2021 J2 H2 Physics Prelim P4

This paper consists of 21 printed pages p Anglo-Chinese Junior College Physics Preliminary Examination Higher 2 CANDIDATE NAME CLASS CENTRE NUMBER S 3 0 0 4 INDEX NUMBER PHYSICS Paper 4 Practical Candidates answer on the Question Paper. Additional Materials: As listed In the Confidential Instructions 9749/04 5 August 2021 2 hours 30 mins READ THESE INSTRUCTIONS FIRST Write your name and index number in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Answer all questions. Write your answers in the spaces provided on the question paper. 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 the appropriate units. Give details of your practical shift and laboratory, where appropriate, in the boxes provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. Shift Laboratory For Examiners’ use only 1 / 9 2 / 13 3 / 21 4 / 12 Total / 55

2 Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use 1 In this experiment, you will investigate the equilibrium of a metre rule. (a) (i) You have been provided with a metre rule with two springs attached. The distance between one end of the metre rule and the string is L, as shown in Fig. 1.1. Fig. 1.1 Measure and record L. L = …………………………….. [1] (ii) Calculate L n where n = 3. L n = ……………………………....

3 [Turn over Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use (b) (i) Set up the apparatus as shown in Fig. 1.2. Fig. 1.2 Adjust the apparatus until the horizontal distance between the centres of the rods of the clamps is equal to your value of L n . Adjust the heights of the bosses so that the rule is horizontal and the springs are vertical and unstretched when the rule is held in position. Gradually release the rule by lowering your hand. The rule will tilt. The angle between the rule and the horizontal is θ, as shown in Fig. 1.3. Fig.1.3 Measure and record θ. θ = …………………………….. [1]

4 Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use (ii) Estimate the percentage uncertainty in your value of θ. percentage uncertainty in θ = …………………………….. [1] (c) The quantities θ and n are related by the equation 2sin θ = C (0.5 n - n) where C is a constant. (i) Calculate C. C = …………………………….. [1] (ii) If you were to repeat this experiment with increasing values of n, describe the graph that you would plot and how you would determine C. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. ………………………………………………………………………………… [2]

5 [Turn over Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use (d) Theory suggests that MgC kL where M is the mass of the metre rule given on the card k is the spring constant of the spring system g = 9.81 m s-2 Use your value of C to determine a value for k. k = …………………………….. N m-1 [1] (e) The actual value of k is 25.0 N m-1. Comment on the accuracy of your result found in (d). …………………………..………………………………………………………………. …………………………………..………………………………………………………. …………………………………………..…………………………………………… [2] [Total: 9]

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7 [Turn over Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use 2 In this experiment, you will investigate a potential divider circuit. (a) (i) You have been provided with a wooden strip with some wire connected between two nails. Set up the circuit as shown in Fig. 2.1. Fig. 2.1 C and D are crocodile clips. Place the clips wire A so that the length x of the wire between C and D is equal to the length of wire between the two nails. Measure and record x. x = …………………………….. [1] (ii) Close the switch. Record the voltmeter reading V. V = ……………………………..

8 Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use (b) Vary x using the same wire A throughout. Repeat (a). Present your results clearly. [5] (c) It is suggested that the relationship between V and x is 11 x V kE E where k is a constant and E is the electromotive force (e.m.f.) of the cell. Plot a suitable graph to determine the value for k. k = …………………………….. [6]

9 [Turn over Anglo-Chinese Junior College 2021 J2 H2 9749 Paper 4 Preliminary Examination For Examiner’s Use (d) Without taking further readings, sketch a line on your graph grid to show the results you would expect if the experiment was repeated with a cell that has a larger e.m.f. Label this line W. [1] [Total: 13]

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