Year 1 content

Question 1

What does random errors affect

Answer 1

precision

Question 2

What does systematic error affects

Answer 2

accuracy

Question 3

How are random errors mitigated (3)

Answer 3

1. reduce % uncertainty
2. take repeats
3. higher resolution
4. more resolution
5. use data loggers

Question 4

How are systematic errors mitigated (2)

Answer 4

1. calibrate equipment
2. check against known data values
3. control environment

Question 5

define parallax error

Answer 5

when a measurement is taken from the wrong point, due to viewing angle

Question 6

Difference between repeatability and reproducibility

Answer 6

repeat - tester redoing it
reproduce - 3rd party

Question 7

resolution for reading

Answer 7

1/2 of smallest division

Question 8

resolution for measurement

Answer 8

1 smallest division

Question 9

% uncertainty of set of data

Answer 9

1/2 of range

Question 10

% uncertainty for gradiant

Answer 10

(best m - worst m)/best m

Question 11

all SI units (7)

Answer 11

1. metre
2. kg
3. sec
4. mole
5. amps
6. candela
7. K

Question 12

Range of strong force

Answer 12

< 3 fm
repulsive under 0.5 fm

Question 13

alpha decay eq.

Answer 13

Question 14

how was anti-electron neutrino discovered

Answer 14

1. consitution of energy suggest energy(before) != energy(after)
2. suggest anotherb particle have been produced

Question 15

annhilation and pair production diagram

Answer 15

Question 16

what does E = mc^2 suggest

Answer 16

energy and mass are interchangable

Question 17

app. of annihlation (1,4 steps)

Answer 17

PET scanner
1. positron is emitted
2. annihlates electron in body
3. photons are released
4. detected to form 3D image

Question 18

exchange particle for strong force

Answer 18

gluon

Question 19

exchange particle for weak force

Answer 19

W boson ( +/-)

Question 20

exchnage particle for EM

Answer 20

photon

Question 21

feymann diagram for beta-plus decay

Answer 21

Question 22

feymann diagram for beta-minus decay

Answer 22

Question 23

feymann diagram for **electron capture **

Answer 23

Question 24

feymann diagram for electron-proton collision

Answer 24

Question 25

Why threshold frq. cannot be explained by wave theory

Answer 25

1. wave theory suggest photoelecton can be emitted under any frq. 2. contradicts reality 3. as only frq > frq 0 emits photo e-

Question 26

how particle theory backs threshold frq.

Answer 26

1. each EM wave travel in packets called photon 2. 1 electron absorbs 1 photon 3. electron is only emitted when energy is greater than work func.

Question 27

Define stopping potential

Answer 27

pd needed across metal to stop photoelectron with max KE

Question 28

5 key points for flourescent lamp

Answer 28

1. voltage acc. electron along the tube 2. electron collides with Hg atoms - *excitation * 3. Hg *dexcites* - releases UV 4. flourescent coating absorbs UV photons - *excitation * 5. coating *dexcites* - emitting **visible light** photons

Question 29

experiment that demonstrate particle properties of light

Answer 29

photoelectric effect

Question 30

# de Brogile wavelength - electron diffraction what happens when speed of electron increases

Answer 30

1. wavelength decreases 2. diffraction decreases 3. closer ring

Question 31

# 4 general rules of particles only stable baryon

Answer 31

proton

Question 32

# 4 general rules of particles how are strange particles created / decayed

Answer 32

1. produced in pair by strong 2. decay via weak

Question 33

# 4 general rules of particles what does muon decays into

Answer 33

electron (as from heavy electron)

Question 34

how to build mesons config.

Answer 34

1. one particle + one anti- 2. by charge 3. only kaon have stangeness

Question 35

formation of stationary waves (5)

Answer 35

1. foward wave emitted 2. hits boundary - form reflected wave 3. both conherent + constant phase difference 4. anti-node - constructive interference - in phase 5. node - destructive interference - anti-phase

Question 36

phase diff. - constructive

Answer 36

n λ

Question 37

phase diff. - destructive

Answer 37

(n+1/2) λ

Answer 38

Question 39

apperance of white light diffraction

Answer 39

1. white central maxima 2. showing a range of colour 3. with red furthest 4. violet closest

Question 40

condition for TIR

Answer 40

1.going from denser to less dense 2.angle greater than critical angle

Question 41

what is cladding

Answer 41

surrounding core with optically less dense material

Question 42

define pulse broadening

Answer 42

causes an overlap of signal, loss of info

Question 43

define material dispersion

Answer 43

causes ray to travel in different angle and speed [due to different wavelength] solution: monochromatic light

Question 44

define modal dispersion

Answer 44

caused by ray entering at different angle, taking varying paths solution : reduce diameter of core

Question 45

define plastic

Answer 45

does not return to orignial shape after deformation

Question 46

define brittle

Answer 46

little extension before frature under large force

Question 47

Kirchoff's 1st law

Answer 47

sum(flow in) = sum(flow out) at junction

Question 48

Kirchoff's 2nd law

Answer 48

emf = sum of voltage consumed

Question 49

potential divider eq.

Answer 49

## Footnote key info: current is same in series ( I1 =I2) v(R2) = Vout

Question 50

properties of ideal voltmeter and amnmeter

Answer 50

voltmeter - infinte resistance (short circuit) amnmeter - no resistance (like wire)

Question 51

how does resistance change when temp increases: [metal conductor]

Answer 51

1. greater vibration of atoms 2. more collision with electrons 3. greater resistance

Question 52

how does resistance change when temp increases: [ntc thermistor]

Answer 52

1. more electrons emitted 2. greater no. of charge carriers 3. greater current

Question 53

3 app. of superconductivity

Answer 53

1. power cable 2. strong magnetic fields - maglev train , medical scanners

Question 54

Define resonance

Answer 54

amplitude increases significantly when applied force = natural frq.

Question 55

Difference between free and forced oscillation

Answer 55

Free * no transfer of energy * only internal forces * always at resonance Forced * periodic force needed * to replace energy loss * WD on resistive forces

Question 56

Define critical damping

Answer 56

shortest time to return to rest without oscillation