TMJC Review 2024 J2 H2 Prelim P4

This document consists of 15 printed pages and 3 blank page. TAMPINES MERIDIAN JUNIOR COLLEGE JC2 Practical Preliminary Examination Higher 2 H2 Physics 9749/04 Paper 4 Practical 22 Aug 2024 2 hours 30 minutes Candidates answer on the Question Paper. No Additional Materials are required. Class Index No Candidate Name: READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page, page 9 and page 15. 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 the questions. You are allowed 1 hour to answer Questions 1 and 2; and you are allowed another 1 hour to answer Question 3. Question 4 is a question on the planning of an investigation and does not require apparatus. Write your answers in the space provided in 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. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 /8 2 /14 3 /21 4 /12 Total /55 Shift Laboratory

2 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Physics 1 In this experiment, you will investigate how the frictional force between a plastic pipe and string varies with the length of string in contact with the pipe. (a) Use the vernier calliper to measure and record the outer diameter d of the plastic pipe. Comments Common mistakes include not writing zero error and no repeat for d. d = ………………………………cm [1] (b) Estimate the percentage uncertainty in your value of d. percentage uncertainty in d = ……………………………… [1] (c) Assemble the apparatus as shown in Fig. 1.1. Tie the 20 g mass to the one end of the string and the 50 g mass hanger to the other end. Fig. 1.1 Wrap the string 1.5 times around the pipe. The turns of string must not touch each other. 20 g mass string plastic pipe [1] Correct absolute uncertainty of 0.02 cm 0.05 cmd  (1 s.f) % uncertainty calculated correctly with same precision (of numerator and denominator) and correct s.f (2.s.f) [1] Check zero error; 2 d.p. and repeated. Accept 2.65 cm ≤ d ≤ 2.75 cm. No zero error. d = (2.70 + 2.70)/2 = 2.70 cm % uncertainty in d = (0.02 / 2.70) × 100% = 0.74%

3 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Physics (d) Use your values from (a) to calculate the length l of string in contact with the pipe. Comments Common mistakes include wrong calculation/formula for l l = ……………………………… [1] (e) Gently add masses to the hanger until the hanger just starts to move down to the bench. Record this mass m (including the mass of the hanger). m = ……………………………… [1] Comments Common mistakes include no repeat for m. (f) Remove the masses from the hanger and then wrap the string one more time around the pipe, so that it is now wrapped around the pipe 2.5 times. Repeat steps (d) and (e). l = ……………………………… m = ……………………………… [2] (g) It is suggested that m and l are related by the equation m2=k l3 where k is a constant. (i) Use your values from (d), (e), and (f) to determine two values of k. first value of k = ……………………………… second value of k = ……………………………… [1] l =  d × 1.5 = 12.7 cm [1] Correct calculation and s.f. (3 s.f.) m1 = 200 g m2 = 200 g mave = 200 g l =  d × 2.5 = 21.2 cm m1 = 500 g m2 = 500 g mave = 500 g [1] Correct calculation and s.f. of l (3 s.f.) [1] Repeat reading, correct unit and d.p. of m (nearest g or kg), value in (f) > value in (e) k1 = (200)2 / 12.73 = 19.5 g2 cm-3 k2 = (500)2 / 21.23 = 26.2 g2 cm-3 [1] 2 values of k correctly calculated, correct unit and s.f. (3 s.f.) value in (f) > value in (e) [1] Correct unit and d.p. Repeated values

4 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Physics (ii) State whether or not the results of your experiment support the suggested relationship. Justify your conclusion by referring to your value in (b). …………………………………………………………….………………………………….. …………………………………………………………….…………………………… [1] [Total: 8] BLANK PAGE d.p. (nearest g or kg) % difference of k = (26.2 - 19.5) / 19.5 = 34% The percentage difference of the two k values is 34% which is larger than the percentage uncertainty of 0.74% determined in (b). Thus, we can conclude that the results the experiment do not support the suggested relationship, within limits of the experiment. [1] Compare k percentage difference with percentage uncertainty in (b) and make conclusion.

5 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Physics 2 In this experiment, you will investigate the relationship between the potential difference across a resistance wire and a filament bulb. Fig. 2.1 Fig. 2.1 shows a circuit consist ing of a resistance wire on a metre rule and a light bulb arranged in series. (a) (i) Connect the circuit as shown in Fig. 2.1. (ii) Position the clip J at a position half way along the wire. Close the switch S. Record the length z, voltmeter reading V1 across the resistance wire and the voltmeter reading V2 across the light bulb. z = ……………………………… V1 = ……………………………… V2 = ……………………………… [1] 1.5 V d.c. supply S V2 resistance wire on a metre rule z V1 J z = 40.0 cm V1 = 0.698 V V2 = 0.458 V [1] z, V1, V2: Correct d.p. and units. Accept 38.0 cm ≤ z ≤ 42.0 cm.

6 Tampines Meridian Junior College 2024 JC2 Preliminary Examination H2 Physics (b) Repeat steps (a)(ii) to obtain further sets of values of z, V1 and V2. [5] (c) It is suggested that z, V1 and V2 are related by the equation 2 1 V G HVz=+ where G and H are constants. Plot a suitable graph to obtain values for G and H. G = ……………………………… H = ……………………………… [6] z/cm V1/V V2/V 2 1 V V 1 z /cm-1 20.0 0.389 0.740 1.90 0.0500 30.0 0.553 0.576 1.04 0.0333 40.0 0.698 0.458 0.656 0.0250 60.0 0.857 0.388 0.453 0.0167 70.0 0.920 0.210 0.228 0.0143 80.0 0.990 0.164 0.166 0.0125 [2] Able to setup experiment to obtain 6 readings with correct trend Award one mark if student only obtained 5 sets of reading Deduct 1 mark if range is not at least 75% (i.e. 60 cm). Deduct 1 mark if the max value of z is more than 80 cm. Deduct 1 mark if the first reading of z, V1 and V2 values from (a)(ii) is not in table. Deduct 1 mark if min z value given is 0 cm (implying not having wire in circuit). Deduct 2 marks if trend is negative (referring to wrong raw data obtained) Deduct 2 marks if V1 or V2 remains unchanged. Ignore if V1 or V2 is negative but must be negative throughout the column (if not, deduct 1 mark) [1] Correct quantity and units in headers (according to symbols given in qn) [1] Correct d.p for raw data [1] Correct calculation and s.f for derived data Plot a graph of 1 2 V V vs 1 z . If the above relationship is valid, a straight line with G as gradient and H as vertical intercept will be obtained. Gradient = y1-y2/x1-x2 = …. = 45.1; G = 45.1 cm vertical-intercept = y1-mx1 = …. = -0.400; H = -0.400 [1] Correct statement of linearisation (underlined words above). [1] Gradient triangle covers more than ½ of BFL.