MARK SCHEME for the October/November 2014 series 5054 PHYSICS. 5054/22 Paper 2 (Theory), maximum raw mark 75

Size: px

Start display at page:

Download "MARK SCHEME for the October/November 2014 series 5054 PHYSICS. 5054/22 Paper 2 (Theory), maximum raw mark 75"

Kathlyn Hardy
5 years ago
Views:

1 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge Ordinary Level MARK SCHEME f the October/November 2014 series 5054 PHYSICS 5054/22 Paper 2 (They), maximum raw mark 75 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners meeting befe marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Rept f Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes f the October/November 2014 series f most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations.

2 Page 2 Mark Scheme Syllabus Paper Section A 1 (a) limit of proptionality (not breaking point) (b) (i) 8.5 cm cao (ii) cm (c) 4.0 (2.7 / 7.2) 5.0 (2.7 / 9.0) 1.5 (N) read from graph 11.2 (cm) kg g A1 [5] 2 (a) (i) Fd N m A1 (ii) fce not applied at right angles to the tap (b) long(er) distance needs small(er) fce (f same moment) inversely related/proptional [4] 3 (a) V 1 = p 2 V 2 / p 1 p α 1 / V (1.8 / 2.0) m cm 3 A1 (b) (i) (ρ = ) m / V (0.30 / 9.0) (.3333) kg / m (3333) g / cm 3 A1 (ii) helium mass / weight small (fraction of total / mass of air included) this includes the weight of the cylinder [6] 4 (a) (i) heat gained from burning fuel / combustion friction between moving parts / with air / road from (radiation of) Sun (ii) heat lost to air/surroundings by convection (currents) exhaust/hot gases/fumes from exhaust heat emitted (by hot car) by radiation (b) at start chemical energy decreases at start chemical energy to gravitational / potential energy (of car) increases at end of process kinetic energy (of car air) increases [5]

3 Page 3 Mark Scheme Syllabus Paper 5 (a) downward curve of crect curvature from marked 90 C hizontal line at marked 58 C downward (asymptotic) curve of crect curvature to marked 23 C (b) H marked halfway (by eye) along an intermediate hizontal line (c) (Q =) ml J A1 [6] 6 (a) (the molecules) move faster have me kinetic energy accelerate igne vibrate faster (b) (i) faster / energetic molecules escape average speed decreases slower molecules remain temperature depends on average KE heat taken from runner OR liquid becomes gas / vapour latent heat needed bonds broken heat taken from runner (ii) water vapour blown away surrounding air less humid [5] 7 (a) (i) lasts longer one cell can be replaced without switching off the circuit less (internal) resistance if one fails the others still wk (ii) 1.5 V (b) (i) (R = )V / I 1.5 / (Ω) 1.5 / ( ) 14 Ω A1 (ii) decreases resistance of wire increases [7] 8 (a) one label crect and not contradicted C, 1S and 1B all crect and clear and none contradicted A1 (b) any three from: magnetic field (between poles) (coil / wire) cuts field / flux field / flux cuts (coil / wire) field / flux changes (electromagnetic) induction brushes rub against / in contact with rings B3 (c) (half) distance across screen count divisions of / measure wavelength the wavelength cresponds to one rotation half distance multiplied by time base setting [7]

4 Page 4 Mark Scheme Syllabus Paper Section B 9 (a) changing speed / velocity change in speed / velocity / time constant (v u) / t constant constant / equal rate of change of speed / velocity A1 [2] (b) (a vect quantity has) direction [1] (c) (i) 1. X between t 0 and t < 10 s 2. Y between t > 20 s and t < 30 s 3. Z between t > 10 s and t < 20 s between t > 30 s and t < 40 s (ii) 1. two speed values from graph between 15 and 35 s (±1 mm) two cresponding time values from graph between 15 and 35 s (±1 mm) (a = ) v / t 500 m / s 2 A1 2. (F = ) ma N A1 (iii) 1. arrow labelled F perpendicular to surface of Earth arrow labelled R opposite to direction of travel (by eye) from rock 2. speed changes density / pressure of air changes cross-sectional area (of rock) changes (iv) it hits the ground / surface of the earth stops speed is zero [12] 10 (a) m / s [1] (b) (i) 1. decreases cao 2. no change cao 3. decreases cao (ii) 1. i crectly marked (to nmal) 2. r crectly marked (to nmal) [5] (c) (i) sin i / sin r = n sin i / sin r = 1.5 sin 89 / sin r = 1.5 sin 89 / ( ) A1 (ii) i equal to / close to 90 sin i / sin 45 sin 1 (1/n) / sin 1 (1 / 1.5) and r less than 45 = 1.5 and 41.8 i never bigger than sin i >1 r not be me than c 89 / 90 [5]

5 Page 5 Mark Scheme Syllabus Paper (d) (i) (sin) i = 0 ray enters directly / wavefront / light hits surface along nmal / perpendicular all together (sin) r = 0 no refraction all slows down together (ii) crect reflection at bottom surface (by eye) M1 second crect reflection at top and no refraction at either point A1 [4] 11 (a) same element same number of protons / atomic number different / particular number of neutrons nucleons [2] (b) (i) 38 cao (ii) 52 cao [2] 90 (c) 39( Y ) 90 ( Y ) 0 and (β) 0 1(β) ( ) 39 Y and 1 (β) [2] (d) (i) 87 / 29 3 (half-lives) / A1 (ii) any detect cresponding detection method detect film (solid-state) detect detection fogged GMtube ionisation chamber scintillation counter cloud chamber track seen no reduction with paper (use of) electric/magnetic field describe pattern of track M1 complete reduction with aluminium/lead crect deflection of track in electric/magnetic field no other track A1 (iii) 1. unpredictable not be known in advance no set time between emissions fluctuates not fixed counts obtained varies 2. any two from: direction / in space time which nucleus decays B2 [9]

MARK SCHEME for the October/November 2015 series 9702 PHYSICS

MARK SCHEME for the October/November 2015 series 9702 PHYSICS CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME f the October/November 2015 series 9702 PHYSICS 9702/23 Paper 2 (AS Structured Questions),