AQA Qualifications AQA Certificates PHYSICS. Paper 1 Mark Scheme. 8403/1 January Version/Stage: 1.0 (Final Mark Scheme)

Transcription

1 AQA Qualifications AQA Certificates PHYSICS Paper Mark Scheme 8403/ January 204 Version/Stage:.0 (Final Mark Scheme)

2 Mark schemes are prepared by the Lead Assessment Writer and considered, together with the relevant questions, by a panel of subject teachers. This mark scheme includes any amendments made at the standardisation events which all associates participate in and is the scheme which was used by them in this examination. The standardisation process ensures that the mark scheme covers the students responses to questions and that every associate understands and applies it in the same correct way. As preparation for standardisation each associate analyses a number of students scripts: alternative answers not already covered by the mark scheme are discussed and legislated for. If, after the standardisation process, associates encounter unusual answers which have not been raised they are required to refer these to the Lead Assessment Writer. It must be stressed that a mark scheme is a working document, in many cases further developed and expanded on the basis of students reactions to a particular paper. Assumptions about future mark schemes on the basis of one year s document should be avoided; whilst the guiding principles of assessment remain constant, details will change, depending on the content of a particular examination paper. Further copies of this Mark Scheme are available from aqa.org.uk Copyright 204 AQA and its licensors. All rights reserved. AQA retains the copyright on all its publications. However, registered schools/colleges for AQA are permitted to copy material from this booklet for their own internal use, with the following important exception: AQA cannot give permission to schools/colleges to photocopy any material that is acknowledged to a third party even for internal use within the centre.

3 MARK SCHEME AQA Certificates Physics 8403/ January 204 MARK SCHEME Information to Examiners. 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. 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 lines 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. Marking of lists This applies to questions requiring a set number of responses, but for which students have provided extra responses. The general principle to be followed in such a situation is that right + wrong = wrong. Each error/contradiction negates each correct response. So, if the number of error/contradictions equals or exceeds the number of marks available for the question, no marks can be awarded. However, responses considered to be neutral (indicated as * in example ) are not penalised. 3 of 9

4 MARK SCHEME AQA Certificates Physics 8403/ January 204 Example : What is the ph of an acidic solution? ( mark) Student Response Marks awarded 4,8 0 2 green, red*, 5 4 red*, 8 0 Example 2: Name two planets in the solar system. (2 marks) Student Response Marks awarded Neptune, Mars, Moon 2 Neptune, Sun, Mars, Moon Use of chemical symbols / formulae If a student writes a chemical symbol / formula instead of a required chemical name, full credit can be given if the symbol / formula is correct and if, in the context of the question, such action is appropriate. 3.3 Marking procedure for calculations Full marks can be given for a correct numerical answer, as shown in the column answers, without any working shown. However if the answer is incorrect, mark(s) can be gained by correct substitution / working and this is shown in the extra information column; 3.4 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. 3.5 Errors carried forward Any error in the answers to a structured question should be penalised once only. Papers should be constructed in such a way that the number of times errors can be carried forward are kept to a minimum. Allowances for errors carried forward are most likely to be restricted to calculation questions and should be shown by the abbreviation e.c.f. in the marking scheme. 3.6 Phonetic spelling The phonetic spelling of correct scientific terminology should be credited unless there is a possible confusion with another technical term. 3.7 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. 4 of 9

5 MARK SCHEME AQA Certificates Physics 8403/ January 204 Quality of Written Communication and levels marking In Question 3(d) students are required to produce extended written material in English, and will be assessed on the quality of their written communication as well as the standard of the scientific response. Students will be required to: use good English organise information clearly use specialist vocabulary where appropriate. The following general criteria should be used to assign marks to a level: Level : Basic Knowledge of basic information Simple understanding The answer is poorly organised, with almost no specialist terms and their use demonstrating a general lack of understanding of their meaning, little or no detail The spelling, punctuation and grammar are very weak. Level 2: Clear Knowledge of accurate information Clear understanding The answer has some structure and organisation, use of specialist terms has been attempted but not always accurately, some detail is given There is reasonable accuracy in spelling, punctuation and grammar, although there may still be some errors. Level 3: Detailed Knowledge of accurate information appropriately contextualised Detailed understanding, supported by relevant evidence and examples Answer is coherent and in an organised, logical sequence, containing a wide range of appropriate or relevant specialist terms used accurately. The answer shows almost faultless spelling, punctuation and grammar. 5 of 9

6 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question (a) the forces are equal in size and act in opposite directions AO.2a (b)(i) forwards / to the right / in the direction of the 300 N force answers in either order AO2.2c accelerating (b)(ii) constant velocity to the right AO2.2e (b)(iii) resultant force is zero accept forces are equal / balanced AO/AO2.2b so boat continues in the same direction at the same speed Question continues on the next page 6 of 9

7 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question continued (b)(iv) parallelogram or triangle is correctly drawn with resultant 3 AO2.2b value of resultant in the range 545 N 595 N parallelogram drawn without resultant gains mark If no triangle or parallelogram drawn: drawn resultant line is between the two 300 N forces gains mark drawn resultant line is between and longer than the two 300 N forces gains 2 marks Total 0 7 of 9

8 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 2 2(a) refraction AO 2.5a 2(b) towards the normal AO 2.5a 2(c)(i) convex AO 2.6b 2(c)(ii) principal focus accept focal point AO 2.6b 2(d) parallel on left refracted towards the normal at first surface AO2 2.6a refraction away from normal at second surface passes through or heads towards principal focus 2(e) refractive index accept material from which it is made AO 2.6d (radius of) curvature (of the sides) accept shape / radius do not accept power of lens ignore thickness / length Question 2 continues on the next page 8 of 9

9 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 2 continued 2(f) 5 (dioptre) /0.2 gains mark 0.05 gains mark 2 AO2 2.6k Total 2 9 of 9

10 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 3 3(a) neutrons and protons AO 6.a 3(b) 0 (+) AO 6.b 3(c)(i) total positive charge = total negative charge accept protons and electrons have an equal opposite charge AO 6.c (because) no of protons = no of electrons 3(c)(ii) ion positive AO/AO2 6.d Question 3 continues on the next page 0 of 9

11 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 3 continued Spec. Ref. 3(d) 6 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 refer to the information on page 5 and apply a best-fit approach to the marking. 0 marks Level ( 2 marks) Level 2 (3 4 marks) Level 3 (5 6 marks) No relevant content There is a basic description of at least one of the particles in terms of its characteristics. There is a clear description of the characteristics of both particles or a full description of either alpha or beta particles in terms of their characteristics. There is a clear and detailed description of both alpha and beta particles in terms of their characteristics. examples of the physics points made in the response: structure alpha particle consists of a helium nucleus alpha particle consists of 2 protons and 2 neutrons a beta particle is an electron a beta particle comes from the nucleus AO 6.2c,e penetration alpha particles are very poorly penetrating alpha particles can penetrate a few cm in air alpha particles are absorbed by skin alpha particles are absorbed by thin paper beta particles can penetrate several metres of air beta particles can pass through thin metal plate / foil Question 3 continues on the next page of 9

12 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 3 continued beta particles can travel further than alpha particles in air beta particles can travel further than alpha particles in materials eg metals deflection alpha particles and beta particles are deflected in opposite directions in an electric field beta particles are deflected more than alpha particles alpha particles have a greater charge than beta particles but beta particles have much less mass or beta particles have a greater specific charge than alpha particles Total 3 2 of 9

13 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 4 4(a)(i) 50 AO2 3.4e 4(a)(ii) transferred to the surroundings by heating reference to sound negates mark AO 3.4c 4(a)(iii) /600 gains mark accept 75% for 2 marks maximum of mark awarded if a unit is given 2 AO2 3.4d 4(a)(iv) 20 (s) correct answer with or without working gains 2 marks 2 AO2 4.3b correct substitution of 600/30 gains mark 4(b)(i) to avoid bias AO3 4.3q 4(b)(ii) use less power and last longer LED costs 6, 40 filament bulbs cost 80 or filament costs (5 times) more in energy consumption AO3 4.p Question 4 continues on the next page 3 of 9

14 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 4 continued 4(b)(iii) any one from: availability of bulbs colour output temperature of bulb surface AO3 4.3q Total 0 4 of 9

15 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 5 5(a) solid particles vibrate about fixed positions AO 3.a closely packed gas particles move randomly far apart accept regular accept particles move faster accept freely for randomly 5(b) amount of energy required to change the state of a substance from liquid to gas (vapour) AO 3.e unit mass / kg dependent on first marking point 5(c) 4000 or (J) accept 4400 or AO2 3.f correct substitution of gains mark 5(d) AB changing state from solid to liquid / melting AO/AO2 3. at steady temperature BC temperature of liquid rises until it reaches boiling point dependent on first AB mark dependent on first BC mark Total 2 5 of 9

16 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 6 6(a)(i) generator AO 5.2b 6(a)(ii) alternating current AO 4.2b 6(a)(iii) voltmeter / CRO / oscilloscope / cathode ray oscilloscope AO 4.e 6(b)(i) time AO 5.2f 6(b)(ii) peaks and troughs in opposite directions AO2 5.2e amplitude remains constant dependent on first marking point 6(b)(iii) wave modified to omit all values above or below x-axis AO2 4.2d same amplitude and wavelength as original dependent on first marking point 6(b)(iv) diode AO 4.2d 6(c) any two from: increase speed of coil strengthen magnetic field increase area of coil do not accept larger 2 AO 5.2f Total 6 of 9

17 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 7 7(a)(i) frequency wavelength AO 2.2a 7(a)(ii) 0 5 to 0 4 AO 2.2a 7(b) correct substitution of / 500 gains mark 2 AO/AO2 2.h Hz 7(c)(i) (skin) burns AO 2.2d 7(c)(ii) skin cancer / blindness AO 2.2d 7(d)(i) any one from: (detecting) bone fractures (detecting) dental problems treating cancer AO 2.2g 7(d)(ii) any one from: affect photographic film absorbed by bone transmitted by soft tissue kill (cancer) cells answer must link to answer given in (d)(i) AO 2.2f Question 7 continues on the next page 7 of 9

18 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 7 continued 7(d)(iii) 9/36 = /2 = /6 = 0.25 accept: 36/9 = 4 2/0.5 = 4 6/4 = 4 2 AO3 2.2h conclusion based on calculation two calculations correct with a valid conclusion scores 2 marks one correct calculation of k scores mark Total 3 8 of 9

19 MARK SCHEME AQA Certificates Physics 8403/ January 204 Question 8 8(a) terminal AO.5b 8(b) 5.4 (kg) correct substitution of 54 = m 0 gains mark 2 AO2.5c 8(c)(i) 0 a 0 some upward force accept some drag / air resistance AO/AO2.5b reduced resultant force 8(c)(ii) 0 upward force = weight (gravity) resultant force zero AO/AO2.5a,b Total 9 9 of 9