2025 CHIJ SEC (TP) Physics Prelim Paper 2 QP

This document consists of 22 printed pages and 2 blank pages. Name: ( ) Class: WHITLEY SECONDARY SCHOOL A Caring and Learning Community of Leaders Perseverance * Respect * Integrity * Discipline *Empathy PRELIMINARY EXAMINATION 2025 READ THESE INSTRUCTIONS FIRST Write your 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. Write your answers in the spaces provided. Section B Answer only 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 number of marks is given in brackets [ ] at the end of each question or part question. SUBJECT : PHYSICS PAPER 2 (6091/02) LEVEL : Sec 4 G3 DATE : 29 August 2025 DURATION : 1 hr 45 mins SETTER : Mr Krishan Sanjay VETTER : Ms Keira Htay For Examiner’s Use Section A / 70 Section B / 10 Total / 80

2 Section A Answer all the questions in this section. 1 Fig. 1.1 shows a rocket just after its launch. At its launch, the rocket and its contents have a total mass of 1.2 x 10 5 kg. Fig. 1.2 shows how the upward thrust on the rocket changes with time in the first 40 s after the launch. The gravitational field strength g is 10 N/kg. (a) Calculate the weight of the rocket just before its launch. weight = ………………………… [1] (b) At the point of launching, the rocket does not take off immediately. State the time when the rocket starts to take off and explain your answer. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [2]

3 (c) Calculate the acceleration of the rocket at t = 30 s. acceleration = ………………………… [2] (d) 30 s after launch, the total weight of the rocket and its content decreases significantly as fuel is being burnt off while the thrust remains the same. Describe the motion of the rocket after 30 s. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [1] 2 Fig. 2.1 shows an electric kettle and the live, neutral and earth wires of a household electricity supply. The kettle has a power rating of 2.0 kW. The supply voltage is 240 V. (a) Complete Fig. 2.1 to show how the kettle should be connected to the supply. Include a switch and a fuse in your drawing. Fig. 2.1 [2]

4 (b) The live wire becomes loose and touches the metal case. Explain why a person who later touches the case feels no shock and is not harmed. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [3] 3 Fig 3.1 shows a mercury manometer connected to a gas supply. Fig. 3.1 (a) Explain, using the kinetic model of matter, how the gas supply exerts a pressure. ………………………………………………….………………………………………… ………………………………………………….………………………………………… [1] (b) The atmospheric pressure is 74 cmHg. Determine the pressure of the gas supply. gas pressure = …………………………………… cmHg [1]

5 (c) Some air leaks into the closed end and the reading of the manometer changes to 78 cm. Determine the pressure within the closed end. pressure in the closed end = …………………………………… cmHg [2] 4 Fig. 4.1 shows a walking stick that has a metal head and a rubber foot. It balances on a pencil placed 0.50 m from its rubber foot. The walking stick has a total length of 0.80 m. Fig. 4.1 (a) (i) State the definition of centre of gravity. ………………………………………………….………………………………… [1] (ii) State the distance between the centre of gravity of the walking-stick and the end of the rubber foot. ………………………………………………….………………………………… [1]

6 (b) Fig 4.2 shows a truck of mass M of 5000 kg crossing a horizontal bridge of uniform mass m 1000 kg and length l of 100 m. The bridge is supported at its ends. Fig. 4.2 Calculate the forces R and S, acting on the bridge when the truck is one-third of the way across the bridge. Show your working clearly. R = ………………………… S = ………………………… [3] R S Wt Wb l / 3 bridge truck

7 5 Fig. 5.1 shows a section of a solar heating system which helps to provide hot water for a house. It consists of a solar panel placed outdoor on a roof. Connected to this panel are water pipes. Heat from the Sun warms the water in these pipes which is then pumped to a hot water tank inside the house. Inside the hot water tank, the hot water transfers its heat, becomes cooled and circulates back to the solar panel. Fig. 5.1 (a) Explain the purpose of the following features: (i) there is an insulation for the water pipe in the solar panel, and ………………………………………………….………………………………….. ………………………………………………….………………………………….. [1] (ii) the water pipe in the hot water tank is spiral and painted black. ………………………………………………….………………………………….. ………………………………………………….………………………………….. ………………………………………………….………………………………….. [2]

8 (b) In the hot water tank, the water enters at a higher temperature than the surrounding metal of the tank. Explain why the water eventually cools down. ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… [2] 6 Fig. 6.1 shows a rigid rectangular card which has a rectangular hole cut out in the centre. Fig. 6.2 shows the setup used to measure the acceleration of the card as it falls freely to the ground. A torchlight which is directed towards the light dependent resistor (LDR) is turned on. A computer is used to measure the potential difference across RS. Fig. 6.1 Fig 6.2

9 Fig. 6.3 shows the graph of potential difference (p.d.) across RS against time. Fig. 6.3 (a) State what happens to the resistance of the LDR as the card falls. ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… [2] (b) Explain why the p.d. across the variable resistor drops to 0.50 V. ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… [2]

10 (c) Explain why time interval 1 is longer than time interval 2 (as shown in Fig.6.3) when the rigid card falls. ………………………………………………….………………………………………… ………………………………………………….………………………………………… ………………………………………………….………………………………………… [2] 7 Fig. 7.1 shows the object and its image with ray X moving towards a converging lens. Fig. 7.1 (a) Draw, on Fig. 7.1, one ray to locate the focal point of the lens. Mark the focal point with the letter F. [1] (b) Determine the focal length of the lens in Fig. 7.1. focal length = ………………………… [1] (c) Complete the path for ray X on Fig. 7.1. [1]