THE FINAL VERSION_ AQA A-LEVEL PHYSICS 74081-2_Paper 2_A-LEVEL_Mark scheme June 2022 _, Exams of Physics

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AQA A-LEVEL PHYSICS 7408/

Paper 1 Mark scheme June 2022

Version: 1.0 Final

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A-LEVEL

PHYSICS

Paper 2

Mark scheme

June 2022

Version: 1.0 Final

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE 2

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE

Physics - Mark scheme instructions to examiners

1. General

The mark scheme for each question shows:

• the marks available for each part of the question
• the total marks available for the question
• the typical answer or answers which are expected
• extra information to help the Examiner make his or her judgement and help to delineate

what is acceptable or not worthy of credit or, in discursive answers, to give an overview

of the area in which a mark or marks may be awarded.

The extra information is aligned to the appropriate answer in the left-hand part of the

mark scheme and should only be applied to that item in the mark scheme.

At the beginning of a part of a question a reminder may be given, for example: where

consequential marking needs to be considered in a calculation; or the answer may be on the

diagram or at a different place on the script.

In general the right-hand side of the mark scheme is there to provide those extra details

which confuse the main part of the mark scheme yet may be helpful in ensuring that

marking is straightforward and consistent.

2. Emboldening

2.1 In a list of acceptable answers where more than one mark is available ‘any two

from’ is used, with the number of marks emboldened. Each of the following bullet

points is a potential mark.

2.2 A bold and is used to indicate that both parts of the answer are required to award the

mark.

2.3 Alternative answers acceptable for a mark are indicated by the use of or. Different

terms in the mark scheme are shown by a / ; eg allow smooth / free movement.

3. Marking points

3.1 Marking of lists

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE

However, if the answer is incorrect, mark(s) can usually be gained by correct substitution

/ working and this is shown in the ‘extra information’ column or by each stage of a longer

calculation.

A calculation must be followed through to answer in decimal form. An answer in surd

form is never acceptable for the final (evaluation) mark in a calculation and will therefore

generally be denied one mark.

3.3 Interpretation of ‘it’

Answers using the word ‘it’ should be given credit only if it is clear that the ‘it’ refers

to the correct subject.

3.4 Errors carried forward, consequential marking and arithmetic errors

Allowances for errors carried forward are likely to be restricted to calculation questions and

should be shown by the abbreviation ECF or conseq in the marking scheme.

An arithmetic error should be penalised for one mark only unless otherwise amplified

in the marking scheme. Arithmetic errors may arise from a slip in a calculation or from

an incorrect transfer of a numerical value from data given in a question.

3.5 Phonetic spelling

The phonetic spelling of correct scientific terminology should be credited (eg fizix)

unless there is a possible confusion (eg defraction/refraction) with another technical

term.

3.6 Brackets

(…..) are used to indicate information which is not essential for the mark to be awarded but

is included to help the examiner identify the sense of the answer required.

3.7 Ignore / Insufficient / Do not allow

‘Ignore’ or ‘insufficient’ is used when the information given is irrelevant to the question or

not enough to gain the marking point. Any further correct amplification could gain the

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE

working can gain the sf mark. For a question beginning with the command word ‘Show

that…’, the answer should be quoted to one more sf than the sf quoted in the question eg

‘Show that X is equal to about 2.1 cm’ –

4

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE

highest level of the mark scheme.

An answer which contains nothing of relevance to the question must be awarded no marks.

5

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE 2022 Want to earn $103 per month?

Question Answers Additional comments/Guidelines Mark AO

01.1 Combining and making use of Q = Pt and Q =

1 numerical^ errors^ are^ ignored^ for^ this

mark. Provided the temperature

difference is correct then subsequent

changes that involve 273 0 C can be

ignored. ( 125 − 20 )

2 t = (1.2 × 450)^ 2100

No ecf for the second mark but correct

answer gains both marks

Condone use of c water for c metal.

2 2 x AO

mc 𝜃 equations without the need to make t the subject. 1 t = 27 (s) (^2)

6

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE Want to earn $103 per month? Calculatio^2 n^0 o^2 f^2 time taken to obtain 60 g of steam

= 75.3 s.

3 So claim is not true.

0.048 kg min– 1 is smaller than 60 g min– 1

OR

0.00080 kg s– 1 = 48 g min– 1 is smaller than 60 g

min– 1

OR

2.6 × 103 W is greater (than 2.1 kW / power available) OR time to generate 60 g of steam is too long.

(The most common ecf will be to leave out the raising of the water temperature

= 0.055 kg min–1, or m = 0.00091 kg s–1 or P = 2.3 × 103 W)

Total 5

8

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE Want to earn $103 per month?

Question Answers Additional comments/Guidelines Mark AO

02.1 Any two from

• Volume of molecules/particles is

negligible/small compared to the volume

of the container

• Collision time is negligible/small compared to

the time between collisions

• Collisions are elastic or kinetic energy is conserved
• There are negligible/no forces

between molecules/particles except

during collisions

Reference to the volume occupied by the

gas must be clear for the first point. So

‘volume of gas’ is not enough.

Condone missing reference to “except

during collisions” in bullet 4.

Condone “Newtonian mechanics apply”

2 2 x AO

9

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE 1 Want to earn $103 per month? 2 𝑚𝑚

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE Want to earn $103 per month? amount of gas = 29 (mol) 3 (28.6 mol)

3 no ecf, correct answer only

If no other marks are awarded, award one mark:

for an unsupported final answer of 1.7 x 10 25 which is the number of molecule

OR

for converting a number of molecules into

moles using their𝑚= 𝑚

𝑚𝑚 1

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE Want to earn $103 per month?

Question Answers Additional comments/Guidelines Mark AO

MAX 2 from:

the (excess) electrons move onto/are located on the

(outer) surface

the (excess) electrons are equally spaced

(conditional on the first point being awarded)

(because) the electrons mutually repel

Condone “like charges repel” in the

context of electrons.

2 x AO

1

MARK SCHEME – A-LEVEL PHYSICS – 7408/2 – JUNE Want to earn $103 per month?

Question Answers Additional comments/Guidelines Mark AO

The triangle used to find the gradient covers more

than

50% of the horizontal scale.^1

Finding the gradient from their tangent 2

2.0 ± 0.3 × 106 3 (correct answer within limits only and

to better than 1 sf)

Unit N C–^1 or V m–^1 2 eg gradient at^ 0.30 m 0 − −1.2 × 106

0.6 (^) − 0

(Ignore minus sign and PoT errors

but numerical substitutions must be

accurate

Condone answer to more than

3 sf. Condone ‘kg m s-3^ A-1’ for

unit.

(Any alternative method that does not

use the relationship violates the rubric

e.g. V = kQ / r E = kQ / r^2 so E = V / r E = 060 × 106 0.

However, MP3 and MP4 can be awarded

4 2 x AO

2 x AO

MS 3.

1