OCR A-Level Physics 2027 Predicted Practice Paper — Modelling Physics

Answer ALL questions. Write your answers in the spaces provided. You must write down all the stages in your working.

Section A

Multiple choice. Answer ALL the questions.

• 1

  Question SECTION-A1 (1 mark)

  Which of the following is an SI base unit?

  A. newtonB. coulombC. moleD. watt

  (Total for Question SECTION-A1 is 1 mark)
• 2

  Question SECTION-A2 (1 mark)

  A car travels 300 m due east in 20 s, then 400 m due north in 30 s. What is the magnitude of its average velocity for the whole journey?

  A. 10 m/sB. 14 m/sC. 20 m/sD. 28 m/s

  (Total for Question SECTION-A2 is 1 mark)
• 3

  Question SECTION-A3 (1 mark)

  A resultant force of 12 N acts on a body of mass 3.0 kg initially at rest. What is its kinetic energy after it has moved 4.0 m in the direction of the force?

  A. 16 JB. 24 JC. 36 JD. 48 J

  (Total for Question SECTION-A3 is 1 mark)
• 4

  Question SECTION-A4 (1 mark)

  A wire obeys Hooke's law. If both its original length and its cross-sectional area are doubled while the same tension is applied, how does its extension change compared with the original?

  A. HalvedB. UnchangedC. DoubledD. Quadrupled

  (Total for Question SECTION-A4 is 1 mark)
• 5

  Question SECTION-A5 (1 mark)

  The resistance of a metallic conductor at constant temperature is measured. Which graph of current I (y-axis) against potential difference V (x-axis) is obtained?

  A. A straight line through the originB. A curve of decreasing gradientC. A curve of increasing gradientD. A horizontal straight line

  (Total for Question SECTION-A5 is 1 mark)
• 6

  Question SECTION-A6 (1 mark)

  Two resistors of 6.0 ohm and 3.0 ohm are connected in parallel, and this combination is connected in series with a 4.0 ohm resistor. What is the total resistance?

  A. 2.0 ohmB. 6.0 ohmC. 9.0 ohmD. 13 ohm

  (Total for Question SECTION-A6 is 1 mark)
• 7

  Question SECTION-A7 (1 mark)

  A progressive wave has frequency 250 Hz and travels at 340 m/s. What is the phase difference between two points 0.34 m apart along the direction of travel?

  A. pi/4 radB. pi/2 radC. pi radD. 2 pi rad

  (Total for Question SECTION-A7 is 1 mark)
• 8

  Question SECTION-A8 (1 mark)

  Light of a single wavelength passes through a double slit and produces fringes on a screen. If the slit separation is increased, what happens to the fringe spacing?

  A. It increasesB. It decreasesC. It stays the sameD. The fringes disappear

  (Total for Question SECTION-A8 is 1 mark)
• 9

  Question SECTION-A9 (1 mark)

  A photon of frequency f has momentum p. Which expression correctly gives p?

  A. hfB. hf/cC. hc/fD. h/(cf)

  (Total for Question SECTION-A9 is 1 mark)
• 10

  Question SECTION-A10 (1 mark)

  An object performs simple harmonic motion. At which point in the cycle is its acceleration a maximum and its velocity zero?

  A. At the equilibrium positionB. At maximum displacementC. At half the amplitudeD. At the point of maximum kinetic energy

  (Total for Question SECTION-A10 is 1 mark)
• 11

  Question SECTION-A11 (1 mark)

  A satellite is in a circular orbit around a planet. If the orbital radius is increased to four times its original value, by what factor does the orbital speed change?

  A. Multiplied by 1/4B. Multiplied by 1/2C. Multiplied by 2D. Multiplied by 4

  (Total for Question SECTION-A11 is 1 mark)
• 12

  Question SECTION-A12 (1 mark)

  A capacitor is charged and then discharged through a fixed resistor. The time constant of the circuit is 5.0 s. After how long does the charge fall to 1/e of its initial value?

  A. 1.8 sB. 3.5 sC. 5.0 sD. 10 s

  (Total for Question SECTION-A12 is 1 mark)
• 13

  Question SECTION-A13 (1 mark)

  An electron enters a uniform magnetic field at right angles to the field lines. Which statement best describes its subsequent motion (ignoring energy loss)?

  A. It moves in a straight line at constant speedB. It moves in a circular path at constant speedC. It moves in a parabolic pathD. It slows down and stops

  (Total for Question SECTION-A13 is 1 mark)
• 14

  Question SECTION-A14 (1 mark)

  The activity of a radioactive source falls from 800 Bq to 100 Bq in 12 hours. What is the half-life of the source?

  A. 2.0 hoursB. 3.0 hoursC. 4.0 hoursD. 6.0 hours

  (Total for Question SECTION-A14 is 1 mark)
• 15

  Question SECTION-A15 (1 mark)

  Which of the following is the correct representation of the beta-minus decay of a free neutron?

  A. n -> p + electron + electron neutrinoB. n -> p + electron + electron antineutrinoC. n -> p + positron + electron neutrinoD. n -> p + positron + electron antineutrino

  (Total for Question SECTION-A15 is 1 mark)

Section B

Structured and extended response questions. Answer ALL the questions.

• 1

  Question SECTION-B1 (8 marks)

  A ball is projected from ground level with a speed of 24 m/s at an angle of 30 degrees above the horizontal. Take g = 9.81 m/s^2 and ignore air resistance. (a) Show that the initial vertical component of velocity is about 12 m/s. (1) (b) Calculate the time the ball spends in the air before returning to ground level. (2) (c) Calculate the horizontal range of the ball. (2) (d) State and explain how the actual range would differ if air resistance were significant. (3)

  (Total for Question SECTION-B1 is 8 marks)
• 2

  Question SECTION-B2 (7 marks)

  A vertical steel wire of original length 2.5 m and diameter 0.40 mm hangs from a fixed support. A load creating a tension of 120 N is applied and the wire extends by 1.8 mm. The wire remains within its elastic limit. (a) Calculate the cross-sectional area of the wire. (2) (b) Calculate the stress in the wire. (2) (c) Calculate the Young modulus of the steel. (2) (d) The elastic strain energy stored in the wire is released when the load is removed. Calculate the energy stored, assuming the wire obeys Hooke's law. (1)

  (Total for Question SECTION-B2 is 7 marks)
• 3

  Question SECTION-B3 (8 marks)

  A student investigates a filament lamp connected to a variable power supply. (a) Sketch the current-voltage (I-V) characteristic of a filament lamp, with I on the vertical axis, for both positive and negative voltages. (2) (b) Explain, in terms of the behaviour of the metal filament, why the characteristic has the shape you have drawn. (3) (c) At an operating point the lamp draws 0.45 A at 6.0 V. Calculate the resistance of the filament at this point and the power dissipated. (3)

  (Total for Question SECTION-B3 is 8 marks)
• 4

  Question SECTION-B4 (7 marks)

  A copper connecting wire has length 15 m and diameter 1.2 mm. The resistivity of copper is 1.7e-8 ohm m. (a) Calculate the resistance of the wire. (3) (b) The wire carries a current of 3.0 A. Calculate the potential difference across its ends. (1) (c) The wire is replaced by an aluminium wire of the same length and same resistance. Aluminium has a higher resistivity than copper. State and explain how the diameter of the aluminium wire must compare with that of the copper wire. (3)

  (Total for Question SECTION-B4 is 7 marks)
• 5

  Question SECTION-B5 (8 marks)

  Monochromatic ultraviolet radiation of wavelength 180 nm is incident on a clean metal surface whose work function is 2.9 eV. Take h = 6.63e-34 J s, c = 3.00e8 m/s and 1 eV = 1.60e-19 J. (a) State what is meant by the work function of a metal. (1) (b) Calculate the energy of a single photon of this radiation, in joules. (2) (c) Calculate the maximum kinetic energy of the emitted photoelectrons, in joules. (2) (d) The intensity of the radiation is doubled while the wavelength is unchanged. State and explain the effect on (i) the maximum kinetic energy of the photoelectrons and (ii) the rate of emission of photoelectrons. (3)

  (Total for Question SECTION-B5 is 8 marks)
• 6

  Question SECTION-B6 (8 marks)

  A small mass of 0.25 kg is attached to a light string and whirled in a horizontal circle of radius 0.80 m at a steady rate of 2.5 revolutions per second. (For this part treat the string as horizontal.) (a) Calculate the angular velocity of the mass. (2) (b) Calculate the centripetal force required. (2) (c) Calculate the linear speed of the mass. (1) (d) In practice the string cannot be exactly horizontal. Explain why, with reference to the forces acting on the mass. (3)

  (Total for Question SECTION-B6 is 8 marks)
• 7

  Question SECTION-B7 (9 marks)

  A satellite orbits the Earth in a circular path of radius 8.0e6 m from the Earth's centre. Take G = 6.67e-11 N m^2 kg^-2 and the mass of the Earth M = 5.97e24 kg. (a) Explain why a gravitational field is described as radial around the Earth, and state how the field strength varies with distance. (2) (b) Show that the orbital speed of the satellite is about 7.1e3 m/s. (2) (c) Calculate the period of the orbit. (3) (d) A second satellite is placed in a geostationary orbit. State two conditions that a geostationary orbit must satisfy. (2)

  (Total for Question SECTION-B7 is 9 marks)
• 8

  Question SECTION-B8 (6 marks)

  A 470 microfarad capacitor is charged to a potential difference of 12 V and then discharged through a 22 kilo-ohm resistor. (a) Calculate the energy stored in the fully charged capacitor. (2) (b) Calculate the time constant of the discharge circuit. (1) (c) Calculate the time taken for the potential difference across the capacitor to fall to 3.0 V. (3)

  (Total for Question SECTION-B8 is 6 marks)
• 9

  Question SECTION-B9 (8 marks)

  A fixed mass of an ideal gas occupies a volume of 0.020 m^3 at a pressure of 1.2e5 Pa and a temperature of 290 K. Take R = 8.31 J mol^-1 K^-1, the Avogadro constant N_A = 6.02e23 mol^-1, the Boltzmann constant k = 1.38e-23 J/K and the mass of one gas molecule = 4.65e-26 kg. (a) Calculate the number of moles of gas present. (2) (b) Calculate the number of molecules present. (1) (c) Calculate the root-mean-square speed of the molecules at 290 K. (2) (d) The gas is heated at constant volume. Using kinetic theory, explain why the pressure of the gas increases. (3)

  (Total for Question SECTION-B9 is 8 marks)
• 10

  Question SECTION-B10 (8 marks)

  A coil of 240 turns and cross-sectional area 3.0e-3 m^2 is placed with its plane perpendicular to a uniform magnetic field. The magnetic flux density is reduced uniformly from 0.50 T to zero in a time of 0.15 s. (a) State Faraday's law of electromagnetic induction. (1) (b) Calculate the initial magnetic flux through one turn of the coil. (1) (c) Calculate the magnitude of the average e.m.f. induced in the coil during the change. (3) (d) State Lenz's law and explain how it is consistent with the principle of conservation of energy. (3)

  (Total for Question SECTION-B10 is 8 marks)
• 11

  Question SECTION-B11 (8 marks)

  The helium-4 nucleus has a mass defect of 0.0304 u. Take 1 u = 931.5 MeV/c^2 and 1 u = 1.66e-27 kg. (a) Explain what is meant by the mass defect of a nucleus. (1) (b) Calculate the binding energy of the helium-4 nucleus in MeV. (2) (c) Calculate the binding energy per nucleon in MeV. (1) (d) A sketch of binding energy per nucleon against nucleon number rises steeply, peaks near iron, then falls slowly. Using this shape, explain why energy is released in both nuclear fusion of light nuclei and nuclear fission of heavy nuclei. (4)

  (Total for Question SECTION-B11 is 8 marks)