Bukit Merah Prelim P2

Class Index Number Name BUKIT MERAH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS PHYSICS 6091/02 Paper 2 Theory 19 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No additional material is required. READ THESE INSTRUCTIONS FIRST Write your class, index number and name 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. Section B Answer one question. 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 number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 24 printed pages. Setter: Mrs Goh SM [Turn over

2 BMSS/2024/4E/PRELIM/6091/02 [Turn over Section A (70 marks) Answer all the questions in this section. 1 Fig. 1.1 shows a bird cage hanging on a uniform wooden pole of length 1.8 m and mass 10 kg. The pole is kept horizontal by two ropes, A and B, each tied at the ends of the pole. The bird and the cage have a total mass of 6.0 kg and is suspended 1.2 m away from rope A. The gravitational field strength g is 10 N/kg. (a) Using the principle of moments or otherwise, calculate the tension in rope A and B. tension is rope A = …………………………. tension is rope B = …………………………. [3] (b) The bird keeper wants to suspend another bird cage of weight 30 N on the pole without increasing the tension in rope B as he is afraid rope B will snap. Suggest and explain where he should suspend this second bird cage. …………………………………………………………………………………………………………….. …………………………………………………………………………………………….…………....[2] [Total:5] Fig. 1.1 bird and cage ceiling rope B rope A wooden pole 1.2 m Fig. 1.1

3 BMSS/2024/4E/PRELIM/6091/02 [Turn over 2 A set-up consists of a syringe and a manometer connected to each end of a pipe can be used to detect leaks in the pipe. (a) Fig. 2.1 shows the levels of water on each side of the manometer after the piston is pushed down and left down and the air inside the syringe is pushed into the pipe. The atmospheric pressure is 100 kPa. The gravitational field strength is 10 N/kg and the density of water in the manometer is 1000 kg/m3. Calculate the air pressure inside the pipe. air pressure in pipe = …………………………….. [2] (b) If the pipe leaks very slowly, state what happens to the levels of water on each side of the manometer. You may add to Fig. 2.1 if it helps to explain your answer. …………………………………………………………………………………………………...…..……... ………………………………………………………………………………………….……………...…[1] Fig. 2.1 syringe air manometer water pipe air narrow tube narrow tube 100 mm 60 mm

4 BMSS/2024/4E/PRELIM/6091/02 [Turn over (c) Using ideas about molecules and pressure, explain you answer in (b). …………………………………………………………………………………………………………….… …………………………………………………………………………………………………..….………. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………..….…… [2] (d) Other than the toxicity of mercury, explain why mercury is not a suitable liquid to use in the manometer in this situation. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………..…….… [1] [Total:6] 3 The main parts of an electric grill are shown in Fig. 3.1. The heating element will glow red hot. Fig. 3.1 (a) Name the main process of energy transfer responsible for cooking the food. …………………………………………………………….…………………………………..…….….. [1] (b) A layer of shiny material is placed between the heating element and the top of the metal case of the grill. Explain one way in which it improves the function or design of the electric grill. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………..….…… [1] [Total:2]

5 BMSS/2024/4E/PRELIM/6091/02 [Turn over 4 A student poured 0.25 kg of hot tea into a container. At time t = 0 min, he placed a temperature sensor into the hot tea and started measuring the temperature of the tea. After a certain time, ice cubes were added to the hot tea. Fig. 4.1 shows the temperature-time graph obtained. The following information is provided. specific latent heat of fusion of ice 336 kJ/kg specific latent heat of vaporisation of water or tea 2260 kJ/kg specific heat capacity of ice 2100 J/(kgK) specific heat capacity of water or tea 4200 J/(kgK) Assume that there is no transfer of energy to the internal store of the surroundings when ice is added and the initial temperature of the ice-cubes is 0 oC. (a) State the time at which the student added the ice cubes into the hot tea. …………………………………………………………….…………………………………..…….….. [1] (b) Calculate the loss of energy from the internal store of the hot tea from B to C. loss of energy = …………………………… [1] Fig. 4.1 temp / oC time / min 5.0

6 BMSS/2024/4E/PRELIM/6091/02 [Turn over (c) Calculate the mass of the ice cubes added into the hot tea. Mass of ice cubes = …………………………… [2] (d) Explain in terms of molecules, how evaporation helps the hot tea to cool down. …………………………………………………………………………………………………………….… …………………………………………………………………………………………………..….………. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………..….…… [2] [Total:6]

7 BMSS/2024/4E/PRELIM/6091/02 [Turn over 5 Fig. 5.1 shows the path of ray X as it passes through a thin converging lens AB. An image is formed at Y. Fig. 5.1 (a) Determine the focal length of the lens AB. focal length = ………………………………. [1] (b) On Fig. 5.1, draw rays to show how the image is formed. Label the image, I. [2] (c) The image formed is real. State what is meant by real. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………..…….… [1] (d) State the name of a device that uses a converging lens to form an image as found in part (b). …………………………………………………………………………………………………..…….… [1] [Total:5] ABprincipal axisobject4.0 cm4.0 cmrayX A B Y

8 BMSS/2024/4E/PRELIM/6091/02 [Turn over 6 An engineer designs an ultrasound device that can be used to monitor the thickness of pipes as shown in Fig. 6.1. Fig. 6.1 The device emits an ultrasound pulse of frequency 4.0 x 106 Hz. The pulse travels through the wall of the metal