S5 - Physics Unit 2

Question 1

What is refraction?

Answer 1

The change in velocity and wavelength of light as it enters another medium

Question 2

What happens to the frequency when light enters another medium?

Answer 2

Nothing

Question 3

What are the blanked out words?

Answer 3

Question 4

What is the symbol for the refractive index?

Answer 4

n

Question 5

What units does refractive index have?

Answer 5

None

Question 6

What is a critical angle?

Answer 6

An angle at which light neither reflects nor refracts

Question 7

What angle does light leave a material at when it’s at its critical angle?

Answer 7

90°

Question 8

What is ‘total internal reflection’?

Answer 8

When the incident angle is greater than the critical angle and the light reflects within the material

Question 9

What are some uses of total internal reflection?

Answer 9

Transmitting internet signals through fibre optic cables

Question 10

How do we find the difference between two orders of magnitude?

Answer 10

We divide the two and count the number of numbers after the first number in our answer. The number of numbers is the difference of magnitudes

Question 11

What is the standard model?

Answer 11

Question 12

What make up hadrons?

Answer 12

Quarks

Question 13

What are examples of hadrons?

Answer 13

Protons and neutrons

Question 14

What is a proton made up of?

Answer 14

2 up quarks and a down quark

Question 15

What is the charge of an up quark?

Answer 15

+2/3

Question 16

What is the charge of a down quark?

Answer 16

-1/3

Question 17

What is a neutron made up of?

Answer 17

2 down quarks and 1 up quark

Question 18

What name is given to hadrons with 3 quarks?

Answer 18

Baryons

Question 19

What are quark-antiquark pairs known as?

Answer 19

Mesons

Question 20

What properties do mesons have?

Answer 20

They are unstable and do not exist for long

Question 21

What is the equation of beta decay involving neutrinos?

Answer 21

Question 22

What is a photon?

Answer 22

A wave on the electromagnetic spectrum

Question 23

What is a gluon?

Answer 23

A strong force which holds protons together in the nucleus

Question 24

What are Z and W bosons?

Answer 24

Weak forces responsible for radioactive decay

Question 25

What is a Higgs boson?

Answer 25

Responsible for giving particles a mass

Question 26

What do all particles in the standard model have in common?

Answer 26

They all have anti-particles

Question 27

What charge do anti-particles have?

Answer 27

The opposite to whatever particle it is 'anti' to

Question 28

What is a use of a particle collider?

Answer 28

To detect particles by colliding other particles together

Question 29

What happens in alpha decay?

Answer 29

A helium nucleus is emitted therefore the atomic number of an element is reduced by 2 and its mass number by 4

Question 30

What happens in beta decay?

Answer 30

A neutrino becomes a proton and emits an electron in the process therefore the mass number of the element stays the same and the atomic number is increased

Question 31

What form does light take?

Answer 31

Particle and wave

Question 32

What is the threshold frequency?

Answer 32

The minimum frequency required for a photon to knock an electron off something

Question 33

What do fermions consist of?

Answer 33

Quarks and leptons

Question 34

What equation can be used to find the threshold frequency?

Answer 34

fo = W/h

Question 35

What is the work function?

Answer 35

The minimum amount of energy an electron needs to leave an atom

Question 36

What is irradiance?

Answer 36

The brightness of radiation (light)

Question 37

What symbol does irradiance have?

Answer 37

I

Question 38

What is irradiance measured in?

Answer 38

Wm^-2

Question 39

Irradiance and distance are an ...

Answer 39

inverse square relationship

Question 40

What do we have to consider when carrying out the inverse square law experiment

Answer 40

Have to account for background light levels

Question 41

What is interference?

Answer 41

When two waves meet

Question 42

What is interference evidence of?

Answer 42

The wave nature of light

Question 43

What is it called when two identical waves collide?

Answer 43

Constructive interference

Question 44

What is it called when two dissimilar waves collide?

Answer 44

Destructive interference

Question 45

What happens in constructive and destructive interference?

Answer 45

- Amplitude / size of the trough doubles - Waves cancel out

Question 46

What happens when waves are and aren't "in phase"?

Answer 46

- Constructive interference takes place - Destructive interference takes place