PRCSS Prelim P2

[Turn over PASIR RIS CREST SECONDARY SCHOOL Preliminary Examination Secondary Four Express CANDIDATE NAME CLASS / INDEX NUMBER Physics 6091/02Paper 2 20 August 2024 1 hour 45 minutesCandidates answer on the Question Paper No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. Candidates are reminded that all quantitative answers should include appropriate units. The use of an approved scientific calculator is expected, where appropriate. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of Physics than for correct answers. The total number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 80 Parent’s Signature This document consists of 18 printed pages.

2 SECTION A Answer all questions. 1 An airplane, of mass 250 000 kg, is traveling at an altitude of 12 000 m. The airplane encounters severe air turbulence at t = 40 s and experiences rapid ascents and descents. Fig. 1.1 shows the vertical velocity-time graph for the airplane. Fig. 1.1 (a) Describe the vertical forces acting on the airplane at t = 20 s. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. . [2] (b) Determine the upward force acting on the airplane at t = 46 s. The gravitational field strength is 10 N/kg. upward force = ……………………… [3] (c) Determine the change in the vertical displacement of the airplane from t = 40 s to 85 s. change in vertical displacement = ……………………… [2] [Total: 7] 2.0 −4.0 vertical velocity m/s 4.0 −2.0 20 40 60 80 time / s 100 0 0

3 [Turn over 2 Fig. 2.1 shows a simple hydraulic press. Fig. 2.1 A force of 100 N pushes piston 1, which has a cross-sectional area of 10 cm2, downwards by 20 cm. Piston 2, which has a cross-sectional area of 50 cm2, moves upwards as a result. (a) Define pressure. ………………………………………………………………………………………………….. [1] (b) Calculate (i) the force exerted on piston 2, force = ……………………… [2] (ii) the distance moved by piston 2. distance = ……………………… [2] (c) Explain why the simple hydraulic press does not work if the liquid is replaced by a gas. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. [1] [Total: 6] piston 2 piston 1 liquid

4 3 Fig. 3.1 shows an unused glass cup with a metal handle. Fig. 3.1 A boy touches the glass cup and then the metal handle. (a) Explain why the boy feels that the metal handle is cooler than the glass cup. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. [2] (b) Describe, in microscopic terms, how conduction occurs in within the glass. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. [2] (c) 150 g of water at 30 °C is poured into the glass cup. 50 g of ice cubes at –5 °C are then added to the water. The specific heat capacity of ice is 2.1 J/(g °C). The specific heat capacity of water is 4.2 J/(g °C). The specific latent heat of fusion of water is 330 J/g. Assume all energy transfer is between the water and the ice. (i) On Fig. 3.2, draw a heating curve to show the change in kinetic energy of the particles of the ice cubes till the energy transfer is completed. Fig. 3.2 [1] (ii) Calculate the final temperature of the water. temperature = ……………………… [3] [Total: 8] metal handle glass cup kinetic energy time

5 [Turn over 4 Ultraviolet light is part of the electromagnetic spectrum. (a) Ultraviolet light enables us to produce vitamin D for our bones, muscles and immune system. Describe another use of ultraviolet light. …………………………………………..……………………………………………………… ……………………………………………………………………………………..…………… [1] (b) Over-exposure to ultraviolet light can cause heating effects and ionising effects. Describe the ionising effects on living cells. …………………………………………..……………………………………………………… ……………………………………………………………………………………..…………… …………………………………………………………………………..……………………… …………………………………………………………………………..……………………… [2] (c) The wavelength of ultraviolet light is roughly 100 times larger than the size of an atom. (i) Estimate the wavelength of ultraviolet light. …………………………………………………………………………………………… [1] (ii) Calculate the frequency of the ultraviolet light in (i). State the value of any constant used. frequency = ……………………… [2] [Total: 6]

6 5 Fig. 5.1 shows an electrostatic precipitator removing dirt particles suspended in the dirty gas. Fig. 5.1 (a) State the type of charges on the dirt particles after they come into contact with the negatively charged wire. ………………………………………………………………………………………………….. [1] (b) Describe and explain how the charged dirt particles from the dirty gas are removed from the electrostatic precipitator. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. [3] [Total: 4] dirty gas in clean gas out dirt particles out + − weight negatively charged wire cover metal body

7 [Turn over 6 Fig. 6.1 shows a current-carrying solenoid. The directions of current, I, entering and leaving the solenoid are shown. Fig. 6.1 (a) On Fig. 6.1, draw the magnetic field of the current-carrying solenoid. [1] (b) State the instrument to determine the direction of the magnetic field at point P. ………………………………………………………………………………………………….. [1] (c) Some iron nails are placed near but not in contact with the current-carrying solenoid. Describe and explain, in terms of induced magnetism, what happens to the iron nails. ………………………………………………………………………………………………….. ………………………………………………………………………………………………….. [2] (d) The current flowing to the solenoid is cut off. Explain what happens to the iron nails. ………………………………………………………………………………………………….. [1] [Total: 5] I I P

8 7 Fig. 7.1 shows a dc motor. Fig. 7.1 (a) State the direction of rotation of the coil. …………………………………………………………………………………………..……… [1] (b) Explain why the coil experiences a turning effect. ……………………………………………………………………………………………..…… ………………………………………………………………………………………………..… ………………………………………………………………………………………………..… [2] (c) The turning effect can be increased by adding a soft iron cylinder into the core of the coil. Explain how the soft iron increases the turning effect. ………………………………………………………………………………………………..… ……………………………………………………………………………………………..…… ………………………………………………………………………………………………..… [2] (d) State how the split-ring commutator ensures the coil rotates in one direction continuously. ………………………………………………………………………………………………..… [1] [Total: 6] S N

9 [Turn over 8 (a) An experiment on electromagnetic induction can be used to show that the direction of the induced