MARK SCHEME for the October/November 2015 series 9702 PHYSICS. 9702/11 Paper 1 (Multiple Choice), maximum raw mark 40

Transcription

1 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/11 Paper 1 (Multiple Choice), maximum raw mark 40 Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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 Cambridge International AS/A Level October/November Question Number Key Question Number Key 1 B 21 B 2 B 22 A 3 A 23 B 4 A 24 C 5 B 25 A 6 C 26 A 7 C 27 D 8 B 28 A 9 D 29 B 10 D 30 A 11 A 31 C 12 D 32 A 13 C 33 B 14 A 34 C 15 B 35 A 16 D 36 A 17 B 37 D 18 D 38 D 19 D 39 D 20 B 40 B

3 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/12 Paper 1 (Multiple Choice), maximum raw mark 40 Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

4 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November Question Number Key Question Number Key 1 C 21 D 2 B 22 D 3 C 23 C 4 B 24 B 5 D 25 D 6 A 26 D 7 B 27 A 8 C 28 D 9 A 29 C 10 A 30 C 11 C 31 A 12 A 32 A 13 C 33 A 14 C 34 C 15 A 35 A 16 B 36 B 17 C 37 A 18 C 38 D 19 B 39 C 20 B 40 D

5 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/13 Paper 1 (Multiple Choice), maximum raw mark 40 Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

6 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November Question Number Key Question Number Key 1 A 21 C 2 D 22 C 3 A 23 C 4 B 24 D 5 B 25 B 6 B 26 B 7 A 27 B 8 B 28 C 9 C 29 B 10 C 30 A 11 C 31 A 12 D 32 A 13 D 33 D 14 A 34 A 15 B 35 A 16 D 36 A 17 B 37 D 18 C 38 C 19 A 39 C 20 B 40 D

7 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/21 Paper 2 (AS Structured Questions), maximum raw mark 60 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

8 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) temperature current [2] (allow amount of substance, luminous intensity) (b) (i) 1. E = (stress / strain =) [force / area] / [extension / original length] units of stress: kg m s 2 / m 2 and no units for strain units of E: kg m 1 s 2 A0 [1] 2. units for T: s, l: m and M: kg K 2 = T 2 E / M l 3 hence units: s 2 kg m 1 s 2 / kg 3 (= m 4 ) units of K: m 2 A1 [2] (ii) % uncertainty in E = 4% (for T 2 ) + 0.6% (for l 3 ) + 0.1% (for M) + 3% (for K 2 ) = 7.7% E = [( ) (0.892) 3 ] / (0.45) 2 = % of E = E = (1.6 ± 0.1) kg m 1 s 2 A1 [4] 2 (a) ps = (s) or T = (s) v = fλ or v = λ / T λ = = 0.06(0) m A1 [4] (b) 1500 = time-base setting or T = s time-base setting = 1.3 (1.25) µs cm 1 A1 [2] 3 (a) work done is force distance moved in direction of force or no work done along PQ as no displacement/distance moved in direction of force work done is same in vertical direction as same distance moved in direction of force [2]

9 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (b) (i) at maximum height t = 1.5 (s) or s = ½(u + v) t, s = 11 m and t = 1.5 s V v = V v = (11 2) / 1.5 = 15 (14.7) m s 1 A1 [2] (ii) straight line from (0,0) to (3.00, 25.5) [1] (iii) at maximum height V h = 25.5 / 3 (= 8.5 m s 1 ) ratio = mgh / ½ mv 2 = ( ) / (8.5) 2 = 3.0 (2.99) A1 [3] (iv) deceleration is greater/resultant force (weight and friction force) is greater time is less A1 [2] 4 (a) density = mass / volume mass = = 0.85 (0.853) kg [2] (b) pressure = force / area force = W cos 40 pressure = ( cos 40 ) / = 2.7 (2.66) 10 3 Pa A1 [3] (c) F = ma W sin 40 f = ma sin 40 f = f (= ) = 2.1 N [ if kg is used for the mass] A1 [3]

10 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) progressive: all particles have same amplitude stationary: no nodes or antinodes or maximum to minimum/zero amplitude progressive: adjacent particles are not in phase stationary: waves particles are in phase (between adjacent nodes) [2] (b) (i) wavelength 1.2 m (zero displacement at 0.0, 0.60 m, 1.2 m, 1.8 m, 2.4 m) either peaks at 0.30 m and 1.5 m and troughs at 0.90 m and 2.1 m or vice versa (but not both) maximum amplitude 5.0 mm [2] (ii) 180 or π rad A1 [1] (iii) at t = 0 particle has kinetic energy as particle is moving at t = 5.0 ms no kinetic energy as particle is stationary so decrease in kinetic energy (between t = 0 and t = 5.0 ms) [2] 6 (a) energy converted from chemical to electrical per unit charge [1] (b) (i) current = E / (R + r) = 6.0 / ( ) = 0.36 (0.364) A A1 [2] (ii) terminal p.d. = ( ) = 5.8 V or ( ) = 5.8 V A1 [1] (c) (i) use of R = ρl / A or proportionality with length and inverse proportionality with area or d 2 d / 2 and l / 2 gives resistance of Z = 2R Y = 24 (Ω) R = resistance of parallel combination = [1/24 + 1/12] 1 = 8(.0) (Ω) A1 [3] (ii) resistance of circuit less therefore current larger lost volts greater therefore terminal p.d. less [2] (d) power = I 2 R or VI or V 2 / R current in second circuit (= 6.0 / 12.5) = 0.48 (A) ratio = [(0.36) 2 16] / [(0.48) 2 12] = 0.75 [0.77 if full s.f. used] [3]

11 Page 5 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) (i) curved path towards negative ( ) plate (right-hand side) [1] (ii) range of α-particle is only few cm in air/loss of energy of the α-particles due to collision with air molecules/ionisation of the air molecules [1] (iii) V = E d = = 1.7 (1.68) MV A1 [2] (b) β have opposite charge to α therefore deflection in opposite direction β has a range of velocities/energies hence number of different deflections β have less mass or q / m is larger hence deflection is greater or β with (very) high speed (may) have less deflection [3] (c) emitted particle change in Z change in A α-particle 2 4 β-particle +1 0 A1 [1]

12 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/22 Paper 2 (AS Structured Questions), maximum raw mark 60 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

13 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) v = fλ λ = ( ) / ( ) ( = =) 0.65(2) pm A1 [3] (b) t = ( ) / ( ) ( = =) 0.28(3) Gs A1 [2] (c) mass, power and temperature all underlined and no others [1] (d) (i) arrow in the direction 30 to 40 south of east [1] (ii) triangle of velocities completed (i.e. correct scale diagram) or correct working given e.g. [ (14)(8.0) cos 60 ] 1/2 or [( cos 60 ) 2 + (8.0 sin 60 ) 2 ] 1/2 resultant velocity = 12(.2) (or 12.0 to 12.4 from scale diagram) m s 1 A1 [2] 2 (a) (i) v = u + at 0 = t t (= 3.6 / 3.0) = 1.2 s A1 [2] (ii) (distance to rest from P = ( ) / 2 =) 2.2 (2.16) m A1 [1] or [0 (3.6) 2 ] / [2 ( 3.0)] = 2.2 (2.16) m or ½ 3.0 (1.2) 2 = 2.2 (2.16) m or 0 + ½ 3.0 (1.2) 2 = 2.2 (2.16) m (b) distance = (= 3.84) v 2 = u 2 + 2as = (= 23.04) or x = 6.0 gives x = 1.68 (m) v 2 = (= 23.04) () () or correct method with intermediate time calculated (t = 1.6 s from Q to R) v = 4.8 m s 1 A0 [2]

14 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (c) straight line from v = 3.6 m s 1 to v = 0 at t = 1.2 s straight line continues with the same gradient as v changes sign straight line from v = 0 intercept to v = 4.8 m s 1 [3] (d) difference in KE = ½m(v 2 u 2 ) = ( ) [= ] = 2.3 (2.27) J A1 [2] 3 (a) (i) k = F / x or 1 / gradient (k = 4.4 / ( ) =) 81 (81.48) N m 1 A1 [2] (ii) work done = area under line or ½Fx or ½kx 2 (= =) 0.12 (0.119) J A1 [2] (b) (i) kinetic energy/e k of trolley/t (and block) changes to EPE/strain energy/elastic energy of spring EPE changes to KE of trolley/t and KE of block or to give lower KE to trolley [2] (ii) change in momentum = m(v + u) = 0.25 ( ) = 0.49 (0.488) N s A1 [2] 4 (a) product of the force and the perpendicular distance to/from a point/pivot [1] (b) (i) sin 30 or sin 30 or T 2.8 or or sin sin 30 = T 2.8 hence T = 2100 (2125) N A0 [2] (ii) (T v = 2100 cos 60 =) 1100 (1050) N A1 [1] (iii) there is an upward (vertical component of) force at A upward force at A + T v = sum of downward forces/weight+load/4500 N [2]

15 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) (i) I = V / R ( = 240 / 1500 =) 0.16 A A1 [2] (ii) I 2 = (= 0.24) 0.24 (350 + R) = 240 R = 650 Ω A1 [2] (iii) power = IV or I 2 R or V 2 /R ratio = ( ) / ( ) or [(0.24) 2 350] / [(0.16) 2 550] or (84 2 /350) / (88 2 / 550) or / = 1.4(3) A1 [2] (b) (i) p.d. across 350 Ω resistor = or p.d. across 550 Ω resistor = V 350 = 84 (V) and V 550 = 88 (V) gives V AB = 4.0 V or V 950 = 152 (V) and V R = 156 V gives V AB = 4.0 V A1 [2] (ii) p.d. across R increases or potential at B increases or V 350 decreases hence V AB increases [1] 6 (a) internal resistance causes lost volts p.d. across lamp is less than 12 V, power is less than 48 W [2] (b) (i) greater lost volts or p.d. across cell/lamp reduced, less current in lamp [1] (ii) p.d. across lamp/current in lamp decreases, hence resistance decreases [1] 7 (a) (i) 3.2 mm A1 [1] (ii) 20 mm A1 [1] (b) (i) energy is transferred/propagated (through the water) or wave profile/wavefronts move (outwards from dipper) so progressive [1] (ii) to produce waves with constant/zero phase difference/coherent waves [1]

16 Page 5 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (c) (i) path difference is λ water vibrates/oscillates with amplitude about mm [2] (ii) path difference is λ / 2 so little/no motion/displacement/amplitude [1] 8 (a) result: majority / most (of the α-particles) went straight through/were deviated by small angles conclusion: most of the atom is (empty) space or size/volume of nucleus very small compared with atom result: a small proportion were deflected through large angles or >90 or came straight back A1 conclusion: the mass or majority of mass is in a (very) small charged volume/region/nucleus A1 [4] (b) ρ = m / V mass of atom and mass of nucleus (approx.) equal stated or cancelled or values given e.g. 63 u or ratio = (r A ) 3 / (r N ) 3 = ( ) 3 / ( ) 3 or ratio = (d A ) 3 / (d N ) 3 = ( ) 3 / ( ) 3 = A1 [3]

17 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/23 Paper 2 (AS Structured Questions), maximum raw mark 60 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

18 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) energy or W: kg m 2 s 2 or power or P: kg m 2 s 3 intensity or I: kg m 2 s 2 m 2 s 1 (from use of energy expression) or kg m 2 s 3 m 2 (from use of power expression) indication of simplification to kg s 3 A1 [2] (b) (i) ρ: kg m 3, c: m s 1, f: s 1, x 0 : m substitution of terms in an appropriate equation and simplification to show K has no units A1 [2] (ii) I = (260) 2 ( ) 2 = (W m 2 ) = 31 (30.8) pw m 2 A1 [3] 2 (a) (i) (the loudspeakers) are connected to the same signal generator [1] (ii) 1. the waves (that overlap) have phase difference of zero or path difference of zero and so either constructive interference or displacement larger [1] 2. the waves (that overlap) have phase difference of (n + ½) 360 or (n + ½) 2π rad or path difference of (n + ½)λ and so either destructive interference or displacements cancel/smaller [1] 3. the waves (that overlap) are in phase or have phase difference of n360 or 2πn rad or path difference of nλ and so either constructive interference or displacement larger [1] (b) time period = s or 2 ms wave drawn is half time period amplitude 1.0 cm (same as Fig. 2.2) [3]

19 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) (i) 1. s = ut + ½ at = ½ 9.81 t 2 t = 6.3 (6.26) s A1 [2] 2. max E k (= mgh) = or calculation of v (= 61.4) and use of E K (= ½ mv 2 ) = ½ 0.27 (61.4) 2 () max E k = 510 (509) J A1 [2] (ii) velocity is proportional to time or velocity increases at a constant rate as acceleration is constant or resultant force is constant [1] (iii) use of v = at or v 2 = 2as or E = ½ mv 2 to give v = 61(.4) m s 1 [1] (b) (i) R increases with velocity resultant force is mg R or resultant force decreases acceleration decreases [3] (ii) at v = 40 m s 1, R = 0.6 (N) = 0.27 a a = 7.6 (7.58) m s 2 A1 [2] (iii) R = weight for terminal velocity either weight requires velocity to be about 80 m s 1 or at 60 m s 1, R is less than weight so does not reach terminal velocity [2] 4 (a) (i) reaction/vertical force = weight P cos 60 = cos 60 = 160 (163) N A1 [2] (ii) work done = 35 sin = 610 (606) J A1 [2]

20 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (b) (i) work done by force P = work done against frictional force [1] (ii) horizontal component of P is equal and opposite to frictional force vertical component of P + normal reaction force equal and opposite to weight [2] 5 (a) (i) resistance = V / I very high/infinite resistance at low voltages resistance decreases as V increases [3] (ii) p.d. from graph 0.50 (V) resistance = 0.5 / ( ) = 110 (114) Ω A1 [2] (b) (i) current (= 1.2 / 375) = A A1 [1] (ii) current in diode = (A) total resistance = 1.2 / = (Ω) resistance of R 1 = = 160 (159) Ω A1 or p.d. across diode = 0.5 V and p.d. across R 1 = 0.7 V () resistance of R 1 = 0.7 / = 160 (159) Ω (A1) [2] (iii) power = IV or I 2 R or V 2 / R ratio = ( ) / ( ) or [(4.4) 2 114] / [(3.2) 2 375] or [(0.5) 2 375] / [114 (1.2) 2 ] = 0.57 A1 [2] 6 (a) waves from loudspeaker (travel down tube and) are reflected at closed end two waves (travelling) in opposite directions with same frequency/wavelength overlap [2] (b) (i) 0.51 m A m A1 [2] (ii) A at open end, N at closed end, with an N and A in between, equally spaced (by eye) [1]

21 Page 5 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) stress or σ = F / A max. tension = UTS A = = 6800 (6750) N A1 [2] (b) ρ = m / V weight = mg = ρvg = ρalg 6750 = L 9.81 L = 5.9 (5.88) 10 3 m A1 or maximum mass = 6750 / 9.81 = 688 kg mass per unit length = ρa = kg m 1 L = 688 / = m () () (A1) or maximum mass = 6750 / 9.81 = 688 kg () volume = m / ρ = m 3 = LA () L = / = m (A1) [3] 8 (a) mass-energy proton number or charge nucleon number B2 [2] (b) (i) E k = ½ mv 2 and p = mv with working leading to [via E k = ½ m 2 v 2 / m or ½ m (p / m) 2 ] 2 p to E k = 2m (ii) p = (2E k m) ½ hence (2[E k m] α ) ½ = (2[E k m] Th ) ½ [1] 2 [E k ] Th 234 = [E k ] Th = J = 71(.5) kev A1 or calculation of speed of α-particle = m s 1 calculation of momentum of α-particle/nucleus = N s () [E k ] Th = J () = 71(.5) kev (A1) [3]

22 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/31 Paper 3 (Advanced Practical Skills 1), maximum raw mark 40 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

23 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) (iv) Value of d in range 19.5 cm to 20.5 cm with unit. [1] (c) (ii) Value of N with evidence of repeat readings. [1] (e) Six sets of readings of d and N scores 5 marks, five sets scores 4 marks etc. [5] Incorrect trend 1. Help from Supervisor 1. Range: [1] Smallest value of d < 9.5 cm. Column headings: [1] Each column heading must contain a quantity and a unit where appropriate. The presentation of quantity and unit must conform to accepted scientific convention e.g. d 1 / m 1. Consistency: [1] All values of d must be given to the nearest mm. Significant figures: [1] Every value of 1 / d must be given to the same number of significant figures as (or one more than) the number of significant figures in the corresponding value of d. Calculation: [1] N calculated correctly to the number of significant figures given by the candidate. (f) (i) Axes: [1] Sensible scales must be used. Awkward scales (e.g. 3:10) are not allowed. Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Scale markings should be no more than three large squares apart. Plotting: [1] All observations in the table must be plotted on the grid. Diameter of plotted points must be half a small square (no blobs ). Points must be plotted to an accuracy of half a small square. Quality: [1] All points in the table must be plotted (at least 5) for this mark to be awarded. Scatter of points must be no more than ±0.5 in the N direction from a straight line. (ii) Line of best fit: [1] Judge by balance of all points on the grid about the candidate s line (at least 5 points). There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled) by the candidate. Lines must not be kinked or thicker than half a square.

24 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (iii) Gradient: [1] The hypotenuse of the triangle must be greater than half the length of the drawn line. Do not allow x / y. Sign of gradient must match graph drawn. Both read-offs must be accurate to half a small square in both the x and y directions. y-intercept: [1] Either: Correct read-offs from a point on the line substituted into y = mx + c or an equivalent expression. Read-offs must be accurate to half a small square in both x and y directions. Or: Intercept read directly from the graph, with read-off accurate to half a small square. (g) Value of A = candidate s gradient and value of B = candidate s intercept. [1] Unit for A correct (e.g. m or cm or mm) and consistent with value. No unit given for B. [1] 2 (a) (ii) Value for x to the nearest mm. [1] x in the range m to m. [1] (b) (i) Correct calculation of C in m (correct to 2 s.f.). [1] (ii) Justification for significant figures in C linked to significant figures in x and h. [1] (c) (ii) Value for R with unit. [1] Evidence of repeat readings. [1] (iii) Absolute uncertainty in R in range 5 mm to 20 mm and correct method of calculation to obtain percentage uncertainty. If repeated readings have been taken, then the uncertainty can be half the range (but not zero) if the working is clearly shown. [1] (d) Second value of x. [1] Second value of R. [1] Second value of R < first value of R. [1] (e) (i) Two values of k calculated correctly. [1] (ii) Valid comment consistent with the calculated values of k, testing against a criterion specified by the candidate. [1]

25 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (f) (i) Limitations (4 max.) (ii) Improvements (4 max.) Do not credit A Not enough readings to draw a conclusion Take many readings for different holes and plot a graph/ obtain more k values and compare Few readings/ only one reading/ not enough readings for an accurate result/ repeat readings on its own/ take more readings and (calculate) average k B Ball rolls off block/ball does not move along straight line from the wood/rod does not hit marble square on each time/rod hits marble at an angle Small groove in the wood to place the marble C Difficult to measure distance rod is pulled back/difficult to hold rod still before release Use another stand or stop D Difficult to measure R with reason e.g. marble skids in sand leaving elongated hole/can t fit ruler in sand tray/parallax error Improved method for measuring R e.g. video with scale/use carbon paper/ink on marble/put scale on the sand E Difficult to flatten sand/know when sand is horizontal Use a straight edge/ use a spirit level F Difficult to measure x with reason e.g. wooden rod moves Method of measuring x/ clamp rule close by/ draw scale on rod

26 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/33 Paper 3 (Advanced Practical Skills 1), maximum raw mark 40 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

27 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (b) (i) Value for L to the nearest mm, with unit. [1] (c) Second value of h > first value of h. [1] (d) (ii) Six sets of readings of m, h and θ scores 5 marks, five sets scores 4 marks etc. [5] Help from Supervisor 1. Incorrect trend 1. Correct trend is h increases as m increases. Range: [1] Range of values to include m min < 60 g and m max > 80 g. Column headings: [1] Each column heading must contain a quantity and a unit. The presentation of quantity and unit must conform to accepted scientific convention e.g. h / cos θ (cm). Consistency: [1] All values of h must be given to the nearest mm. Significant figures: [1] Every value of h / cos θ must be given to 2 or 3 significant figures only. Calculation: [1] Values of h / cosθ calculated correctly to the number of significant figures given by the candidate. (e) (i) Axes: [1] Sensible scales must be used. Awkward scales (e.g. 3:10) are not allowed. Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Scale markings should be no more than three large squares apart. Plotting: [1] All observations in the table must be plotted on the grid. Diameter of plotted points must be half a small square (no blobs ). Points must be plotted to an accuracy of half a small square. Quality: [1] All points in the table must be plotted (at least 5) for this mark to be awarded. Scatter of points must be no more than 10 g in the m direction of a straight line. (ii) Line of best fit: [1] Judge by balance of all points on the grid about the candidate s line (at least 5 points). There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled) by the candidate. Lines must not be kinked or thicker than half a square.

28 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (iii) Gradient: [1] The hypotenuse of the triangle must be greater than half the length of the drawn line. Do not allow x / y. Sign of gradient must match graph drawn. Both read-offs must be accurate to half a small square in both the x and y directions. y-intercept: [1] Either: Correct read-offs from a point on the line substituted into y = mx + c or an equivalent expression. Read-offs must be accurate to half a small square in both x and y directions. Or: Intercept read directly from the graph, with read-off accurate to half a small square. (f) Value of A = candidate s gradient and value of B = candidate s intercept. [1] Unit for A correct (e.g. m kg 1 or cm g 1 ) and unit for B correct (m or cm or mm). [1] 2 (a) (iii) Values of x, y and z to the nearest mm with unit. [1] Value of z > value of x. [1] (iv) Absolute uncertainty in y of 1 mm to 4 mm and correct method of calculation to obtain percentage uncertainty. If repeated readings have been taken, then the uncertainty can be half the range (but not zero) if working is clearly shown. [1] (b) Correct calculation of C with consistent unit. [1] (c) (ii) Value for T with unit in range 5.0 s > T > 0.5 s. [1] Evidence of repeat readings for T. [1] (iv) Justification for significant figures in T 2 linked to significant figures in the (raw) times. [1] (d) Second values of x, y and z. Value of y within 5 mm of value in (a)(iii). [1] Second value of T. [1] Second value of T < first value of T. [1] (e) (i) Two values of k calculated correctly. [1] (ii) Valid comment consistent with the calculated values of k, testing against a criterion specified by the candidate. [1]

29 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (f) (i) Limitations (4 max.) (ii) Improvements (4 max.) Do not credit A Not enough readings to draw a conclusion Take many readings (for different masses) and plot a graph/ obtain more k values and compare Repeat readings on its own/ few readings/ only one reading/ not enough readings for an accurate result/ take more readings and (calculate) average k B Rod is bent when loaded Use smaller masses/ rigid/stiff/thick rod Just rod is bent / shorter rod C Difficult to get horizontal Use a spirit level or named instrument. D Difficult to measure distances with reason e.g. rod unstable/awkward with metre rule/rod moves/holding ruler mid-air Add a scale on rod/ use travelling microscope/ clamp ruler Parallax Do not award if reason given is bent rod. E y not constant with a reason e.g. spring/loop moves around during oscillations Cut groove or drill hole in wooden rod/ tape to wooden rod F Difficult to judge the start/end of an oscillation or Difficult to judge when to start/stop the stopwatch (Fiducial) marker at centre/ video and timer/view frame by frame/ motion sensor placed below/above More oscillations/ high speed camera/ reaction time/ human error G Oscillation in more than one plane/irregular oscillations Wind/draughts/ switch off air conditioning/ close doors and windows

30 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/34 Paper 3 (Advanced Practical Skills 2), maximum raw mark 40 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

31 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (b) (i) Value of θ to the nearest degree and in the range 135 to 165. [1] (ii) Value of L in range 5.0 to 10.0 cm, with unit. [1] (d) Six sets of readings of θ and L scores 5 marks, five sets scores 4 marks etc. [5] Incorrect trend 1. Help from Supervisor 1. Range: θ max 160 and θ min 140. Column headings: Each column heading must contain a quantity and a unit. The presentation of quantity and unit must conform to accepted scientific convention e.g. θ /. 1/sin(θ 90 ) must have no unit. Consistency: All values of L must be given to the nearest mm. Significant figures: Every value of 1/sin(θ 90 ) must be given to 2 or 3 significant figures only. Calculation: Values of 1/sin(θ 90 ) calculated correctly to the number of significant figures given by the candidate. [1] [1] [1] [1] [1] (e) (i) Axes: Sensible scales must be used. Awkward scales (e.g. 3:10) are not allowed. Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Scale markings should be no more than three large squares apart. Plotting: All observations in the table must be plotted on the grid. Diameter of plotted points must be half a small square (no blobs ). Points must be plotted to an accuracy of half a small square. [1] [1] Quality: [1] All points in the table must be plotted (at least 5) for this mark to be awarded. Scatter of points must be no more than ±0.3 (to scale) cm in the L direction from a straight line. (ii) Line of best fit: Judge by balance of all points on the grid about the candidate s line (at least 5 points). There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled) by the candidate. Lines must not be kinked or thicker than half a square. [1]

32 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (iii) Gradient: The hypotenuse of the triangle must be greater than half the length of the drawn line. Do not allow x / y. Sign of gradient must match graph drawn. Both read-offs must be accurate to half a small square in both the x and y directions. y-intercept: Either: Correct read-offs from a point on the line substituted into y = mx + c or an equivalent expression. Read-offs must be accurate to half a small square in both x and y directions. Or: Intercept read directly from the graph, with read-off accurate to half a small square. [1] [1] (f) Value of a = candidate s gradient and value of b = candidate s intercept. [1] Unit for a is correct (e.g. cm 1 ) and no unit for b. [1] 2 (a) (i) All values of d to nearest mm, with unit, in range 5 to 30 mm. [1] Value of l greater than value of d. [1] (ii) Correct calculation of V with consistent unit. [1] (b) Justification for significant figures in V linked to significant figures in d and l. [1] (c) (iii) t in range 5.00 s to s, with unit. [1] Evidence of repeat readings of t. [1] (d) Absolute uncertainty in t in range 0.5 s to 5.0 s and correct method of calculation to obtain percentage uncertainty. If repeated readings have been taken, then the absolute uncertainty can be half the range (but not zero) if working is clearly shown. [1] (e) Second values of d and l. Second value of t. [1] [1] Second value of t < first value of t. [1] (f) (i) Two values of k calculated correctly. [1] (ii) Valid comment consistent with the calculated values of k, testing against a criterion specified by the candidate. [1]

33 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (g) (i) Limitations (4 max.) (ii) Improvements (4 max.) Do not credit A Not enough readings to draw a conclusion Take more readings and plot a graph/ obtain more k values and compare Few readings/ only one reading/ not enough readings for an accurate result/ repeat readings on its own/ take more readings and (calculate) average k B d is small/large uncertainty in d Improved method of measuring d e.g. micrometer/vernier calipers/digital calipers/travelling microscope Difficult to measure d/ parallax error/ calipers on its own/ use bigger/larger components C Volume of component not accurate, with reason e.g. component not cylindrical/has groove. Method to find volume of component e.g. use liquid displacement method D Difficult to judge/know/see when LED goes out. Use dark(ened) room/ light meter/ light sensor/ cardboard tube over LED/ voltmeter to measure time for p.d. to fall below specific value Use video E Poor/dirty/loose contacts Method of cleaning contacts e.g. iron wool

34 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/35 Paper 3 (Advanced Practical Skills 1), maximum raw mark 40 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

35 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (b) (i) Value of a with consistent unit and in the range 0 to 50.0 cm. [1] (v) Value of V with unit to nearest V and in range 0 to 2 V. [1] (c) Six sets of readings of a, b and V scores 5 marks, five sets scores 4 marks etc. [5] Incorrect trend 1. Minor help from Supervisor 1. Major help from Supervisor 2. Range: a max a min 30.0 cm. Column headings: Each column heading must contain a quantity and a unit. The presentation of quantity and unit must conform to accepted scientific convention. e.g. a / m or a (m), 1/V / V 1. Consistency: All values of a and b must be given to the nearest mm. Significant figures: Every value of 1 / V must be given to the same number of significant figures as (or one more than) the number of significant figures in the corresponding value of V. Calculation: Values of 1 / V calculated correctly to the number of significant figures given by the candidate. [1] [1] [1] [1] [1] (d) (i) Axes: Sensible scales must be used. Awkward scales (e.g. 3:10) are not allowed. Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Scale markings should be no more than three large squares apart. Plotting: All observations in the table must be plotted on the grid. Diameter of plotted points must be half a small square (no blobs ). Points must be plotted to an accuracy of half a small square. [1] [1] Quality: [1] All points in the table must be plotted (at least 5) for this mark to be awarded. Scatter of points must be no more than ± m (5.0 cm) to scale in the b direction from a straight line. (ii) Line of best fit: Judge by balance of all points on the grid about the candidate s line (at least 5 points). There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled) by the candidate. Lines must not be kinked or thicker than half a square. [1]

36 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (iii) Gradient: The hypotenuse of the triangle must be greater than half the length of the drawn line. Do not allow x / y. Sign of gradient must match graph drawn. Both read-offs must be accurate to half a small square in both the x and y directions. y-intercept: Either: Correct read-off from a point on the line substituted into y = mx + c or an equivalent expression. Read-offs must be accurate to half a small square in both x and y directions. Or: Intercept read directly from the graph, with read-off accurate to half a small square. [1] [1] (e) Value of P = candidate s gradient and value of Q = candidate s intercept. [1] Unit for P is correct (e.g. m 1 V 1 ) and unit for Q is correct (e.g. V 1 ). [1] 2 (b) (iv) All values of x with unit to nearest mm. Average x 20.0 cm. [1] (c) (i) Value of θ to the nearest degree in the range 25 to 35. [1] (ii) Absolute uncertainty in θ in range 2 to 5 and correct method of calculation to obtain percentage uncertainty. If repeated readings have been taken, then the absolute uncertainty can be half the range (but not zero) if working is clearly shown. [1] (iii) Correct calculation of cos 2 (θ / 2). No unit. [1] (iv) Justification for significant figures in cos 2 (θ / 2) linked to significant figures in θ. [1] (d) (ii) T in range 0.5 s to 2.5 s, with unit. [1] Evidence of repeat readings of T. [1] (f) Second value of θ. Second values of T 1 and T 2. [1] [1] Second value of T 1 / T 2 < first value of T 1 / T 2 when rounded to 2 s.f. [1] (g) (i) Two values of k calculated correctly. [1] (ii) Valid comment consistent with the calculated values of k, testing against a criterion specified by the candidate. [1]

37 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (h) (i) Limitations (4 max.) (ii) Improvements (4 max.) Do not credit A Not enough readings to draw a conclusion Take more readings and plot a graph/ obtain more k values and compare Few readings/ only one reading/ not enough readings for an accurate result/ repeat readings on its own/ take more readings and (calculate) average k B Difficult to measure θ or read protractor with reason e.g. rod is above protractor/rod obscures view Improved method of measuring θ e.g. shadow projection with light above/thinner rod/rod with smaller diameter/plumb-lines hung from rod/larger protractor/360 protractor Just difficult to measure θ / smaller rod/ protractor reads to 1 C Oscillations or T affected by... e.g. air movement force on release different forces angle of release unwanted modes of oscillation Improved method of release e.g. card gate or switch off air conditioning/close windows/closed room Release by electromagnet/ cutting string/ damping/ air resistance/ friction D Large percentage uncertainty in time/period T is short Valid method to improve timing e.g. use video with timer/frame by frame/motion sensor and position at side of cradle or Increase T by... e.g. heavier nail/longer nail/string Oscillations too fast/ high/low speed camera/ video on its own/ human reaction time/ just difficult to determine time / fiducial marker E Valid problem linked to magnetism e.g. nail weakly magnetised/metal stand attracts nail/interference by Earth s magnetic field. Valid method to overcome problem linked with magnetism e.g. stroke nail more times/use of coil Nail loses magnetism F Method of fixing paper/protractor/magnets e.g. tape/blu-tack/draw protractor on paper Just stick paper without method

38 CAMBRIDGE INTERNATIONAL EXAMINATIONS Cambridge International Advanced Subsidiary and Advanced Level MARK SCHEME for the October/November 2015 series 9702 PHYSICS 9702/36 Paper 3 (Advanced Practical Skills 2), maximum raw mark 40 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 before 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 Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2015 series for 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.

39 Page 2 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (a) Value of H in the range 13.0 cm to 17.0 cm. [1] (c) (iii) Value of F to nearest 0.1 N. [1] (iv) Value of x correct and in range 3.5 cm to 4.5 cm. [1] (d) Six sets of readings of h w, h b and F scores 4 marks, five sets scores 3 marks etc. [4] Incorrect trend 1. Help from Supervisor 1. Range: [1] x max x min 6.0 cm. Column headings: [1] Each column heading must contain a quantity and a unit. The presentation of quantity and unit must conform to accepted scientific convention, e.g. (H x) 3 / cm 3. Consistency: [1] All values of h w and h b must be given to the nearest mm. Significant figures: [1] Significant figures for (H x) 3 must be the same as, or one greater than, the number of s.f. for (H x). Calculation: [1] Values of (H x) 3 calculated correctly. (e) (i) Axes: [1] Sensible scales must be used. Awkward scales (e.g. 3:10) are not allowed. Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Scale markings should be no more than three large squares apart. Plotting: [1] All observations in the table must be plotted on the grid. Diameter of plotted points must be half a small square (no blobs ). Points must be plotted to an accuracy of half a small square. Quality: [1] All points in the table must be plotted (at least 5) for this mark to be awarded. Scatter of points must be less than ± 0.2 N from a straight line in the F direction. (ii) Line of best fit: [1] Judged by balance of all points on the grid about the candidate s line (at least 5 points). There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled) by the candidate. Lines must not be kinked or thicker than half a square.

40 Page 3 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (iii) Gradient: [1] The hypotenuse of the triangle used must be greater than half the length of the drawn line. The method of calculation must be correct. Both read-offs must be accurate to half a small square in both the x and y directions. y-intercept: [1] Either: Correct read-offs from a point on the line substituted into y = mx + c or an equivalent expression. Read-offs must be accurate to half a small square in both x and y directions. Or: Intercept read directly from the graph, with read-off accurate to half a small square in the y direction. (f) Value of a = candidate s gradient and value of b = candidate s intercept. [1] Unit for a is correct (e.g. N cm 3 ) and unit for b is correct (e.g. N). [1] 2 (a) (i) All values of d to nearest cm and in range cm to cm. [1] (ii) All values of D to nearest 0.1 cm. [1] (b) Values of l, h and s present. Value of h to nearest 0.1 cm and in range 7.5 cm to 8.5 cm, with unit. [1] (c) (ii) t on answer line in range 1.00 s to s, with unit. [1] Evidence of repeated readings for t. [1] (iii) Absolute uncertainty in t in range 0.2 s to 0.5 s and correct method of calculation to obtain percentage uncertainty. If repeated readings have been taken, then the absolute uncertainty can be half the range (but not zero) if the working is clearly shown. [1] (iv) Calculation of g correct to the second s.f., with consistent unit (e.g. m s 2 ). [1] (d) (ii) Second values of d and t. [1] t greater for smaller d. [1] (e) (i) Two values of k calculated correctly. [1] (ii) Justification for significant figures in k linked to significant figures in t and d. [1] (iii) Valid comment consistent with the calculated values of k, tested against a criterion specified by the candidate. [1]

41 Page 4 Mark Scheme Syllabus Paper Cambridge International AS/A Level October/November (f) (i) Limitations (4 max.) (ii) Improvements (4 max.) Do not credit A Not enough readings to draw a conclusion Take more readings and plot a graph/ obtain more k values and compare Repeat readings on its own/ few readings/ only one reading/ take more readings and (calculate) average k/ two readings not enough for accurate results B Parallax error when measuring h or D Use calipers/ use set square as pointer Rule not vertical when measuring h C Plastic deforms when measuring larger d/diameter with tubing Use larger diameter axle instead of tubing D Push force to start flywheel may vary/push force may affect time Release mechanism, with detail/ use steeper ramp Force may be too large / start before top line E Flywheel doesn t travel straight/ flywheel hits (sides of) track Sensible method of preventing collision, e.g. level the track sideways/widen the track Reduce friction/ mark both sides of track F Use video with timer/ view frame by frame/ use light gates at start and end/ use longer track Reaction time