Both Required, Either Order

Hinchley Wood School

M1.(a) (i)J and L

both required, either order

(ii)K

(iii)L

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

(b) transmitter

detector

computer

all three in correct order

allow 1 mark for one correct

[6]

M2.Quality of written communication

award for a sensible sequence of two points

X-rays do not go through lead

accept lead protects them from the X-rays
accept not exposed to X-rays

lead stops / reduces risk of X-rays harming / damaging / killing (persons) cells

accept X-rays (may) cause cancer

accept organs for cell
do not accept references to electric shock
do not accept stops bones of people showing on X-ray
answers involving the horse wearing an apron are incorrect

references to gamma rays are incorrect

[3]

M3. (i) X-rays or gamma rays

for 1 mark

(ii) passes through flesh;
stopped by bone/absorbed

for 1 mark each

[3]

M4. (a) 10 600 (Hz)

accept 10.6 kHz

(b) 3000 (Hz)

allow 1 mark for a line drawn to show greatest movement(allow only if frequency is between 2800 and 3200)

accept other indication of correctly using the graph

no marks for just the ticked box

reasons can score even if yes is ticked

(human hearing) range is 20 – 20 000 (Hz)

accept (most) people hear up to 20 000 (Hz) / 20 kHz

any one from:

•range on graph is within this range

•range on graph starts after 20 Hz

•range on graph is from to 200 – 10 600 (Hz)

•range on graph finishes before 20 000 Hz

(d) reliability

this answer only

(e) only 1 variable affects dependent variable / size of movement

accept ‘results’ for ‘size of movement’

orthere is only one independent variable

fair test is insufficient

do not accept to control the experiment

orto be able to compare (effect of different frequencies)

[7]

M5. (a) X-rays are ionising
or
X-rays kill / damage cells

accept cause cancer

any stray X-rays are absorbed by screen

which reduces the radiation dose to the radiographer

(b) medical records / X-ray records

of people with cancer

therefore the image can be observed from different directions

[7]

M6.idea that X-rays cause mutations

gains 1 mark

but X-rays can cause/increase chance of mutations

gains 2 marks

mutations usually harmful/produce abnormal growth
serious effect on growing foetus/rapidly growing cells

each for 1 mark

[4]

M7.(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

• ultrasound has a frequency above 20 000 (hertz)

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

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

accept a description of what ionising is

(they will) damage cells

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

DNA / genes / chromosomes / nucleus

mutate cells / cause mutations / increase chances of mutations

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

kill cells

• 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

[9]

M8. (a) (i) same frequency / period / pitch / wavelength

ignore references to amplitude

(ii) differences in waveform / shape / quality

accept the diagrams are not identical

(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

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

(iii) is absorbed

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

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

[6]

M9. (a) any two from:

•amplitude decreasing

accept siren / sound getting quieter
do not accept sound decreases

•wavelength increasing

•frequency decreasing

accept pitch decreasing
ignore reference to transverse wave
ignore reference to speed

contradictory statements within each point lose the mark

Quality of written communication

all emboldened terms in candidate’s answer used correctly

(b) (i) ultrasound or ultrasonic

(ii) wave speed = frequency × wavelength

accept speed / velocity for wave speed

accept v = f λ
do not accept w for λ
do not accept s for v
accept

provided subsequent calculation
shows a correct method

(iii) 339.2 or 340 or 339

allow 1 mark for using 212 000
allow 1 mark for correct substitution

an answer of 0.3392 or 0.34 or 0.339 gains 1 mark only
award full credit for a correct numerical answer with the unit changed to km/s

[8]

M10. (a) (ultrasound) waves reflected

accept ‘bounce off’

at boundary / from muscle

(b) (i) time

(ii) speed of (ultrasound) waves

[4]

M11. (a) sound with a frequency above audible

do not accept answer in terms of λ

do not accept sound which cannot be heard unless obvious from context

accept above 20 kHz

(b) (i) to show detail or to give a clear image/picture

accept the generators or transducers can be small

accept so the beam does not spread out/beam in focus

not ‘good picture’

(ii) (much) smaller wavelength

allow higher frequency/pitch

(iii) no damage to living cells (provided low power)

accept the converse

accept no damage to baby or not dangerous to baby

(iv) any two forms

sex

stage of development

or specific examples

abnormalities

general health

potential problems (at birth)

accept specific examples e.g. umbilical cord around neck

size of head

accept multiple births

[6]

M12.(a) (i)3

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

(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

(b)(i) wave (partially) reflected

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

accept at both ends of the crack

(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

[9]

E1.(a) (i) Just over 72% of candidates recognised which two traces had the same amplitude.

(ii) Nearly 83% of candidates knew which trace represented the loudest sound.

(iii) A large number of candidates incorrectly indentified the ultrasound as trace M with the reason ‘because it can’t be heard’. Of the 53% of candidates who correctly identified trace L many went on to describe characteristics of ultrasound rather than relating their answer to the traces shown in the question and therefore failed to gain the second mark.

(b)This question was well answered with 69% of candidates gaining both marks. Only 8.5% of candidates failed to score at least one mark.

E2. Providing of a copy of the Electromagnetic Spectrum enabled many candidates to correctly identify the types of waves utilised in various applications, but few candidates chose radio as the answer to part (a)(i). In part (b) few candidates realised the commonality of the speed of these waves.

E3.Generally well answered.

E4. (a) Many candidates lost marks by not being careful enough in taking readings from the graph. A significant number of candidates gave 10 300 instead of 10 600.

(b) Candidates had greater success in answering this part question. A common error however was to misread the scale and give an answer of 2500.

(c) A considerable number of candidates misread the question as ‘Can most people hear the full range of sound the loudspeaker produces?’. The answers given suggested some confusion between loudness and frequency and many answers were very vague such that no marks could be awarded.

(d) The majority of candidates understood that this procedure improves the reliability.

(e) Most candidates only answered in terms of making it a ‘fair test’ which was insufficient.

E6. Though the majority of candidates gained most of the credit for this question, relatively few candidates gained the mark available for pointing out that the rapid growth/cell division of the developing baby would make it especially prone to detrimental mutations. (Some candidates did, however, make a similar point with respect to the mother’s reproductive cells, ie. answered a rather different question.)

E7.(a) Very few candidates obtained level 3 (5 or 6 marks), about half obtained level 1 (1 or 2 marks). In general, the responses regarding X-rays were answered in more detail than ultrasound. Many candidates were able to describe what the wave did, but failed to give accurate or detailed descriptions of the waves. Wavelength and frequency descriptions were often muddled. In many wrong responses, candidates failed to answer the question posed, often just appearing to write down any facts they had learned.

(b) Almost half of the candidates failed to gain any mark on this question. Often wrong responses detailed how X-rays affected the human body, organs or tissues; rather than damage at a cellular level.

(c) Less than one third of candidates could give a medical treatment using ultrasound. The most common correct response related to the treatment or removal of kidney stones. Many candidates with incorrect responses failed to note that the question asked for ‘other than imaging’ and stated scans of a fetus as their answer.

E8. (a) (i) The majority of candidates scored a mark.

(ii) Most candidates were able to explain that the diagrams represent different musical instruments because there are differences in detail between their shapes.

(b) (i) Most candidates knew the numerical value of the required frequency but some of them lost the mark because of careless use of units as illustrated by ‘20 000 kHz’.

(ii) In part (b)(ii) most candidates understood the meaning of the word ‘media’ in the context of the short passage on ultrasound.

(iii) Most candidates were able to obtain one mark out of the two for stating that some of the ultrasound is absorbed.

E9. In part (a) few candidates were able to score full marks. The majority of candidates showed a poor understanding of amplitude, frequency and wavelength. Many answers contained contradictions, such as ‘frequency increases and pitch decreases’. Part (b)(i) was disappointing with many candidates unable to remember the word ultrasound or ultrasonic. The equation in part (b)(ii) was often correct but the subsequent calculation in part (b)(iii) was rarely correct, a common error being to leave the frequency in kHz.

E10. Ultrasound still tends to confuse most candidates.

(a) Those who read and applied the information in the introduction to the question, scored best. These candidates realised that some ultrasound waves would be reflected from the layer of muscle underneath the fat. Weaker candidates ignored this information and answered in terms of ante-natal pictures.

(b) Many realised that the oscilloscope measures time, but only the most able candidates realised that wave-speed was needed in (ii).

E11.Foundation Tier

Part (a) was poorly answered with very few candidates being able to give a reasonable definition of ultrasound. In part (b) most candidates thought that a wider beam would cause problems for both the mother and baby. Few considered that a narrow beam would give more detail. Most candidates were able to give sensible answers in part (b)(iv).

Higher tier

Part (a) was answered poorly with very few candidates being able to give a reasonable definition of ultrasound. In part (b) most candidates thought that a wider beam would cause problems for both the mother and baby. Few considered that a narrow beam would give more detail. Most candidates were able to give sensible answers in both part (b)(iii) and part (b)(iv).

E12.(a) (i) A disappointing response to this part question with only just over 64% of candidates being able to count the number of waves shown correctly.

(ii) With the benefit of ‘error carried forward’ just over 80% of candidates were able to score this mark.

(iii) This was generally well answered with only a small proportion of candidates (9%) failing to score any marks. Most candidates knew the range of human hearing.

(b)(i) many candidates failed to score marks because correct terminology was not used: instead of reflection, words used included ‘detected’, ‘repulsed’, ‘bounced back’, ‘echoed’ and ‘transmitted’. There was some confusion between reflection and refraction. Misconceptions included that both pulses A and B resulted from cracks and that from A to B was the extent of the crack.

(ii) Very few candidates (4%) scored all three marks. However many candidates scored some marks by showing a correct method using an incorrect distance. Others gained a mark for showing a method but forgetting to include the reflected distance. There was some confusion over the appropriate unit to give the numerical answer.

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