Cambridge A Level Physics 9702 — 2003 May/June Paper 2 · Variant 1

Centre Number Candidate Number | Name CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Advanced Subsidiary Level and Advanced Level PHYSICS Paper 2 Candidates answer on the Question Paper. No Additional Materials are required. 9702/02 May/June 2003 1 hour READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen in the spaces provided on the Question Paper. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. You may lose marks if you do not show your working or if you do not use appropriate units. If you have been given a label, look at the details. If any details are incorrect or missing, please fill in your correct details in the space given at the top of this page. Stick your personal label here, if provided. For Examiner’s Use 1 2 3 4 5 6 Total This document consists of 14 printed pages and 2 blank pages. SJF2604/CG S46439/4a @UCLES 2003 UNtersiry of CAMBRIDGE Local Examinations Syndicate [Turn over

Data speed of light in free space, permeability of free space, permittivity of free space, elementary charge, the Planck constant, unified atomic mass constant, rest mass of electron, rest mass of proton, molar gas constant, the Avogadro constant, the Boltzmann constant, gravitational constant, acceleration of free fall, c= 3.00 x 108 ms My = 4010-7 Hm €y = 8.85 x 10712 Fm e= 1.60 x 10-19C h=6.63 x 1074 Js u= 1.66 x 10-27 kg m, = 9.11 x 10-3! kg m, = 1.67 x 10-27 kg R= 8.31 JK mol"! Ng = 6.02 x 1075 mol-" k = 1.38 x 10-3 JK“! G = 6.67 x 10711 Nm? kg~? g= 9.81 ms~? 9702/2/MIJ03

Formulae uniformly accelerated motion, work done on/by a gas, gravitational potential, simple harmonic motion, velocity of particle in s.h.m., resistors in series, resistors in parallel, electric potential, capacitors in series, capacitors in parallel, energy of charged capacitor, alternating current/voltage, hydrostatic pressure, pressure of an ideal gas, radioactive decay, decay constant, critical density of matter in the Universe, equation of continuity, Bernoulli equation (simplified), Stokes’ law, Reynolds’ number, drag force in turbulent flow, Py+ s=ut+gat2 v2 = u2+2as W= pAv = &m p r a=-—@?x v= vy, cos ot v= 0V(x3 — x?) R=R,+Ry+... VR = 1/R, + 1/Ry +... __@Q © 4tégr WC = 1/0, + 1/0, +... C=C, +O,+... w= tav X=xX,sin ot X= Xy exp(- At) A= 0.693 4 3H2 Po= BnG Av = constant 2PVS = Po + $pvB F=Arnv vr R= f F= Brpv? 9702/2/NJ03 [Turn over

4 Answer all the questions in the spaces provided. 1. Complete Fig. 1.1 to show each quantity and its unit. quantity unit speed density 2 (a) (i) Define displacement. (ii) Use your definition to explain how it is possible for a car to travel a certain distance and yet have zero displacement. (b) Acar starts from rest and travels upwards along a straight road inclined at an angle of 5,0° to the horizontal, as illustrated in Fig. 2.1. mal 450m car, ‘ mass 800kg 5 Fig. 2.1 [4] 9702/2IMVJO3 For Examiner's

5 For Examiner's The length of the road is 450m and the car has mass 800kg. The speed of the car increases at a constant rate and is 28 ms" at the top of the slope. (i) Determine, for this car travelling up the slope, 1. its acceleration, aACCeleration = …cceesscesccseeseceeeeeteneees ms= [2] 2. the time taken to travel the length of the slope, time taken = oo... eeeceecseeeeeeeeseenenereeeeenens s [2] 3. the gain in kinetic energy, gain in kinetic energy = …c ce ceeceeseeeseceeeaeeee eens J [2] ‘9702/2/M/J03 [Turn over

6 4. the gain in gravitational potential energy. gain in potential energy = «J [3] (ii) Use your answers in (i) to determine the useful output power of the car. (iii) Suggest one reason why the actual power output of the car engine is greater than that calculated in (ii). 9702/2/MiJ03 For Examiner's } | ; |

3 7 (a) Fig. 3.1 shows the variation with tensile force of the extension of a copper wire. extension A 0 force Fig. 3.1 (i) State whether copper is a ductile, brittle or polymeric material. (ii) 1. On Fig. 3.1, mark with the letter L the point on the line beyond which Hooke’s law does not apply. 2. State how the spring constant for the wire may be obtained from Fig. 3.1. For Examiner's Use 9702/2/M/J03 {Turn over

8 For (b) A copper wire is fixed at one end and passes over a pulley. A mass hangs from the free end of the wire, as shown in Fig. 3.2. . 2.5m —- ' 1 1 1 = ' ' ‘ H pointer copper wire mass Fig. 3.2 The length of wire between the fixed end and the pulley is 2.5m. When the mass on the wire is increased by 6.0kg, a pointer attached to the pulley rotates through an angle of 6.5°. The pulley, of diameter 3.0 cm, is rough so that the wire does not slide over it. (i) For this increase in mass, 1. show that the wire extends by 0.17cm, 2. calculate the increase in strain of the wire. increase in Strain = … eee seeeseeeeeeesseeseeeeee (4) 9702/2/M/JO3

For 8 Examiner's (ii) The area of cross-section of the wire is 7.9x10-’m?. Calculate the increase in stress produced by the increase in load. increase iN StreSS =o... cceeeeeeeeeseretteeeee Pa [3] (iii) Use your answers to (i) 2 and (ii) to determine the Young modulus of copper. YOUNG MOMUIUS = …cseeeeeeeeseeereeeeneeeee Pa [2] (iv) Suggest how you could check that the elastic limit of the wire is not exceeded when the extra load is added. 9702/2/M/J03 [Turn over

4 10 (a) State three conditions that must be satisfied in order that two waves may interfere. (b) The apparatus illustrated in Fig.4.1 is used to demonstrate two-source interference using light. i = 1 1 ' ee ee eee light, > ha wavelength A < | a double slit screen Fig. 4.1 (not to scale) The separation of the two slits in the double slit arrangement is a and the interference fringes are viewed on a screen at a distance D from the double slit. When light of wavelength A is incident on the double slit, the separation of the bright fringes on the screen is x. (i) 1. Suggest a suitable value for the separation a of the slits in the double slit. 2. Write down an expression relating A, a, D and x. 2] 9702/2/M/J03 For Examiner's Use

1 (ii) Describe the effect, if any, on the separation and on the maximum brightness of the fringes when the following changes are made. 1. The distance Dis increased to 2D, keeping a and A constant. SOPALALION: …csesecseseresssesesssecscssseseescoeseseseesesensassssnssesacaeacsereeseneassceesseneasarsensetses MAXIMUM brIGhtNeSS: …sccscsecsseeseesssneseeeesecatsneassetasensscseseesseeeaseneseenseneseaeenene The wavelength / is increased to 1.54, keeping a and D constant. separation MAXIMUM DrightMeSS: …ssesersereeeeseserseseeseseensssstseassesesssstseseacecssenstsateseseneentees The intensity of the light incident on the double slit is increased, keeping A, a and D constant. separation: MAXIMUM DriGhtNESS: …ssssseseeecseeeseseseessseenscssensesenssesseerseeeeeensersnesenesesasecseeees [7] Examiner's Use 9702/2/M/JO3 {Turn over

12 5 A filament lamp operates normally at a potential difference (p.d.) of 6.0 V. The variation with p.d. V of the current Iin the lamp is shown in Fig. 5.1. 60 IimA 50 30 F 20 10 VIV Fig.5.1 (a) Use Fig. 5.1 to determine, for this lamp, (i) the resistance when it is operating at a p.d. of 6.0V, resistance 9702/2/MVJO3 For

13 (ii) the change in resistance when the p.d. increases from 6.0 V to 8.0 V. change in resistance = … ee secesececeeeseesssenseeees Q [4] (b) The lamp is connected into the circuit of Fig. 5.2. R Sa SS) 2002 Fig. 5.2 Ris a fixed resistor of resistance 200 Q. The battery has e.m.f. E and negligible internal resistance. (i) On Fig. 5.1, draw a line to show the variation with p.d. V of the current J in the resistor R. (ii) Determine the e.m.f. of the battery for the lamp to operate normally. 9702/2/M/JO3 [Turn over Examiner's Use

14 6 (a) A student is provided with a freshly prepared sample of a radioactive material and the count rate C from the source is found to vary with time tas shown in Fig. 6.1(a). ca cA Cy C C24 cya C44 C/4 0 T 1 1 0 T 1 7 0 50 100 150 5 0 50 100 150 is Fig. 6.1(a) Fig. 6.1(b) (b) A second similar sample of the radioactive material is then prepared and the student repeats the experiment, but with the sample at a higher temperature. The variation with time of the count rate for the second sample is shown in Fig. 6.1(b). State the evidence that is provided by these two experiments for (i) the random nature of radioactive decay, The radioactive source in (a) is an isotope of radon (729Rn) that emits o-radiation to become polonium (Po). (i) State the number of neutrons in one nucleus of radon-220. (ii) Write down a nuclear equation to represent the radioactive decay of a nucleus of radon. [3] 9702/2/M/JO3 Examiner's