2024 VJC H2 Prelim Practical P4 with Answers for students

VICTORIA JUNIOR COLLEGE 2024 JC2 PRELIMINARY EXAMINATION Higher 2 Name : _____Answers________________ CT group : ________________ PHYSICS Paper 4 Practical Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions 9749/04 29 August 2024 2 hours 30 minutes READ THESE INSTRUCTIONS FIRST Write your name and Civics Group 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. DO NOT WRITE ON ANY BARCODES. 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. 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 Examiner’s Use 1 2 3 4 Total This document consists of 18 printed pages.

2 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 = ……68 Ω………………. I = ……121.0 mA………….. y = ……60.0 cm…………….. [1] Open the switch. Fig. 1.1 2024 Prelim Physics H2 P4 Practical Suggested Answers

3 (b) Vary R and adjust y each time so that I is always as close as possible to 121 mA. Present your results clearly. R/Ω y/cm R/y / Ω cm -1 56 61.1 0.92 68 60.0 1.1 82 56.3 1.5 100 54.6 1.83 120 53.3 2.25 150 52.2 2.87 [3] (c) It is suggested that R and y are related by the expression: R Q R Qy F I where I is your value from (a) and Q and F are constants. Plot a suitable graph to determine values of Q and F. Plot R/y vs R, gradient = QI/F, and y-intercept = -Q 12 70 1 00 1 70 0 0213140 0 60 0 80 0 ( . . ) . . cm( . . ) .grad    Subst (140.0, 2.70) into y = mx + c 2.70 = 0.0213(140.0) + c Hence y-int, c = - 0.282 Ω cm-1 Hence Q = 0.282 Ω cm-1 0 0213 0 282 0 1210 0 0213 0 282 0 1210 1 600 0213 . . . . . . . V (or A ). Q F F F       I Q = ……0.282 Ω cm-1……….. F = ……1.60 V……………….. [8] When R is 2 sf, y is 3sf Then R/y is only 2 sf. When R is 3 sf, y is 3sf, then R/y is 3 sf.

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