RVHS 2024 J2 H2 Physics Prelim P4

River Valley High School Page 1 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 . RIVER VALLEY HIGH SCHOOL JC2 PRELIMINARY EXAMINATIONS H2 PHYSICS 9749 PAPER 4 22 AUG 2024 2 HRS 30 MIN CANDIDATE NAME CENTRE NUMBER S INDEX NUMBER CLASS 2 3 J INSTRUCTIONS TO CANDIDATES DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO. Read these notes carefully. Write your name, class and index number above. Candidates answer 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. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. SHIFT LABORATORY FOR EXAMINERS’ USE 1 / 21 2 / 12 3 / 10 4 / 12 TOTAL / 55 This document consists of 18 printed pages.

River Valley High School Page 2 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 1 In this experiment, you will investigate the spring constant of a spring using the principle of moments. (a) (i) Measure and record the length l0 of the coiled section of the unstretched spring using the 30 cm ruler. l0 = ……………………….. [1] (ii) Hang a mass m of 300 g as shown in Fig. 1.1 below and measure the length l1 of the stretched spring. Calculate the extension, (l1 − l0). l1 − l0 = ……………………….. [1] (iii) The spring constant of the spring k is given by the expression 10 mgk = −ll where m is the mass used in (a)(ii) and g = 9.81 m s−2. Use your answer in (a)(ii) to calculate the spring constant of the spring k. k = ……………………….. [1] l0 l1 Fig. 1.1 rod of clamp retort stand boss

River Valley High School Page 3 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (b) Disconnect the previous setup and set up the apparatus as shown in Fig. 1.2. The distance x is the distance between the 300 g mass to the pivot, and the distance L is the distance between the pivot to the spring. Set x to be approximately 40 cm. Adjust the apparatus such that the metre rule is always parallel to the bench. (i) Displace the right end of the metre rule downwards over a short distance and release it. Allow the metre rule to oscillate about the pivot. Record x and determine the period T of these oscillations. x = ……………………….. T = ……………………….. [1] (ii) Estimate the percentage uncertainty in T. percentage uncertainty in T = ……………………….. [1] boss rod of clamp loop of string metre rule loop of string spring slotted masses L x Fig. 1.2 pivot

River Valley High School Page 4 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (iii) Repeat step (b)(i) for further values of x and T. The value of x should be more than 35 cm. Present your results clearly. [5] (iv) The quantities T and x are related by the expression 22T C Dx=+ where C and D are constants. Plot a suitable graph to determine C and D. C = ……………………….. D = ……………………….. [6]

River Valley High School Page 5 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024

River Valley High School Page 6 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (c) Explain why you should not use a value of x that is much smaller than 35 cm. ……………………………………………………………………………………............ ……………………………………………………………………………………... [1] (d) The constant D is directly proportional to the mass of the slotted masses m. This experiment is then repeated with a larger mass m. Sketch a line on your graph grid on page 5 to show the expected result. Label this line W. [1] (e) It is hypothesized that the spring constant k is inversely proportional to T. To vary k, attach an additional spring using the S -hook as shown in Fig. 1.3 below. A spring system with two springs connected in series has half of the spring constant compared to that of a single spring. By using your results in (b)(i) and taking one additional set of data, investigate whether this hypothesis is valid. Tabulate your results clearly. ……………………………………………………………………………………............ ……………………………………………………………………………………... [3] [Total: 21] Fig. 1.3 S-hook

River Valley High School Page 7 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 2 This investigation will consider current in an electrical circuit. (a) (i) Assemble the circuit as shown in Fig. 2.1. (ii) With the jockey pressed onto point A, adjust the rheostat until the ammeter reading is in the range 50 – 80 mA. Record the ammeter reading 0I . 0I = ……………………….. [1] (b) (i) Press the jockey onto the wire half -way between point A and the 50 cm mark. Record its distance L from the 50 cm mark and the ammeter reading I . L = ……………………….. I = ……………………….. [1] (ii) Estimate the percentage uncertainty in your value of I in (b)(i). percentage uncertainty = ……………………….. [1] 4.5 V 51 Ω resistance wire jockey metre rule L A A 1m wire (pre-connected) 1m wire Fig. 2.1 50 cm mark

River Valley High School Page 8 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (c) (i) Change L by placing jockey between point A and the 50 cm mark. Repeat (b)(i). Present your results clearly. [3]

River Valley High School Page 9 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (ii) Plot values of 1 I against L on the grid. The graph obtained should be a curve. [2] / A−1 0 10 20 30 40 50 L / cm

River Valley High School Page 10 of 18 H2 Physics 9749 JC2 Preliminary Examinations 2024 (d) The quantities L and I are related by the equation 21 baL= +I where a and b are constants. By selecting 2 points that lie on the graph plotted in (c)(ii), determine the values of a and b. Present your working clearly. Give appropriate units. a = ……………………….. b = ……………………….. [2] (e) (i) Theory suggests that the total resistance in the circuit is the largest when the jockey is pressed onto point A. Therefore, the current in the circuit will be a minimum. Using the value of current 0I in (a)(i), c alculate the reciprocal of the ammeter reading 0 1 I . 0 1 I = ………………………..