SCGS 2025 PHY PRELIM P3 QP

1 SINGAPORE CHINESE GIRLS’ SCHOOL PRELIMINARY EXAMINATION SECONDARY FOUR CANDIDATE NAME CLASS REGISTER NUMBER PHYSICS 6091/03 Paper 3 30 July 2025 1 hour 50 minutes Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRST Write your name, register number and class on all the work you hand in. Give details of the practical shift and laboratory in the boxes provided. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction tape. Answer all questions in the spaces provided on the Question Paper: scrap paper must not be used. Graph paper is provided in this Question Paper. You will be allowed to work with the apparatus for a maximum of 55 minutes for each section. You are expected to record all your observations as soon as they are made. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. At the end of the practical, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. This question paper consists of 17 printed pages and 3 blank pages. Shift Laboratory For Examiner’s Use 1 / 10 2 / 10 3 / 20 Total / 40 4

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3 1 In this experiment, you will investigate the force needed to pull a cylinder up a step. You are provided with: ▪ a half-metre rule ▪ a digital caliper ▪ a newton meter ▪ two 100 g slotted masses ▪ a loop of thread (a) Measure and record the thickness h of the half-metre rule, as shown in Fig. 1.1. Fig. 1.1 h = ……………………………… [1] (b) (i) Suspend the two slotted masses from the newton meter using the loop of thread as shown in Fig. 1.2. Fig. 1.2 (ii) Measure and record the total weight W of these masses. W = ……………………………… [1] half-metre rule

4 (c) Measure and record the diameter d of one of the slotted masses. Determine the radius r of this slotted mass. d = ……………………………… r = ……………………………… [1] (d) (i) Place the half-metre rule on the bench. Stand two slotted masses on their edges next to one end of the rule, with their slots at the top, as shown in Fig. 1.3. Attach the loop of thread to the masses and the newton meter, as shown in Fig. 1.3. Fig. 1.3 Pull the handle of the newton meter horizontally and at right angles to the step. The force required to just start the slotted masses rolling up the step is F. Measure and record F. F = ……………………………… [1] (ii) Determine the angle α, given by –()sin = rhα r α = ……………………………… [1] half-metre rule slot

5 Plan It is suggested that F, W and α are related by the equation F = kW tan α where k is a constant. You are to plan an experiment to investigate the above relationship. You can also use other apparatus and materials that are usually available in a school laboratory. Your plan should include: ▪ the independent and dependent variables, ▪ the quantities that you will be keeping constant in the investigation, ▪ a detailed description of how you will perform the investigation, ▪ an indication of how you will achieve accurate results, ▪ explanation on how to use the readings to reach the conclusion. A diagram is not required but you may draw one if it helps in your explanation. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………..

6 ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ………………..……………………………………………………………………………………………[5] [ Total : 10 m ]

7 2 In this experiment, you will determine the focal length of a semicircular block using two methods. You are provided with ▪ a transparent semicircular block ▪ a protractor ▪ a half-metre rule ▪ a digital caliper ▪ a piece of paper labelled P ▪ a corkboard ▪ 3 optical pins METHOD 1 (a) Take measurements to determine the radius of curvature R of the curved surface, as shown in Fig. 2.1. Fig. 2.1 R = ……………………………… [1] (b) (i) A piece of paper labelled P, with four parallel lines drawn on it, is provided. Measure and record lengths A and B. A = ……………………………… B = ……………………………… Calculate E using = BE A E = ……………………………… [1] R

8 (ii) Arrange the apparatus as shown in Fig. 2.2. Fig. 2.2 Look down through the block and close one eye. The appearance of the lines should be similar to Fig. 2.3. Fig. 2.3 Gradually raise the block until the two central lines seen through the block are aligned with the two outer lines seen outside the block, as shown in Fig. 2.4. You may have to move your head sideways to see this alignment. Fig. 2.4 observer block paper P bench block

9 With the block in this position, measure and record the height d1 of the block above the paper, as shown in Fig. 2.5. Fig. 2.5 d1 = ……………………………… cm [1] (iii) Turn the block over and place the curved face onto the paper. Look down through the block with one eye. Gradually raise the block until the two central lines seen through the block are aligned with the two outer lines seen outside the block. Measure and record the height d2 of the block above the paper, as shown in Fig. 2.6. Fig. 2.6 d2 = ……………………………… cm [1] d 1 d 2

10 (c) It is suggested that the relationship between R, d1 and d2 is 2k = R + d1 – d2 where k is a constant. Using your data, calculate k. Give the appropriate unit. k = ……………………………… [1] (d) The focal length f of the block is given by 2( + ) = ( -1) E d kf E Calculate the value of f. Give the appropriate unit. f = ……………………………… [1]