Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level. Published

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1 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level PHYSICS 9702/21 Paper 2 AS Level Structured Questions October/November 2016 MARK SCHEME Maximum Mark: 60 Published 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 2016 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. This document consists of 5 printed pages. [Turn over

2 Page 2 Mark Scheme Syllabus Paper 1 (a) (density =) mass / volume [1] (b) (i) d = [(6 7.5) / (π 8100)] 1/3 = 0.12(1) m A1 [1] (ii) percentage uncertainty = (4 + 5) / 3 (= 3%) fractional uncertainty = ( ) / 3 (= 0.03) absolute uncertainty (= ) = d = ± m A1 [3] 2 (a) fce per unit positive charge [1] (b) (i) time = / = s ( s) A1 [1] (ii) E = V / d = 2500 / = N C 1 ( N C 1 ) A1 [2] (iii) a = Eq / m F = ma and F = Eq = ( ) / = m s 2 A1 [2] 2 (iv) s = ut + ½at = ½ ( ) 2 = (m) distance from plate = = 0.6 cm (allow 1 me s.f.) A1 [3] (v) electric fce gravitational fce (on electron)/weight acceleration due to electric field acceleration due to gravitational field [1] (vi) v X t graph: hizontal line at a non-zero value of v X v Y t graph: straight line through the igin with positive gradient [2]

3 Page 3 Mark Scheme Syllabus Paper 3 (a) fce/load is proptional to extension/compression (provided proptionality limit is not exceeded) [1] (b) (i) k = F / x k = gradient k = 600 N m 1 A1 [2] (ii) (W =) ½kx 2 (W =) ½Fx (W =) area under graph (W =) (0.040) 2 = 0.48 J (W =) = 0.48 J A1 [2] (iii) 1. (E K =) ½mv 2 = ½ = 0.45 J A1 [2] 2. (wk done against resistive fce =) [= 0.03(0) J] average resistive fce = / = 0.75 N A1 [3] (iv) efficiency = [useful energy out / total energy in] ( 100) = [0.45 / 0.48] ( 100) = % A1 [2] 4 (a) the number of oscillations per unit time M1 of the source/of a point on the wave/of a particle (in the medium) A1 [2] the number of wavelengths/wavefronts per unit time (M1) passing a (fixed) point (A1) (b) T period = (µs) (= 625 µs) M1 frequency = 1 / ( ) 1 / ( ) = 1600 Hz A1 [2] (c) (i) f maximum frequency: f o = f s v / (v v s ) 1640 = ( ) / (330 v s ) v s = 8(.0) m s 1 (8.049 m s 1 ) A1 [2] (ii) loudspeaker moving towards observer causes rise in/higher frequency loudspeaker moving away from observer causes fall in/lower frequency [2] repeated rise and fall/higher and then lower frequency (M1) caused by loudspeaker moving towards and away from observer (A1)

4 Page 4 Mark Scheme Syllabus Paper 5 (a) wave incident on/passes by through an aperture/edge wave spreads (into geometrical shadow) [2] (b) nλ = d sinθ substitution of θ = 90 sinθ = = d sin 90 line spacing = m A1 [3] (c) wavelength of red light is longer (than 500 nm) M1 (each der/fourth der is now at a greater angle so) the fifth-der maximum cannot be fmed/not fmed A1 [2] 6 (a) wk done energy (transfmed) (from electrical to other fms) charge [1] (b) (i) 1. V = IR E = IR I = 14 / 6.0 = 2.3 (2.33) A A1 [2] 2. total resistance of parallel resists = 8.0 Ω current = 14 / ( ) = 1.0 A A1 [2] (ii) P = EI (allow P = VI) P = V 2 / R P = I 2 R change in power = ( ) (14 1.0) (14 2 / 6.0) (14 2 / 14) ( ) ( ) = 19 W (18 W if 2.3 A used) A1 [2] (c) I = Anvq ratio = (0.50n / n) (1.8 A / A) ratio = = 0.90 A1 [2]

5 Page 5 Mark Scheme Syllabus Paper 7 (a) hadron not a fundamental particle/lepton is fundamental particle hadron made of quarks/lepton not made of quarks strong fce/interaction acts on hadrons/does not act on leptons [1] (b) (i) proton: up, up, down / uud neutron: up, down, down / udd [2] (ii) composition: 2(uud) + 2(udd) = 6 up, 6 down / 6u, 6d [1] (c) (i) most of the atom is empty space the nucleus (volume) is (very) small compared to the atom [1] (ii) nucleus is (positively) charged the mass is concentrated in (very small) nucleus/small region/small volume/small ce the majity of mass in (very small) nucleus/small region/small volume/small ce [2]

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),