CJC.H2.PRELIM.2023.P4.QP

Catholic Junior College JC2 Preliminary Examinations Higher 2 CANDIDATE NAME CLASS 2T INDEX NUMBER PHYSICS 9749/04 Paper 4 Practical 21 Aug 2023 2 hour 30 minutes Candidates answer on the Question Paper READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB or 2B 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 appropriate units. Give details of the practical shift and laboratory where appropriate in the boxes provided. At the end of the assessment, fasten all your work securely together. The number of marks is given in brackets [ ] at end of each question or part question. This document consists of 15 printed pages and 1 blank pages. Shift Laboratory For Examiner’s Use 1 / 15 2 / 6 3 / 22 4 / 12 Total / 55

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3 [Turn Over 1. In this experiment, you will investigate the current in an electrical circuit. (a) You have been provided with two metre rules A and B, each with a resistance wire attached. Take measurements to determine the resistance per unit length of each of the wires. The resistance per unit length of the wire attached to rule A is RA. The resistance per unit length of the wire attached to rule B is RB. RA = …………………..….….……….. RB = …………………..….….……….. [2] (b) Set up the circuit as shown in Fig. 1.1. L should be approximately half the length of the rule and x should be greater than L. Close the switch. Measure and record L, x and the ammeter reading I. L = …………………..….….……….. x = …………………..….….……….. I = ……………………..….….……... [2] Fig. 1.1

4 (c) Vary x, obtaining a suitable range of values between 0 cm and 100 cm, and repeat (b), keeping L constant throughout. [3] (d) It is suggested that I and x are related by the expression =I + AB EE RL Rx where E is the electromotive force (e.m.f.) of the cell. Plot a suitable graph to determine the value of E. E = …………………..….…….. V [7] (e) Without taking further readings, sketch a line on your graph grid to show the results you would expect if the experiment was repeated with x measured on metre rule A and the same L in 1(b) measured on metre rule B. Label this line W. [1] [Total: 15]

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6 2. In this experiment, you will investigate an oscillating system. (a) Place the wooden strip on the pivot, as shown in Fig. 2.1. Adjust the position of the wooden strip on the pivot until it balances. The distance between the centre of the hole in the wooden strip and the pivot is l. Without marking on the wooden strip, measure and record l. l = …………………..….………. [1] (b) Set up the apparatus as shown in Fig. 2.2. The distance between the bottom of the split cork and the centre of the bob is H. Adjust the string in the split cork until H is approximately 40 cm. Displace the bob and the bottom of the wooden strip towards you through a short distance. Release the bob and the strip at the same time. The oscillations of the bob and the strip will be out of phase. Adjust H so that the oscillations of the bob and the strip remain in phase for several cycles after release. Measure and record H. H = …………………..….………. [1] Fig. 2.1 Fig. 2.2

7 [Turn Over (c) The quantities l and H are related by the equation ( )= −llbH where b is a constant. (i) Calculate b. b = …………………..….…….. m [2] (ii) If you were to repeat this experiment using a similar wooden strip with several holes at different positions along its length, describe the graph that you would plot to determine b. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… …………………………………………………………………………………………... ... [2] [Total: 6]

8 3. In this experiment, you will investigate the stiffness of some metal wires. A long-handled broom, as shown in Fig. 3.1, must be able to support the weight of the brush at the end without collapsing. Sometimes these brooms are used vertically to reach high places such as ceilings. In this experiment, you will model the broom handles using thin metal wires and investigate how the following properties of the wires affect their behaviour: • length • diameter • load • force constant. (a) You have been provided with three wires labelled P, Q and R. Measure and record the diameter d of wire P. d = …………………..….………. [1] (b) (i) Attach the sphere of modelling clay to one end of wire P and hold the wire vertically between your thumb and first finger. The length of wire between the centre of the sphere and the top of your thumb is h, as shown in Fig. 3.2. Fig. 3.1 Fig. 3.2

9 [Turn Over Increase h until the sphere moves down and touches the bench, as shown in Fig. 3.3. Determine and record h. h = …………………..….………. [1] (ii) Estimate the percentage uncertainty in your value of h. Percentage uncertainty in h = …………………..….………. [1] (iii) Suggest one significant source of uncertainty in this experiment. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………….... [1] (iv) Suggest an improvement that could be made to the experiment to reduce the uncertainty identified in (b)(iii). You may suggest the use of other apparatus or a different procedure. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………….... [1] Fig. 3.3

10 (c) Wire Q is made from the same material as wire P, but has a different diameter. Repeat (a) and (b)(i) for wire Q. d = …………………..….….……….. h = …………………..….….……….. [3] (d) It is suggested that 2=h cd where c is a constant. (i) Use your values from (a), (b)(i) and (c) to determine two values of c. Give your values for c to an appropriate number of significant figures. first value for c = …………………..….….………... second value for c = …………………..….….……….. [1] (ii) Justify the number of significant figures given to your values for c. …………………………………………………………………………………………………....... …………………………………………………………………………………………………....... …………………………………………………………………………………………………....... ………………………………………………………………………………………………..... [1] (iii) State whether the results of your experiment support the suggested relationship. Justify your conclusion by referring to your answer in (b)(ii). …………………………………………………………………………………………………....... …………………………………………………………………………………………………....... …………………………………………………………………………………………………....... ………………………………………………………………………………………………..... [1]