Page 16 5. (a) A student is using an elastic band to model the expansion of the Universe. knot clamp elastic band V W X Y One end of the band is fixed in a clamp stand at V. Knots are tied in the band to represent galaxies. The knots are at regular intervals of 0·10 m, at points W, X and Y as shown. 0·00 0·05 0·10 0·15 0·20 0·25 0·30 0·35 0·40 V W X Y distance (m) The other end of the elastic band is pulled slowly for 2·5 seconds, so that the band stretches. The knots are now in the positions shown below. 0·00 0·05 0·10 0·15 0·20 0·25 0·30 0·35 0·40 V W X Y distance (m) Page 17 MARKS DO NOT WRITE IN THIS MARGIN 5. (a) (continued) (i) Complete the table to show the average speeds of the knots X and Y. Knot Average speed (m s−1) W 0·008 X Y Space for working (ii) Explain why this model is a good simulation of the expansion of the Universe. [Turn over 2 1 Page 18 MARKS DO NOT WRITE IN THIS MARGIN 5. (continued) (b) When viewed from the Earth, the continuous emission spectrum from the Sun has a number of dark lines. One of these lines is at a wavelength of 656 nm. 656 nm In the spectrum of light from a distant galaxy, the corresponding dark line is observed at 667 nm. Calculate the redshift of the light from the distant galaxy. Space for working and answer 3 Page 19 MARKS DO NOT WRITE IN THIS MARGIN 6. A website states “Atoms are like tiny solar systems with electrons orbiting a nucleus like the planets orbit the Sun”. Use your knowledge of physics to comment on this statement. [Turn over 3 Page 20 MARKS DO NOT WRITE IN THIS MARGIN 7. An experiment is set up to investigate the behaviour of electrons in electric fields. electron beam anode cathode parallel metal plates S 250 V 2·0 kV – – + + (a) Electrons are accelerated from rest between the cathode and the anode by a potential difference of 2·0 kV. Calculate the kinetic energy gained by each electron as it reaches the anode. Space for working and answer (b) The electrons then pass between the two parallel metal plates. The electron beam current is 8·0 mA. Determine the number of electrons passing between the metal plates in one minute. Space for working and answer 3 4 Page 21 MARKS DO NOT WRITE IN THIS MARGIN 7. (continued) (c) The switch S is now closed. The potential difference between the metal plates is 250 V. The path of the electron beam between the metal plates is shown. path of electron beam 0 V + 250 V Complete the diagram to show the electric field pattern between the two metal plates. (An additional diagram, if required, can be found on Page 38.) [Turn over 1 Page 22 MARKS DO NOT WRITE IN THIS MARGIN 8. The diagram shows part of an experimental fusion reactor. plasma magnets The following statement represents a reaction that takes place inside the reactor. + → + 2 3 4 1 1 1 2 0 H H He n The masses of the particles involved in the reaction are shown in the table. Particle Mass (kg) 2 1 H 3·3436 × 10−27 3 1 H 5·0083 × 10−27 4 2 He 6·6465 × 10−27 1 0 n 1·6749 × 10−27 (a) Explain why energy is released in this reaction. (b) Calculate the energy released in this reaction. Space for working and answer 1 4 Page 23 MARKS DO NOT WRITE IN THIS MARGIN 8. (continued) (c) Magnetic fields are used to contain the plasma inside the fusion reactor. Explain why it is necessary to use a magnetic field to contain the plasma. (d) The plasma consists of charged particles. A positively charged particle enters a region of the magnetic field as shown. positively charged particle region of magnetic field into page Determine the direction of the force exerted by the magnetic field on the positively charged particle as it enters the field. [Turn over 1 1 Page 24 MARKS DO NOT WRITE IN THIS MARGIN 9. A student carries out an experiment to measure the wavelength of microwave radiation. Microwaves pass through two gaps between metal plates as shown. microwave source metal plates detector 282 mm 204 mm meter second order maximum central maximum B A As the detector is moved from A to B, a series of maxima and minima are detected. (a) The microwaves passing through the gaps are coherent. State what is meant by the term coherent. (b) Explain, in terms of waves, how a maximum is produced. (c) The measurements of the distance from each gap to the second order maximum are shown in the diagram above. Calculate the wavelength of the microwaves. Space for working and answer 1 1 3 Page 25 MARKS DO NOT WRITE IN THIS MARGIN 9. (continued) (d) The distance separating the two gaps is now increased. State what happens to the path difference to the second order maximum. Justify your answer. [Turn over 2 Page 26 MARKS DO NOT WRITE IN THIS MARGIN 10. Retroflective materials reflect light to enhance the visibility of clothing. One type of retroflective material is made from small glass spheres partially embedded in a silver-coloured surface that reflects light. A ray of monochromatic light follows the path shown as it enters one of the glass spheres. normal ray of light air normal silver-coloured surface glass sphere 36° 18° 18° P (a) Calculate the refractive index of the glass for this light. Space for working and answer 3 Page 27 MARKS DO NOT WRITE IN THIS MARGIN 10. (continued) (b) Calculate the critical angle for this light in the glass. Space for working and answer (c) The light is reflected at point P. Complete the diagram below to show the path of the ray as it passes through the sphere and emerges into the air. normal ray of light air normal silver-coloured surface glass sphere 36° 18° 18° P (An additional diagram, if required, can be found on Page 38.) [Turn over 3 1 Page 28 MARKS DO NOT WRITE IN THIS MARGIN 11. A student is describing how the following circuit works. The student states: “The electricity comes out of the battery with energy and flows through the resistor using up some of the energy, it then goes through the LED and the rest of the energy is changed into light waves.” Use your knowledge of physics to comment on this statement. 3 Page 29 MARKS DO NOT WRITE IN THIS MARGIN 12. A technician sets up a circuit as shown, using a car battery and two identical lamps. The battery has an e.m.f. of 12·8 V and an internal resistance of 0·10 Ω. A V S 12·8 V 0·10 Ω 4·8 Ω (a) Switch S is open. The reading on the ammeter is 1·80 A. (i) Determine the reading on the voltmeter. Space for working and answer (ii) Switch S is now closed. State the effect this has on the reading on the voltmeter. Justify your answer. 4 3 [Turn over Page 30 MARKS DO NOT WRITE IN THIS MARGIN 12. (continued) (b) Some cars use LEDs in place of filament lamps. An LED is made from semiconductor material that has been doped with impurities to create a p-n junction. The diagram represents the band structure of an LED. conduction band valence band band gap p-type n-type (i) A voltage is applied across an LED so that it is forward biased and emits light. Using band theory, explain how the LED emits light. 3 Page 31 MARKS DO NOT WRITE IN THIS MARGIN 12. (b) (continued) (ii) The energy gap between the valence band and conduction band is known as the band gap. The band gap for the LED is 3·03 × 10−19 J (A) Calculate the wavelength of the light emitted by the LED. Space for working and answer (B) Determine the colour of the light emitted by the LED. [Turn over 4 1 Page 32 MARKS DO NOT WRITE IN THIS MARGIN 13. A technician sets up a circuit as shown. 150 mF 56 Ω 19 Ω 12 V + − P Q The power supply has negligible internal resistance. (a) The capacitor is initially uncharged. The switch is moved to position P and the capacitor charges. (i) State the potential difference across the capacitor when it is fully charged. (ii) Calculate the maximum energy stored by the capacitor. Space for working and answer 1 3 Page 33 MARKS DO NOT WRITE IN THIS MARGIN 13. (continued) (b) The switch is now moved back to position Q. Determine the maximum discharge current in the circuit. Space for working and answer (c) The technician replaces the 150 mF capacitor with a capacitor of capacitance 47 mF. The switch is moved to position P and the capacitor is fully charged. The switch is now moved to position Q. State the effect that this change has on the time the lamp stays lit. You must justify your answer. [Turn over for next question 3 2 Page 34 MARKS DO NOT WRITE IN THIS MARGIN 14. A student investigates the factors affecting the frequency of sound produced by a vibrating guitar string. The guitar string is stretched over two supports and is made to vibrate as shown. support not to scale guitar string pulley masses The frequency f of the sound produced by the vibrating string is given by the relationship 1 2 T f L μ = where T is the tension in the string L is the distance between the supports μ is the mass per unit length of the string. (a) The tension in the string is 49·0 N and the mass per unit length of the string is 4·00 × 10−4 kg m−1. The distance between the supports is 0·550 m. Calculate the frequency f of the sound produced. Space for working and answer 2 Page 35 MARKS DO NOT WRITE IN THIS MARGIN 14. (continued) (b) The guitar string in part (a) is replaced by a different guitar string. A student varies the tension T and measures the frequency f of the sound produced by the new guitar string. The student records the following information. T (N) T (N½) f (Hz) 10 3·2 162 15 3·9 190 20 4·5 220 25 5·0 254 30 5·5 273 (i) Using the square-ruled paper on Page 36, draw a graph of f against T (ii) Use your graph to determine the frequency of the sound produced when the tension in the guitar string is 22 N. [END OF QUESTION PAPER] 3 1 Page 36 Page 37 Page 38 MARKS DO NOT WRITE IN THIS MARGIN ADDITIONAL SPACE FOR ANSWERS AND ROUGH WORK Question 1 (d) displacement (m) time (s) sh 0 Question 7 (c) path of electron beam 0 V + 250 V Question 10 (c) normal ray of light air normal silver-coloured surface glass sphere 36° 18° 18° P Page 39 MARKS DO NOT WRITE IN THIS MARGIN ADDITIONAL SPACE FOR ANSWERS AND ROUGH WORK Page 40 MARKS DO NOT WRITE IN THIS MARGIN ADDITIONAL SPACE FOR ANSWERS AND ROUGH WORK ACKNOWLEDGEMENT Section 2 Question 10 – Image of Reflective Safety Jacket, taken from http://www.tradeget. com/listing/sri-balaji-associates/product-services-detail-62668/18652/1/1). SQA has made every effort to trace the owners of copyright materials reproduced in this question paper, and seek permissions. We will be happy to incorporate any missing acknowledgements. Please contact Janine.Anderson@sqa.org.uk. © National Qualications 2016 H X757/76/11 Physics Relationships Sheet TUESDAY, 24 MAY 9:00 AM – 11:30 AM A/PB Page 02 d vt = W = QV 2 peak rms V = V s vt = 2 E = mc 2 peak rms I = I v u at = + E hf = Q It = 2 1 2 s ut at = + 0 k E = hf hf − V = IR 2 2 2 v u as = + 2 1 E E hf − = 2 2 V P = IV = I R = R ( ) 1 2 s u v t = + 1 T f = 1 2 T R = R R . . . . + + W = mg F ma = v f = λ 1 2 1 1 1 T = . . . . R R R + + W E Fd = sin d = m θ λ E = V Ir + p E mgh = 1 2 sin sin n = θ θ E P t = 1 1 1 2 2 2 sin sin v = = v θ λ θ λ 1 1 2 2 V R = V R p = mv 1 sin c = n θ Q C = V Ft mv mu = − 1 2 2 m m F r = G 2 k I d = 2 2 1 1 1 2 2 2 Q E QV = CV = C = ( ) ' 1 t t vc − 2 = P I = A ( ) 2 ' 1 v l l c − = 2 1 2 k E = mv observed rest rest z − = λ λ λ v z c = 0 v H d = − max. min. value value random uncertainty = number of values 1 2   + =     path difference = m m m λ λ or where 0, 1, 2 . . . Relationships required for Physics Higher 1 1 1 2 s R V = V R R ⎛ ⎞ ⎜ ⎟ + ⎝ ⎠ o s s v f f v v ⎛ ⎞ ⎜ ⎟ ± ⎝ ⎠ = Page 03 Additional Relationships Circle circumference = 2πr area = πr2 Sphere area = 4πr2 volume = 4 3¯πr3 Trigonometry sin ϴ = opposite hypotenuse cos ϴ = adjacent hypotenuse tan ϴ = opposite adjacent sin2 ϴ + cos2 ϴ = 1 Page 04 Electron Arrangements of Elements Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 0 (1) (18) 1 H 1 Hydrogen Key Atomic number Symbol Electron arrangement Name 2 He 2 Helium (13) (14) (15) (16) (17) (2) 3 Li 2,1 Lithium 4 Be 2,2 Beryllium 5 B 2,3 Boron 6 C 2,4 Carbon 7 N 2,5 Nitrogen 8 O 2,6 Oxygen 9 F 2,7 Fluorine 10 Ne 2,8 Neon 11 Na 2,8,1 Sodium 12 Mg 2,8,2 Magnesium Transition Elements 13 Al 2,8,3 Aluminium 14 Si 2,8,4 Silicon 15 P 2,8,5 Phosphorus 16 S 2,8,6 Sulfur 17 Cl 2,8,7 Chlorine 18 Ar 2,8,8 Argon (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) 19 K 2,8,8,1 Potassium 20 Ca 2,8,8,2 Calcium 21 Sc 2,8,9,2 Scandium 22 Ti 2,8,10,2 Titanium 23 V 2,8,11,2 Vanadium 24 Cr 2,8,13,1 Chromium 25 Mn 2,8,13,2 Manganese 26 Fe 2,8,14,2 Iron 27 Co 2,8,15,2 Cobalt 28 Ni 2,8,16,2 Nickel 29 Cu 2,8,18,1 Copper 30 Zn 2,8,18,2 Zinc 31 Ga 2,8,18,3 Gallium 32 Ge 2,8,18,4 Germanium 33 As 2,8,18,5 Arsenic 34 Se 2,8,18,6 Selenium 35 Br 2,8,18,7 Bromine 36 Kr 2,8,18,8 Krypton 37 Rb 2,8,18,8,1 Rubidium 38 Sr 2,8,18,8,2 Strontium 39 Y 2,8,18,9,2 Yttrium 40 Zr 2,8,18, 10,2 Zirconium 41 Nb 2,8,18, 12,1 Niobium 42 Mo 2,8,18,13, 1 Molybdenum 43 Tc 2,8,18,13, 2 Technetium 44 Ru 2,8,18,15, 1 Ruthenium 45 Rh 2,8,18,16, 1 Rhodium 46 Pd 2,8,18, 18,0 Palladium 47 Ag 2,8,18, 18,1 Silver 48 Cd 2,8,18, 18,2 Cadmium 49 In 2,8,18, 18,3 Indium 50 Sn 2,8,18, 18,4 Tin 51 Sb 2,8,18, 18,5 Antimony 52 Te 2,8,18, 18,6 Tellurium 53 I 2,8,18, 18,7 Iodine 54 Xe 2,8,18, 18,8 Xenon 55 Cs 2,8,18,18, 8,1 Caesium 56 Ba 2,8,18,18, 8,2 Barium 57 La 2,8,18,18, 9,2 Lanthanum 72 Hf 2,8,18,32, 10,2 Hafnium 73 Ta 2,8,18, 32,11,2 Tantalum 74 W 2,8,18,32, 12,2 Tungsten 75 Re 2,8,18,32, 13,2 Rhenium 76 Os 2,8,18,32, 14,2 Osmium 77 Ir 2,8,18,32, 15,2 Iridium 78 Pt 2,8,18,32, 17,1 Platinum 79 Au 2,8,18, 32,18,1 Gold 80 Hg 2,8,18, 32,18,2 Mercury 81 Tl 2,8,18, 32,18,3 Thallium 82 Pb 2,8,18, 32,18,4 Lead 83 Bi 2,8,18, 32,18,5 Bismuth 84 Po 2,8,18, 32,18,6 Polonium 85 At 2,8,18, 32,18,7 Astatine 86 Rn 2,8,18, 32,18,8 Radon 87 Fr 2,8,18,32, 18,8,1 Francium 88 Ra 2,8,18,32, 18,8,2 Radium 89 Ac 2,8,18,32, 18,9,2 Actinium 104 Rf 2,8,18,32, 32,10,2 Rutherfordium 105 Db 2,8,18,32, 32,11,2 Dubnium 106 Sg 2,8,18,32, 32,12,2 Seaborgium 107 Bh 2,8,18,32, 32,13,2 Bohrium 108 Hs 2,8,18,32, 32,14,2 Hassium 109 Mt 2,8,18,32, 32,15,2 Meitnerium 110 Ds 2,8,18,32, 32,17,1 Darmstadtium 111 Rg 2,8,18,32, 32,18,1 Roentgenium 112 Cn 2,8,18,32, 32,18,2 Copernicium 57 La 2,8,18, 18,9,2 Lanthanum 58 Ce 2,8,18, 20,8,2 Cerium 59 Pr 2,8,18,21, 8,2 Praseodymium 60 Nd 2,8,18,22, 8,2 Neodymium 61 Pm 2,8,18,23, 8,2 Promethium 62 Sm 2,8,18,24, 8,2 Samarium 63 Eu 2,8,18,25, 8,2 Europium 64 Gd 2,8,18,25, 9,2 Gadolinium 65 Tb 2,8,18,27, 8,2 Terbium 66 Dy 2,8,18,28, 8,2 Dysprosium 67 Ho 2,8,18,29, 8,2 Holmium 68 Er 2,8,18,30, 8,2 Erbium 69 Tm 2,8,18,31, 8,2 Thulium 70 Yb 2,8,18,32, 8,2 Ytterbium 71 Lu 2,8,18,32, 9,2 Lutetium 89 Ac 2,8,18,32, 18,9,2 Actinium 90 Th 2,8,18,32, 18,10,2 Thorium 91 Pa 2,8,18,32, 20,9,2 Protactinium 92 U 2,8,18,32, 21,9,2 Uranium 93 Np 2,8,18,32, 22,9,2 Neptunium 94 Pu 2,8,18,32, 24,8,2 Plutonium 95 Am 2,8,18,32, 25,8,2 Americium 96 Cm 2,8,18,32, 25,9,2 Curium 97 Bk 2,8,18,32, 27,8,2 Berkelium 98 Cf 2,8,18,32, 28,8,2 Californium 99 Es 2,8,18,32, 29,8,2 Einsteinium 100 Fm 2,8,18,32, 30,8,2 Fermium 101 Md 2,8,18,32, 31,8,2 Mendelevium 102 No 2,8,18,32, 32,8,2 Nobelium 103 Lr 2,8,18,32, 32,9,2 Lawrencium Lanthanides Actinides