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Waves in air; fluids; solids

Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves

Sub-Topic Waves in air; fluids; solids

Difficulty Level Bronze Level

Booklet Mark Scheme 1

Time Allowed: 55 minutes

Score: /54

Percentage: /100



M1. (a) K 1

(b) Decreases 1

(c) use a metre rule / 30 cm ruler to measure across 10 (projected) waves

accept any practical number of waves number for 10 1

and then divide by 10 1

(d) 1.2 cm = 0.012 m 1

18.5 × 0.012 = 0.22(2) (m / s) 1

allow 0.22(2) with no working shown for 2 marks

typical walking speed = 1.5m / s

accept any value e.g. in the range 0.7 to 2.0 m / s 1

so the water waves are slower (than a typical walking speed)

this cannot score on its own 1

[8]



M2. (a) (i)

correct order essential

(A =) a microphone 1

(B =) an oscilloscope

or cathode ray oscilloscope or CRO 1

(ii) the amplitude

accept any unambiguous indication 1

(iii) quieter / softer

do not accept less (which could refer to the amplitude, frequency or wavelength)

1

(b) sound cannot travel through a vacuum / (empty) space / free space

accept there is no medium for the sound to travel through 1

(because) there is / are nothing / no particles to vibrate

accept (because) there is / are nothing / no particles between them and the source (of the sound)

1

[6]



M3. (a) (i) 25 (%)

do not accept ¼ 1

(ii) increases 1

(b) tick ( ) in top and bottom box

both required 1

(c) SHINY surfaces are good reflectors of infra-red radiation

accept white for shiny

or black surfaces are POOR reflectors of infra-red radiation

accept bad for poor accept insertion of ‘not’ before ‘good’ in statement

or black surfaces are good EMITTERS of infra-red radiation

or black surfaces are good ABSORBERS of infra red radiation 1

[4]

-



M4. (a) (i) J and L

both required, either order 1

(ii) K 1

(iii) L 1

highest frequency

reason does not score if L not chosen

accept most waves (on screen)

do not accept frequency above 20 000(Hz)

do not accept cannot hear it 1

(b) transmitter

detector

computer

all three in correct order

allow 1 mark for one correct 2

[6]



M5. (a) vibrate

allow move more (vigorously) but not just move 1

dirt / muck / grit / rust / dust etc.

do not accept bacteria 1

(b) any one medical use eg

ignore incorrect biological detail

• scanning unborn babies

• destroying (kidney) stones 1

(c) (i) 2 1

(ii) C 1

[5]



M6. (a) (i) bat(s) 1

(ii) any example in the inclusive range 5 ↔ 29 Hz / hertz

appropriate number and unit both required 1

(b) (i) A, C, D

all three required and no other 1

(ii) D, E

both required and no other 1

(c) sound cannot travel through a vacuum / (empty) space / free space

accept there is no medium (for the sound to travel through)

do not accept there is no air (for the sound to travel through) 1

(because) there is / are nothing / no particles to vibrate

accept because there is / are nothing / no particles between them and the source (of the sound)

1

[6]



M7. (a) (i) wavelength

accept frequency

accept speed 1

(ii) amplitude

accept energy height is insufficient

1

(iii) sound 1

(b) 0.12

allow 1 mark for correct substitution, ie 8 × 0.015 provided no subsequent step shown

2

metre per second or m/s or metre/second

do not accept mps units must be consistent with numerical answers

1

[6]



M8. (a) pitch 1

loudness 1

(b) (i) as length (of prongs) decreases frequency / pitch increases

accept converse

accept negative correlation

ignore inversely proportional 1

(ii) 8.3 (cm)

accept 8.3 ± 0.1 cm 1

(iii) (8.3 cm is) between 7.8 (cm) and 8.7 (cm)

ecf from part (ii) 1

(so f must be) between 384 (Hz) and 480 (Hz) 1

410 (Hz) ≤ f ≤ 450 (Hz)

if only the estimated frequency given, accept for 1 mark an answer within the range

1

(c) (i) electronic 1

(ii) frequency is (very) high

accept frequency above

20 000 (Hz) or audible range 1



so tuning fork or length of prongs would be very small (1.2 mm) 1

(d) 285.7 (Hz)

accept any correct rounding 286, 290, 300

allow 2 marks for 285

allow 2 marks for correct substitution 0.0035 = 1 / f

allow 1 mark for T = 0.0035 s

allow 1 mark for an answer of 2000 3

[13]



Page 1


Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves


Difficulty Level Silver Level



Score: /53

Percentage: /100



Page 2

M1. (a) any two from:

• (sound with frequency) above 20 000 hertz / 20 kHz

• frequencies above (human) audible range

• (sound) cannot be heard by humans 2

(b) either two appropriate points gain 1 mark each

either both pro / con or one of each

orone appropriate point (and) appropriate qualification / amplification

examples other mammals (sufficiently) similar to humans (1)

so results appropriate (1)

unethical to experiment on humans (1)

so it is better to experiment on mice (1)

knowledge / techniques will benefit humans (1) and also other animals (1)

experiments were justified because ultrasound has proved useful (1)

2

(c) examples

allow a wide variety of appropriate responses

publish / tell doctors / the public (1) …their evidence / results / research / data (1)

valid point (1)

appropriate example / qualification / expansion / etc (1)

carry out more research / tests (1) …to make sure / check reliability (1)

allow just ‘stop using them / ultrasonic waves’ for 1 mark only

allow using them (only) for industrial purposes for 1 mark only

2

[6]



Page 3

M2. (a) (i) 440 (sound) waves produced in one second

accept vibrations / oscillations for waves 1

(ii) 0.773 (metres)

allow 2 marks for an answer that rounds to 0.773

allow 2 marks for an answer of

allow 2 marks for an answer of 0.772

allow 1 mark for correct substitution ie 340 = 440 × λ 3

(b) (sound is) louder

do not accept the converse 1

as amplitude is larger

waves are taller is insufficient 1

higher pitch / frequency 1

as more waves are seen

reference to wavelengths alone is insufficient

waves are closer together is insufficient 1

[8]



Page 4

M3. (a) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also refer to the information in the Marking guidance, and apply a ‘best-fit’ approach to the marking.

0 marks No relevant / correct content.

Level 1 (1-2 marks) There is a basic description of either waveORWhat happens to either wave when they enter the body. However there is little other detail.

Level 2 (3-4 marks) There is either:A clear description of BOTH wavesORA clear description as to what happens to BOTH waves inside the bodyORA clear description of ONE of the waves with clear detail as to what happens to either wave inside the body.

Level 3 (5-6 marks) There is a detailed description of BOTH of the wavesANDA detailed

description as to what happens to EITHER wave inside the body.

Examples of the points made in the response:

Description of an X-ray

• X-rays are electromagnetic waves / part of the electromagnetic spectrum

do not allow a description of a property – eg X-rays travel

• X-rays are (very) high frequency (waves)

through a vacuum / at the speed of light

• X-rays are (very) high energy (waves)

• X-rays have a (very) short wavelength

• Wavelength (of X-rays) is of a similar size to (the diameter of) an atom

• X-rays are a transverse wave

correct description acceptable – oscillations / vibrations are perpendicular (at 90°) to direction of energy transfer

• X-rays are ionising radiation

Description of ultrasound

../resources/AG_BL/menus/Markingguidance.pdf



Page 5

• ultrasound has a frequency above 20 000 (hertz)

or

ultra sound is above 20 000 hertz

• ultrasound is above / beyond the human (upper) limit (of hearing)

accept ultrasound cannot be heard by humans

• ultrasound is a longitudinal wave

correct description acceptable – oscillations / vibrations (of particles) are parallel (in same direction) to direction of energy transfer

Statement(s) as to what happens to X-rays inside the human body:

• X-rays are absorbed by bone

• X-rays travel through / are transmitted by tissue / skin

Statement as to what happens to ultrasound inside body:

• ultrasound is (partially) reflected at / when it meets a boundary between two different media

• travel at different speeds through different media 6

(b) (because the X-rays) are ionising

accept a description of what ionising is 1

(they will) damage cells

instead of cell, any of these words can be used:

DNA / genes / chromosomes / nucleus

or

mutate cells / cause mutations / increase chances of mutations

or

turn cells cancerous / produce abnormal growths / produce rapidly growing cells

do not accept they can be dangerous (to human health)

do not accept damage to soft tissue

or



Page 6

kill cells 1

(c) any one from:

• removal / destruction of kidney / gall stones

• repair of damaged tissue / muscle

accept examples of repair, eg alleviating bruising, repair scar damage, ligament / tendon damage, joint inflammation

accept physiotherapy

accept curing prostate cancer or killing prostate cancer cells

• removing plaque from teeth

cleaning teeth is insufficient 1

[9]



Page 7

M4. (a) (i) perpendicular

accept correct description 1 1

(ii) light off – no / slow rotation 1

light on – fast(er) rotation

accept starts rotating

ignore references to energy transfers 1

(b) one ray drawn from wrist watch and reflected by mirror

accept solid or dashed lines 1

two rays drawn from wrist watch and reflected by mirror with i = r for both rays

judge angles by eye 1

one ray traced back behind mirror

accept solid or dashed lines 1

image in correct position

judged by eye

accept image marked where two reflected rays traced back cross behind the mirror

1

(c) cannot be formed on a screen

accept image formed behind the mirror

or

rays of light seem to come from it but do not pass through it 1

[8]



Page 8

M5.(a) the oscillation / vibration (causing the wave)

a movement causes the wave is insufficient 1

for a transverse wave is perpendicular to the direction of energy transfer

accept direction of wave travel 1

and for a longitudinal wave is parallel to the direction of energy transfer

accept direction of wave travel

if no marks awarded allow 1 mark for correctly linking perpendicular with transverse and parallel with longitudinal

the marks may be scored by the drawing of two correctly labelled diagrams

1

(b) for radio waves:

accept converse for each mark

are transverse 1

travel at speed of light / higher speed 1

have greater frequencies 1

can travel through vacuum

accept sound waves are not electromagnetic for 1 mark 1

[7]



Page 9

M6.(a) (i) 20 1

20 000

either order

accept ringed answers in box 1

(ii) (frequency) above human range

accept pitch for frequency

or

(frequency) above 20 000 (Hz)

do not accept outside human range

allow ecf from incorrect value in (a)(i) 1

(iii) any one from:

• pre-natal scanning

accept any other appropriate scanning use

do not accept pregnancy testing

• removal / destruction of kidney / gall stones • repair of damaged tissue / muscle

accept examples of repair, eg alleviating bruising, repair scar damage, ligament / tendon damage, joint inflammation

accept physiotherapy

accept curing prostate cancer or killing prostate cancer cells • removing plaque from teeth

cleaning teeth is insufficient 1

(b) 7.5 × 10−4 (m)

1.5 × 103 = 2.0 × 106 × λ gains 1 mark 2

(c) for reflected waves

must be clear whether referring to emitted or detected / reflected waves



Page 10

if not specified assume it refers to reflected wave

any two from:

• frequency decreased • wavelength increased • intensity has decreased

allow amplitude / energy has decreased allow the beam is weaker

2

[8]



Page 11

M7. (a) (sound waves) which have a frequency higher than the upper limit of hearing for humans or

a (sound) wave (of frequency) above 20 000 Hz

sound waves that cannot be heard is insufficient

a wave of frequency 20 000 Hz is insufficient 1

(b) 640

an answer of 1280 gains 2 marks

allow 2 marks for the correct substitution

ie 1600 × 0.40 provided no subsequent step

allow 2 marks for the substitution

provided no subsequent step

allow 1 mark for the substitution 1600 × 0.80 provided no subsequent step

allow 1 mark for the identification that time (boat to bed) is 0.4

3

(c) any one from:

• pre-natal scanning / imaging • imaging of a named organ (that is not surrounded by bone), eg

stomach, bladder, testicles

accept heart

do not allow brain or lungs (either of these negates a correct answer)

• Doppler scanning blood flow 1

(d) advantage

any one from:

• (images are) high quality or detailed or high resolution

clearer / better image is sufficient • (scan) produces a slice through the body • image can be viewed from any direction

allow images are (always) 3D / 360° • an image can be made of any part (inside the body)

allow whole body can be scanned • easier to diagnose or see a problem (on the image)

1

disadvantage

any one from: • (the X-rays used or scans) are ionising

allow a description of what ionising is • mutate cells or cause mutations or increase chances of mutations

allow for cells:



Page 12

DNA / genes / chromosomes / nucleus / tissue • turn cells cancerous or produce abnormal growths or produce rapidly

growing cells • kill cells

damage cells is insufficient • shielding is needed

can be dangerous (to human health) unqualified, is insufficient

1

[7]



Page 1


Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves


Difficulty Level Gold Level



Score: /31

Percentage: /100

http://www.savemyexams.co.uk/



Page 2

M1. (a) (i) 3 1

(ii) 30 000 or 10 000 × their (a)(i) correctly calculated 1

(iii) any two from:

• frequency is above 20 000 (Hz)

accept the frequency is 30 000

• frequency is above the upper limit of audible range

• upper limit of audible range equals 20 000 (Hz)

ignore reference to lower limit

• it is ultrasound/ultrasonic 2

(b) (i) wave (partially) reflected 1

at crack to produce A and end of bolt to produce B

accept at both ends of the crack 1

(ii) 0.075 (m) allow 2 marks for time = 0.0000125

allow 1 mark for time = 0.000025

answers 0.15 or 0.015 or 0.09 gain 2 marks

answers 0.18 or 0.03 gain 1 mark

the unit is not required but if given must be consistent with numerical answer for the available marks

3

[9]




Page 3

M2. (a) changes the sound wave(s)

to a varying or changing (electric) potential difference or p.d. or voltage or current or to an irregular alternating current or a.c. or transfers sound energy to electrical energy (1) mark is vibrations or pulses or of sound or in air become electrical waves

do not credit just ‘to electricity’ or ‘to a.c’ 2

(b) (i) decrease or reduce the amplitude

accept less amplitude nothing else added 1

(ii) increase the frequency or decrease wavelength

accept higher frequency nothing else added 1

[4]




Page 4

M3. (i) (partly) reflected when they hit a (boundary between two) different media or substance or tissue

accept named substances

do not accept bounce back 1

time taken for reflected wave (to return) is used to produce the image 1

(ii) any one from:

cleaning a delicate mechanism / jewellery

do not accept cleaning

welding plastics

cutting textiles

mixing emulsion paints

sonar

motion sensors (in burglar alarms)

do not accept burglar alarms

removing dental plaque

industrial quality control

breaking up kidney stones

treating injuries 1

[3]




Page 5

M4. (a) (ultrasound) waves reflected

accept ‘bounce off’ 1

at boundary / from muscle 1

(b) (i) time 1

(ii) speed of (ultrasound) waves 1

[4]




Page 6

M5. (a) any two points:

do not credit features which are true of sound in general eg longitudinal waves

• humans cannot hear ultrasound

• it has a very high frequency / pitch

do not credit just ‘has a high frequency / pitch’

• above the (upper) limit for humans / above 20 000 Hz 2

(b) (i) ultrasound / waves are reflected

...are bounced is insufficient, but

...echo is acceptable 1

Pulse A indicates / is the crack

Pulse B indicates / is the back (of the block or crack)

need to mention both A and B to get this mark 1

(ii) 90 (mm)

accept any answer in the range 88 – 92 (mm) 1

[5]




Page 7

M6. (a) (i) same frequency / period / pitch / wavelength

ignore references to amplitude 1

(ii) differences in waveform / shape / quality

accept the diagrams are not identical 1

(b) (i) 20 000 Hz / hertz

or 20 kHz / kilohertz

in both cases, if the symbol rather than the name is used, it must be correct in every detail

1

(ii) material(s) / substance(s) (through which sound travels) 1

(iii) is absorbed

accept (some) sound (energy) is transformed / transferred as heat / thermal energy

1

is transmitted

accept is refracted accept changes speed accept changes velocity

do not accept is diffracted do not accept is diffused do not accept is dissipated

1

[6]




Page 1

Electromagnetic waves

Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves

Sub-Topic Electromagnetic waves




Score: /58

Percentage: /100



Page 2

M1. (a) radio 1

(b)

award 1 mark for each correct line

if more than one line is drawn from any em wave then none of those lines gain credit

3

(c) ionising 1

[5]



Page 3

M2. (a) all three lines correct

allow 1 mark for each correct line

if more than one line goes from a device then all lines from that device are wrong

3

(b) (i) skin cancer

do not accept cancer do not accept sunburn

correct answer only 1

(ii) other factors may be involved

accept may have been in the Sun too long

accept (over)-use of sunbeds and (over)- exposure to the Sun (both) give the same symptomsaccept any other sensible factor that could lead to doubt

do not accept irrelevant answers eg may be run over by a car

do not accept killed by exposure to the Sun 1

(iii) can assess risk

answers should be in terms of assessing our own health risk

or

make your own decision

accept so you limit its use / don’t use one

do not accept so you don’t get skin cancer

do not accept so you don’t get sunburn 1

[6]



Page 4

M3. (a) vibrate / oscillate

accept a correct description

move is insufficient 1

(b) 336

allow 1 mark for correct substitution, ie 420 × 0.8(0) provided no subsequent step shown

2

[3]



Page 5

M4. (a) (i) (visible) light

accept visible 1

(ii) microwaves 1

(b) J 1

(c) (i) B 1

(ii) shorter than 1

(d) (i) To find out if using a mobile phone is harmful to health 1

(ii) any two from:

• (X has a) low(er) SAR value

“it” refers to mobile phone

accept has a low(er) rate

• (maximum) energy absorbed (by the head) is less

accept energy emitted (by phone) is less accept radiation for energy

• (if mobiles are harmful) less likely to cause harm

accept will not cause harm accept it is safer

2

[8]



Page 6

M5. (a) C 1

(b) reflection at the mirror of ray from shoe to person’s eye

may be drawn freehand 1

angle of incidence = angle of reflection

judged by eye a ruler must have been used

1

arrow to show correct direction on either incident or reflected ray

only one arrow needed but if more drawn must be no contradiction

both incident and reflected ray must be shown 1

(c) virtual 1

[5]



Page 7

M6. (a) long 1

(b) lens A 1

it is a concave / diverging lens

this mark is only gained if lens A is stated

any reference to lens material or mass of lens negates this mark

allow it will focus light onto the retina 1

(c) The refractive index of the lens material 1

(d) 4

ignore any signs

allow 1 mark for correct substitution, ie provided no subsequent step

2

(e) Cauterising open blood vessels 1

(f) 5

allow 1 mark for correct substitution, ie provided no subsequent step

2

[9]



Page 8

M7. (a) transmits

correct order 1

absorbs 1

(b) light

allow ultra violet or UV or infrared or IR or gamma 1

(c) 20

allow 1 mark for correct working, ie provided no subsequent step

2

(d) Killing cancer cells 1

[6]



Page 9

M8. (a) refraction 1

(b) towards the normal 1

(c) (i) convex 1

(ii) principal focus

accept focal point 1

(d) parallel on left 1

refracted towards the normal at first surface 1

refraction away from normal at second surface 1

passes through or heads towards principal focus 1

(e) refractive index

accept material from which it is made 1

(radius of) curvature (of the sides)

accept shape / radius



Page 10

do not accept power of lens

ignore thickness / length 1

[10]



Page 11

M9. (a) decreases

correct order only 1

increases 1

(b) (i) intensity (of transmitted light ) depends on thickness or

to enable a valid comparison or

it is a control variable

accept absorption depends on thickness

it would affect the results is insufficient

fair test is insufficient 1

(ii) transmits the least light or

absorbs the most light

accept very little light is transmitted

do not accept transmits none of the light

do not accept absorbs all of the light

any reference to heat negates this mark 1

[4]



Page 1


Mark scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves



Booklet Mark scheme 1


Score: /53

Percentage: /100



Page 2

M1. (a) (i) short sight

accept myopia 1

(ii) diverging 1

(b) light 1

(c) Marks awarded for this answer will be determined by the quality of communication as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks No relevant content

Level 1 (1–2 marks) There is a basic description of one advantage or disadvantage of using either

of the methods

Level 2 (3–4 marks) There is a description of some advantages and / or disadvantages of using both methods or

a full, detailed description of the advantages and disadvantages of using either of the methods.

Level 3 (5–6 marks) There is a clear description of the advantages and disadvantages of using both methods.

examples of the points made in the response

extra information

laser surgery

advantages:

• appearance • permanent effect



Page 3

• no glasses which need changing

disadvantages:

• risks associated with surgery • large cost • not able to drive etc straightaway • (still) might need glasses for reading

wearing glasses

advantages:

• able to function straightaway • any problems easy to sort out

disadvantages:

• easily broken • easily lost

• need changing • overall cost might be greater if several changes in vision • might eventually need two pairs of glasses

6

(d) move lens 1

closer to film 1

[11]



Page 4

M2.(a) (sound waves) which have a frequency higher than the upper limit of hearing for humans or

a (sound) wave (of frequency) above 20 000 Hz

sound waves that cannot be heard is insufficient

a wave of frequency 20 000 Hz is insufficient 1

(b) 640

an answer of 1280 gains 2 marks

allow 2 marks for the correct substitution

ie 1600 × 0.40 provided no subsequent step

allow 2 marks for the substitution

provided no subsequent step

allow 1 mark for the substitution 1600 × 0.80 provided no subsequent step

allow 1 mark for the identification that time (boat to bed) is 0.4

3

(c) any one from:

• pre-natal scanning / imaging • imaging of a named organ (that is not surrounded by bone), eg

stomach, bladder, testicles

accept heart

do not allow brain or lungs (either of these negates a correct answer)

• Doppler scanning blood flow 1

(d) advantage

any one from:

• (images are) high quality or detailed or high resolution

clearer / better image is sufficient

• (scan) produces a slice through the body • image can be viewed from any direction

allow images are (always) 3D / 360° • an image can be made of any part (inside the body)

allow whole body can be scanned • easier to diagnose or see a problem (on the image)

1

disadvantage

any one from: • (the X-rays used or scans) are ionising

allow a description of what ionising is • mutate cells or cause mutations or increase chances of mutations



Page 5

allow for cells:

DNA / genes / chromosomes / nucleus / tissue • turn cells cancerous or produce abnormal growths or produce rapidly

growing cells • kill cells

damage cells is insufficient • shielding is needed

can be dangerous (to human health) unqualified, is insufficient

1

[7]



Page 6

M3. (a) wavelength correctly shown 1

(b) (i) increased 1

decreased 1

(ii) 17-18 inclusive 1

evidence of measurement divided by 3 or mean of 3 separate measurements

1

mm

accept cm if consistent with answer 1

(c) (i) red shift 1

(ii) moving away 1

(iii) the furthest galaxies show the biggest red shift 1

(meaning that) the furthest galaxies are moving fastest 1



Page 7

(so the) Universe is expanding 1

(extrapolating backwards this suggests that) the Universe started from an initial point

1

(iv) cosmic microwave background radiation

allow CMBR 1

[13]



Page 8

M4.Level 3 (5–6 marks): A detailed and coherent plan covering all the major steps is provided. The steps in the method are logically ordered. The method would lead to the production of valid results.

A source of inaccuracy is provided.

Level 2 (3–4 marks):

The bulk of a method is described with mostly relevant detail. The method may not be in a completely logical sequence and may be missing some detail.


Simple statements are made. The response may lack a logical structure and would not lead to the production of valid results.

0 marks: No relevant content.

Indicative content

place a glass block on a piece of paper

draw around the glass block and then remove from the paper

draw a line at 90° to one side of the block (the normal)

use a protractor to measure and then draw a line at an angle of 20° to the normal

replace the glass block

using a ray box and slit point the ray of light down the drawn line

mark the ray of light emerging from the block

remove the block and draw in the refracted ray

measure the angle of refraction with a protractor

repeat the procedure for a range of values of the angle of incidence

possible source of inaccuracy

the width of the light ray

which makes it difficult to judge where the centre of the ray is [6]



Page 9

M5.(a) Level 3 (5–6 marks): A detailed and coherent plan covering all the major steps is provided. The steps in the method are logically ordered. The method would lead to the production of valid results.

A source of inaccuracy is provided.


The bulk of a method is described with mostly relevant detail. The method may not be in a completely logical sequence and may be missing some detail.


Simple statements are made. The response may lack a logical structure and would not lead to the production of valid results.

0 marks:

No relevant content.

Indicative content

place a glass block on a piece of paper

draw around the glass block and then remove from the paper

draw a line at 90° to one side of the block (the normal)

use a protractor to measure and then draw a line at an angle of 20° to the normal

replace the glass block

using a ray box and slit point the ray of light down the drawn line

mark the ray of light emerging from the block

remove the block and draw in the refracted ray

measure the angle of refraction with a protractor

repeat the procedure for a range of values of the angle of incidence

possible source of inaccuracy

the width of the light ray

which makes it difficult to judge where the centre of the ray is 6

(b) velocity / speed of the light decreases

allow velocity / speed of the light changes 1

[7]



Page 10

M6.(a) magnification = 1

dividing by an object height of 1 cm gives the same (numerical) value 1

(b) accept anything practical that would work eg:

use a taller object

use a (travelling) microscope

attach a scale to the screen and use a magnifying glass 1

(c) both points plotted correctly 1

correct line of best fit drawn

a curve passing through all points (within ½ square), judge by eye

1

(d) values of 1.4 and 0.6 extracted from the graph 1

2.33 times bigger

accept any number between 2.3 and 2.5 inclusive 1

(e) by dividing the distance between the lens and the image by the distance between the lens and the object

1



Page 11

at least one correct calculation and comparison eg 100÷25 = 4 which is the same as the measured magnification

1

[9]



Page 1


Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves





Score: /59

Percentage: /100




Page 2


• travel (at same speed) through a vacuum / space

do not accept air for vacuum

• transverse

• transfer energy

• can be reflected

• can be refracted

• can be diffracted

• can be absorbed

• travel in straight lines 2

(b) can pass through the ionosphere

accept atmosphere for ionosphere

do not accept air for ionosphere

accept travel in straight lines

accept not refracted / reflected / absorbed by the ionosphere 1

(c) v = f λ

1.2 × 106 / 1200 000

allow 1 mark for correct substitution ie 3.0 × 108 = f × 2.5 × 102

2

hertz / Hz

do not accept hz or HZ

accept kHz or MHz

answers 1.2 MHz or 1200 kHz gain all 3 marks

for full credit the unit and numerical value must be consistent 1

[6]




Page 3

M2. (a) (i) gamma

accept correct symbol 1

(ii) any one from:

• (ultraviolet has a) higher frequency

ultraviolet cannot be seen is insufficient

• (ultraviolet has a) greater energy

• (ultraviolet has a) shorter wavelength

ignore ultraviolet causes cancer etc 1

(b) 1.2 × 107 / 12 000 000

allow 1 mark for correct substitution, ie 3 × 108 = f × 25 2

hertz / Hz / kHz / MHz

do not accept hz or HZ

answers 12 000 kHz or 12 MHz gain 3 marks

for full credit the numerical answer and unit must be consistent

1

(c) (i) away (from each other)

accept away (from the Earth) accept receding

1

(ii) distance (from the Earth)

accept how far away (it is) 1




Page 4

speed galaxy is moving 1

(iii) (Universe is) expanding 1

[9]




Page 5

M3. (a) (i) two correct rays drawn

1 mark for each correct ray

• ray parallel to axis from top of object and refracted through focus and traced back beyond object

• ray through centre of lens and traced back beyond object

• ray joining top of object to focus on left of lens taken to the lens refracted parallel to axis and traced back parallel to axis beyond object

2

an arrow showing the position and correct orientation of the image for their rays

to gain this mark, the arrow must go from the intersection of the traced-back rays to the axis and the image must be on the same side of the lens as the object and above the axis

1

(ii) (x) 3.0

accept 3.0 to 3.5 inclusive or

correctly calculated

allow 1 mark for correct substitution into equation using their figures

ignore any units 2




Page 6

(b) any two from:

in a camera the image is:

• real not virtual

• inverted and not upright

accept upside down for inverted

• diminished and not magnified

accept smaller and bigger accept converse answers but it must be clear the direction of the comparison

both parts of each marking point are required 2

[7]




Page 7

M4. (a) (i) to check rise in temperature (of other thermometers) was due to the (different wavelengths of) light

accept as a control / comparison

to measure room temperature is insufficient 1

(ii) any two from three:

• different colours produce different heating effects / (rises in) temperatures

• red light produces the greatest heating effect / (rise in) temperature

or

• violet produces the least heating effect / (rise in) temperature

• all colours produce a greater heating effect than outside the spectrum

an answer

the longer the wavelength the greater the (rise in) temperature

or

the lower the frequency the greater the (rise in) temperature gains both marks

2

(b) move a thermometer into the infrared region / just beyond the red light

allow use an infrared camera / infrared sensor 1

the temperature increases beyond 24(°C)

accept temperature higher than for the red light 1

(c) v = f × λ

9.4 × 10-6

accept 9.375 × 10-6 or 9.38 × 10-6

or

0.0000094




Page 8

accept 0.000009375

or 0.00000938

allow 1 mark for correct substitution ie 3 × 108 = 3.2 × 1013 × λ

2

(d) at night the surroundings are cooler

accept at night the air is colder

there is no heat from the Sun is insufficient

or

at night there is a greater temperature difference between people and surroundings 1

(so surroundings) emit less infrared (than in daytime)

accept camera detects a greater contrast

or

gives larger difference in infrared emitted (between people and surroundings) 1

[9]




Page 9

M5.(a) (i) frequency 1

wavelength 1

(ii) 10-15 to 104

1

(b) 2.0 × 105

correct substitution of 3.0 × 108 / 1500 gains 1 mark

2

Hz 1

(c) (i) (skin) burns 1

(ii) skin cancer / blindness 1

(d) (i) any one from:

• (detecting) bone fractures • (detecting) dental problems • treating cancer

1

(ii) any one from:

• affect photographic film • absorbed by bone • transmitted by soft tissue




Page 10

• kill (cancer) cells

answer must link to answer given in (d)(i) 1

(iii) 9 / 36 = 0.25 0.5 / 2 = 0.25 4 / 16 = 0.25

accept:

36 / 9 = 4

2 / 0.5 = 4

16 / 4 = 4 2

conclusion based on calculation

two calculations correct with a valid conclusion scores 2 marks

one correct calculation of k scores 1 mark 1

[13]




Page 11

M6. (a) C or 0.18 mm 1

(b) 0.6 (m)

allow 1 mark for correct substitution and/or transformation or 1 mark for changing frequency to Hz answer 600 gains 1 mark

2

(c) creates an alternating current

accept ‘ac’ for alternating currentaccept alternating voltage 1

with the same frequency as the radio wave

accept signal for radio wave

accept it gets hotter for 1 mark provided no other marks scored

1

(d) X-rays cannot penetrate the atmosphere

accept atmosphere stops X-rays

do not accept atmosphere in the way

or

X-rays are absorbed (by the atmosphere) before reaching Earth

ignore explanations 1

[6]

M7.(for both fibres) increasing the wavelength of light decreases and then increases the percentage / amount of light transmitted

accept for 1 mark: (for both fibres) increasing the wavelength (of light) to 5 (x 10-7 metres), decreases the (percentage) transmission

1

(for both fibres) the minimum transmission happens at 5 (x 10-7 metres) or

maximum transmission occurs at 6.5 (x 10-7 metres)

accept for a further 1 mark:




Page 12

(for both fibres) increasing the wavelength of the light from 5 (x 10-7 metres) increases the amount of light transmitted

increasing wavelength (of light), decreases the percentage transmitted is insufficient on its own

1

the shorter fibre transmits a greater percentage of light (at the same wavelength)

accept for 1 mark: Any statement that correctly processes data to compare the fibres

1

[3]




Page 13

M8. (a) 10–15 metres to 104 metres 1

(b) (i) any one from:

• (TV / video / DVD) remote controls

mobile phones is insufficient

• (short range) data transmission

accept specific example, eg linking computer peripherals

• optical fibre (signals)

do not accept Bluetooth 1

(ii) 0.17

an answer 17 cm gains 3 marks

an answer given to more than 2 significant figures that rounds to

0.17 gains 2 marks

allow 1 mark for correct substitution, ie 3 × 108 = 1.8 × 109 × λ 3

(c) (maybe) other factors involved

accept a named ‘sensible’ factor, eg higher stress / sedentary lifestyle / overweight / smoking more / diet / hot office / age

not testing enough people is insufficient

unreliable data is insufficient 1

[6]




Page 1

Black Body Radiation

Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves

Sub-Topic Black Body Radiation




Score: /34

Percentage: /100



Page 2

M1. (a) (i) 25 (%)

do not accept ¼ 1

(ii) increases 1

(b) tick ( ) in top and bottom box

both required 1

(c) SHINY surfaces are good reflectors of infra-red radiation

accept white for shiny

or black surfaces are POOR reflectors of infra-red radiation

accept bad for poor accept insertion of ‘not’ before ‘good’ in statement

or black surfaces are good EMITTERS of infra-red radiation

or black surfaces are good ABSORBERS of infra red radiation 1

[4]

-



Page 3

M2. (a) to reflect (the infrared)

accept (shiny surfaces) are good reflectors

ignore reference to incorrect type of wave 1

(b) black 1

best absorber (of infrared)

answer should be comparativeblack absorbs (infrared) is insufficient

accept good absorber (of infrared)

ignore reference to emitter ignore attracts heatignore reference to conduction

1

(c) to reduce energy loss

accept to stop energy loss accept heat for energy accept to stop / reduce convection

orso temperature of water increases faster

accept to heat water faster accept cooks food faster

orreduces loss of water (by evaporation) 1

(d) 672 000

allow 1 mark for correct substitution, ie 2 × 4200 × 80 provided no subsequent step shown

2

[6]



Page 4

M3. absorber 1

reflector 1

emitter 1

[3]



Page 5

M4. (a) (i) The volume of boiling water. 1

(ii) any one from:

• (more) precise

do not accept better (reading)

• accurate

• reliable

do not accept thermometer is unreliable

• removes human / reading error

accept easier to read accept take temperature more frequently

1

(b) B

marks are for the explanation

temperature falls faster

this mark point cannot score if A chosen 1

because black is a better / good emitter

ignore reference to better absorber accept for both marks an answer in terms of why A is the white can

1

(c) (i) faster than 1

(ii) darker / black surfaces absorb heat faster

accept black is a better / good absorber

dark surfaces attract heat negates this mark 1



Page 6

(iii) air is a bad / poor conductororair is a good insulator

accept air is an insulator 1

[7]



Page 7

M5. (a) the bigger the surface area, the faster the water cools down / temperature falls

answers must imply rate

accept heat for temperature provided rate is implied

do not accept cools down more unless qualified 1

(b) any two from:

the ears:

• have large surface / area

not just has large ears

• radiate heat

accept loses heat, but does not score if the reason given for heat loss is wrong

• keep blood cooler 2

(c) (i) radiation 1

(ii) conduction 1

[5]



Page 8

M6. (a) (i) convection 1

(ii) conduction 1

(b) (i) 2 1

black is the best absorber (of thermal energy / heat)

accept black is the best emitter (of thermal energy / heat)

note that a comparative is needed (eg better or best) 1

(ii) the colour of the metal plates 1

(iii) any one from:

• more precise / accurate / reliable

do not accept better reading

do not accept thermometer is unreliable

• can measure continuously

• take many readings in a small time

• removes (human) reading error

accept easier to read

• can compare / draw graphs automatically

• records data automatically 1

(c) (i) radiation

accept radiates

accept infra red (IR) waves



Page 9

do not accept heat waves 1

(ii) to reflect (heat away from the fire fighter)

accept it reflects

accept it is a poor absorber (of thermal radiation / heat)

do not accept deflect / bounce for reflect 1

(d) N

the mark is for the reason which does not score if M is chosen

transfers / absorbs less heatorgives smallest increase in temperature

accept will keep fire fighters cooler

accept N is cooler (after 15 minutes)

an answer N goes up to 52°C and M goes up to 100°C is insufficient

1

[9]



Page 1

Black body radiation

Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves

Sub-Topic Black body radiation


Booklet Mark scheme 1


Score: /54

Percentage: /100



Page 2


• black is a good emitter of (infrared radiation)

accept heat for radiation

ignore reference to absorbing radiation

• large surface (area)

• matt surfaces are better emitters (than shiny surfaces)

accept matt surfaces are good emitters

ignore reference to good conductor 2

(b) 90% or 0.9(0)

allow 1 mark for correct substitution, ie

provided no subsequent step shown

an answer of 90 scores 1 mark

an answer of 90 / 0.90 with a unit scores 1 mark 2

(c) (producing) light

allow (producing) sound 1

(d) any two from:

• wood is renewable

accept wood grows again / quickly accept wood can be replanted

• (using wood) conserves fossil fuels

accept doesn’t use fossil fuels

• wood is carbon neutral

accept a description



Page 3

cheaper / saves money is insufficient 2

(e) E = m × c × θ

2 550 000

allow 1 mark for correct substitution ie 100 × 510 × 50 provided no subsequent step shown

answers of 1 020 000, 3 570 000 gain 1 mark 2

joules /J

accept kJ / MJ

do not accept j

for full credit the unit and numerical answer must be consistent

1

[10]



Page 4

M2. (a) (i) radiation

ignore thermal / infrared 1

(ii) black is a better / good absorber (of heat / radiation)

ignore reference to black being a good emitter

black absorbs heat is insufficient

do not accept black attracts / absorbs the Sun

do not accept black attracts heat 1

(so) temperature rises faster

must be an indication of heating up quicker orwhite is a worse / poor absorber (of heat / radiation) (1)

accept white is a better / good reflector (of heat / radiation)

(so if white faces) temperature would rise slower (1)

ignore any reference to light 1

(b) (i) 1.2 (hours) or 1 hour 12 minutes

no tolerance 1

(ii) increases (rapidly at first then increases at a slower rate)

do not accept increases at a steady rate 1

(c) (i) any two from:

• (fill with) same mass / volume / amount of water

• same level of (sun)light / sunshine

accept same heat / light source

accept same place

• outside for the same (length of) time

• outside at same time (of day / year)



Page 5

• initial water temperature

• the side of the bag facing the Sun

do not accept any factors to do with the construction of plastic bags eg thickness

2

(ii) curved line drawn above given line

both lines must start from the same point

ignore if continues beyond one hour or levels off after 1 hour

do not accept a straight line 1

[8]



Page 6

M3. (a) dark matt 1

light shiny 1

(b) B A C 1

biggest temperature difference (80 °C)

dependent on first mark 1

(c) (i) (the can that is) dark matt 1

best absorber (of infrared radiation) 1

(ii) any three from:

• same area / shape of can • surrounding temperature is the same for all cans • same surface underneath cans • same position in the room

3

(d) fox A

smaller ears 1

thicker fur 1



Page 7

these minimise energy transfer

dependent on first 2 marks 1

[12]



Page 8

M4. (a) (black) is a good absorber of (infrared) radiation 1

(b) (i) amount of energy required to change (the state of a substance) from solid to liquid (with no change in temperature)

melt is insufficient 1

unit mass / 1kg 1

(ii) 5.1 × 106 (J)

accept 5 x 106

allow 1 mark for correct substitution ie E = 15 × 3.4 × 105

2

(c) (i) mass of ice

allow volume / weight / amount / quantity of ice 1

(ii) to distribute the salt throughout the ice 1

to keep all the ice at the same temperature 1

(iii) melting point decreases as the mass of salt is increased

allow concentration for mass

accept negative correlation

do not accept inversely proportional 1

(d) 60 000 (J)

accept 60 KJ



Page 9

allow 2 marks for correct substitution ie E = 500 × 2.0 × 60

allow 2 marks for an answer of 1000 or 60

allow 1 mark for correct substitution ie

E = 500 × 2.0 or 0.50 × 2.0 × 60

allow 1 mark for an answer of 1 3

(e) Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.

0 marks

No relevant content

Level 1 (1–2 marks) There is an attempt at a description of some advantages or disadvantages.

Level 2 (3–4 marks) There is a basic description of some advantages and / or disadvantages for some of the methods

Level 3 (5–6 marks)

There is a clear description of the advantages and disadvantages of all the methods.

examples of the points made in the response

extra information

energy storage

advantages:

• no fuel costs • no environmental effects

disadvantages:

• expensive to set up and maintain • need to dig deep under road • dependent on (summer) weather • digging up earth and disrupting habitats

salt spreading

advantages:

• easily available • cheap

disadvantages:



Page 10

• can damage trees / plants / drinking water / cars • needs to be cleaned away

undersoil heating

advantages:

• not dependent on weather • can be switched on and off

disadvantages:

• costly • bad for environment

6

[18]



Page 11

M5. (a) infrared / IR

correct answer only 1

(b) any two from:

• increase the power / watts

allow increase the temperature of the oven or make the oven hotter

• decrease the speed

allow leave the biscuits in for longer • put biscuits through again

increase radiation is insufficient

ignore changes to the design of the oven 2

(c) (inside) surface is a (good) reflector or poor absorber (of IR)

Ignore bounce for reflect

surface is a (good) reflector of light does not score

surface is a (good) reflector of light and infrared / heat does score

1

(and) outside surface is poor emitter (of IR) 1

(so) increases the energy reaching the biscuits

allow reduces energy loss or makes oven more efficient

do not accept no energy losses

keeps oven hotter is insufficient 1

[6]



Page 1

Black body Radiation

Mark Scheme 1

Level GCSE (9-1)

Subject Physics

Exam Board AQA

Topic 4.6 Waves

Sub-Topic Black body Radiation




Score: /29

Percentage: /100




Page 2

M1. (a) (i) to check rise in temperature (of other thermometers) was due to the (different wavelengths of) light

accept as a control / comparison

to measure room temperature is insufficient 1

(ii) any two from three:

• different colours produce different heating effects / (rises in) temperatures

• red light produces the greatest heating effect / (rise in) temperature

or

• violet produces the least heating effect / (rise in) temperature

• all colours produce a greater heating effect than outside the spectrum

an answer

the longer the wavelength the greater the (rise in) temperature

or

the lower the frequency the greater the (rise in) temperature gains both marks

2

(b) move a thermometer into the infrared region / just beyond the red light

allow use an infrared camera / infrared sensor 1

the temperature increases beyond 24(°C)

accept temperature higher than for the red light 1

(c) v = f × λ

9.4 × 10-6

accept 9.375 × 10-6 or 9.38 × 10-6

or

0.0000094

accept 0.000009375




Page 3

or 0.00000938

allow 1 mark for correct substitution ie 3 × 108 = 3.2 × 1013 × λ

2

(d) at night the surroundings are cooler

accept at night the air is colder

there is no heat from the Sun is insufficient

or

at night there is a greater temperature difference between people and surroundings 1

(so surroundings) emit less infrared (than in daytime)

accept camera detects a greater contrast

or

gives larger difference in infrared emitted (between people and surroundings) 1

[9]




Page 4

M2. (a) convection air is heated by the burner / particles gain energy air expands / particles move about more / particles move faster air becomes less dense / particles are more spread out air rises / particles rise - not heat rises air from C moves into the heater / particles from C move into the heater to replace it / them

any four for 1 mark each 4

(b) (i) radiation

for one mark 1

(ii) black surface radiates / emits well (allow absorbs and emits well) (allow comparison with shiny / white surfaces)

large surface area needed high temperature (of the lumps)

any one for 1 mark 1

[6]




Page 5

M3. (a) ions / electrons gain (kinetic) energy

accept atom / particles / molecules for ion accept ions vibrate faster accept ions vibrate with a bigger amplitude accept ions vibrate more do not accept ions move faster

1

(free) electrons transfer energy by collision with ions or energy transferred by collisions between vibrating ions

1

(b) move faster or take up more space

do not accept start to move / vibrate 1

(warmer) water expands or becomes less dense (than cooler water)

do not accept answers in terms of particles expanding 1

warm water rises (through colder water) or colder water falls to take its place 1

(c) transfer of energy by waves / infrared (radiation)

accept rays for waves

do not accept transfer of energy by electromagnetic waves

ignore reference to heat 1

[6]




Page 6

M4. (a) conduction

do not accept conductor 1

(b) the freezer

both parts needed

greater temperature difference (between freezer and room)

do not accept because it is the coldest 1

(c) any two from:

• poor absorber of heat / radiation

accept does not absorb heat poor emitter of heat / radiation is neutral

• reflects heat / radiation (from room away from fridge-freezer)

• reduces heat transfer into the fridge-freezer

• reduces power consumption of fridge-freezer

do not accept it is a bad conductor / good insulator 2

[4]




Page 7

M5. (i) this mark only scores if a correct pair is chosen and a correct reason given

A and C

both required and none other orB and D

both required and none other

only one (independent) variableordifferent shapes but the same colour

accept only the shape changes 1

(ii) B radiates heat faster

converse answer in terms of A gains full marks 1

orB is a better emitter (of heat)

but B has a smaller (surface) areaorB has a smaller (surface) area: volume ratio

allow 2 marks for both lose the same quantity / amount of heat in the same time

or both have same rate of heat loss

allow 1 mark for both lose the same quantity / amount of heat

1

(iii) any one from:

• transfer a lot of heat (too rapidly)

• water temperature drops too rapidly

accept (significantly) more heat will be lost from the first radiator

• water too cold for the next radiator

mention of absorption of heat negates mark 1

[4]


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