SAJC 2024 J2 H2 Physics Prelim P4

1 SAJC Prelims 20249749/04 Index Number Name 23S ST. ANDREW’S JUNIOR COLLEGE JC 2 2024 Preliminary Examination PHYSICS 9749/04 Paper 4 Practical 12 August 2024 2 hours 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions. READ THESE INSTRUCTIONS FIRST Write your name, index number and Civics Group in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Shift Laboratory Shift Laboratory 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.

2 SAJC Prelims 20249749/04 Give details of the 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. This document consists of 17 printed pages and 3 blank pages. BLANK PAGE For Examiner’s Use 1 /14 2 /8 3 /22 4 /11 Total /55

3 SAJC Prelims 20249749/04 1 In this experiment, you will determine the resistivity of a metal. (a) Set up the circuit as shown in Fig. 1.1, using the resistor of resistance R = 68 Ω. Place the jockey on the wire about half-way along the metre rule. The distance between the end of the wire and the jockey is y, as shown in Fig. 1.1. Close the switch. Adjust the position of the jockey until the ammeter reading I is as close as possible to 121 mA. Record R, I and y. R =……………………………………………

4 SAJC Prelims 20249749/04 I =…………………………………………… y =…………………………………………… [1] Open the switch. (b) Vary R and adjust y each time so that I is always as close as possible to 121 mA. Present your results clearly. [3] (c) It is suggested that R and y are related by the expression: where I is your value from (a) and Q and F are constants. Plot a suitable graph to determine values of Q and F.

5 SAJC Prelims 20249749/04 Q =…………………………………………… F =…………………………………………… [8]

6 SAJC Prelims 20249749/04 (d) Theory suggests that: where d is the diameter of the wire and  is the resistivity of the metal. Determine a value for .  =…………………………………………… Ωm [2] [Total: 14]

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8 SAJC Prelims 20249749/04 2 In this experiment, you will investigate an oscillating system. Two bobs A and B are supported by strings. The string supporting A has a mark at its midpoint. Set up the apparatus as shown in Fig. 2.1. (a) (i) The long wooden rod should pass between the stand and the strings. The angle between the long wooden rod and the string supporting A is θ.

9 SAJC Prelims 20249749/04 Adjust the position of the long wooden rod so that  is approximately 60° and the rod is behind the mark on the string supporting A. The rod should be just touching both strings, with the strings hanging vertically. Measure and record .  =……………………………………………⁰ [1] (ii) Pull A and B a short distance away from the long wooden rod. Keep the same separation between A and B. Release A and B at the same time. B first oscillates in phase with A, then out of phase, and then back in phase again. This takes n oscillations of B. Determine n. n =…………………………………………… [2] (b) It is suggested that: n = k tan where k is a constant. Calculate k. k =…………………………………………… [2] (c) Determine n and k for two more values of . Tabulate your results.

10 SAJC Prelims 20249749/04 [2] (d) Explain why you would not select a value of  = 90⁰ in (c). …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… ………………………………………………………………………………………………….[1] [Total: 8] BLANK PAGE