NYJC 2024 H2 PHY 9749 P4 Answers

NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CLASS TUTOR’S NAME CENTRE NUMBER S INDEX NUMBER PHYSICS 9749/04 Paper 4 Practical 19 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, class, tutor’s name, Centre number and index number 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 a HB 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 on 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. Shift Laboratory For Examiner’s Use 1 2 3 4 Total / 55 This document consists of 18 printed pages. H

2 NYJC 2024 9749/04/PRELIM 1 In this experiment, you will investigate the resistivity of a constantan wire. (a) (i) Connect the circuit as shown in Fig. 1.1 with the switch open. The wire on rule B should be connected by a crocodile clip at each end. L is the length of wire between the crocodile clips. (ii) With the switch open, record the voltmeter reading V. V = [2] (b) (i) Measure and record the length L. L = . (ii) Estimate the percentage uncertainty in your value of L. Fig. 1.1 1.583 V 1.4 V- 1.6V Correct range, units and dp 1.02m – 1.07m Correct range, units and dp [1]. Either one wrong is 0m 1.050 m L = 0.2 – 0.5 cm Percentage uncertainty = 𝛥𝐿 𝐿 × 100% = 0.3 105 × 100% = 0.3% 1 or 2 sf [1]. jockey Examiners’ comments: Students must measure the length carefully. The correct range needs to be given.

3 NYJC 2024 9749/04/PRELIM [Turn over percentage uncertainty = . [1] (c) (i) Close the switch. Place jockey on the wire on rule A at a distance x from the end of the rule, as shown in Fig. 1.2. The value of x should be about 40 cm. (ii) Measure and record the distance x and the ammeter reading I. x = . I = . (iii) Remove the