 33

What acts on masses?

Answer 33

Gravity

Question 34

What does electromagnetism act on?

Answer 34

Charges

Question 35

What type of force acts during beta decay?

Answer 35

Weak nuclear force

Question 36

What force acts between quarks?

Answer 36

Strong nuclear force

Question 37

What is conserved during particle interactions?

Answer 37

Charge

Question 38

What is an electric field?

Answer 38

The region where a charge will experience a force

Question 39

Why do charges accelerate in an electric field?

Answer 39

Due to an unbalanced force

Question 40

What way do the arrows point on a positive charge?

Answer 40

Point away

Question 41

What way do the arrows point on a negative charge?

Answer 41

Points towards point

Question 42

What does a potential difference of 2.5kV mean?

Answer 42

2500J needed to move 1 coloumb of charge across electric field from one plate to another

Question 43

What are the 3 types of particle accelerators?

Answer 43

Linear accelerator, cyclotron, synchrotron

Question 44

What does a particle accelerator do?

Answer 44

Causes particles to collide with each other

Question 45

Why are particle accelerators important?

Answer 45

At high energies can recreate conditions at Big Bang and investigate the particles that existed

Question 46

What is a magnetic field?

Answer 46

A region that can exert a force on a charge

Question 47

What kind of charge creates an electric field?

Answer 47

Stationary charge

Question 48

What kind of field does a moving charge create?

Answer 48

Magnetic field

Question 49

When using the right hand rule what does the middle finger represent?

Answer 49

Negative charge or current

Question 50

What symbol is used to represent the field lines pointing into page?

Answer 50

X

Question 51

What is a (.) used to represent in terms of field lines?

Answer 51

Field lines point out of page

Question 52

What is a nuclide?

Answer 52

Nucleus with a specific number of protons and neutrons

Question 53

Define an isotope

Answer 53

Nuclides with the same atomic number but different mass number

Question 54

When a radionuclide decays what does it emit?

Answer 54

Radiation or particles to become a more stable daughter product

Question 55

What type of nuclear fission occurs naturally?

Answer 55

Spontaneous nuclear fission

Question 56

How does induced nuclear fission occur?

Answer 56

Large nucleus is bombarded with a neutron which splits the nucleus into smaller nuclei with the realise of energy and neutrons

Question 57

How does an induced nuclear fission reaction release energy?

Answer 57

The total mass before is greater than the total mass after. The loss in mass is converted into energy using E=mc^2

Question 58

During nuclear fission what is conserved?

Answer 58

Atomic and mass number

Question 59

What is nuclear fusion?

Answer 59

When two smaller nuclei join to make a larger nucleus

Question 60

What are quanta of energy?

Answer 60

Fixed or discrete amount of energy, directly proportional to frequency

Question 61

What are photons?

Answer 61

Quanta of energy

Question 62

What is the photoelectric effect?

Answer 62

Photon energy is absorbed by the electron and becomes a free electron

Question 63

What type of emission is best for the photoelectric effect?

Answer 63

A UV photon

Question 64

What type of charges need to be present in the metal for the photoelectric effect to work?

Answer 64

Negative charges

Question 65

What does the metallic surface need to have for photoelectric emission?

Answer 65

Low enough work function/ threshold frequency

Question 66

What quarks make up a baryon?

Answer 66

3 quarks or 3 anti-quarks

Question 67

What quarks make up a messon?

Answer 67

1 quark and 1 anti-quark

Question 68

Give an example of a meson

Answer 68

Pion

Question 69

What happens to the photoelectric current as photon energy increases

Answer 69

Photoelectric current increases

Question 70

Define work function

Answer 70

Minimum amount of energy needed to bring an electron to the surface of the metal

Question 71

Define threshold frequency

Answer 71

Minimum frequency an incident photon needed to bring an electron the surface of the metal