NYJC 2024 H2 PHY 9749 P4

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 = ] (b) (i) Measure and record the length L. L = [1] (ii) Estimate the percentage uncertainty in your value of L. percentage uncertainty = [1] Fig. 1.1 jockey rule A rule B crocodile clip L crocodile clip V A

3 NYJC 2024 9749/04/PRELIM [Turn over (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 approximately 40 cm. (ii) Measure and record the distance x and the ammeter reading I. x = . I = . (iii) Remove the jockey from the wire on rule A and open the switch. (d) Repeat (c) for further values of x and the corresponding values of I. [3] Fig. 1.2 jockey x A

4 NYJC 2024 9749/04/PRELIM (e) Theory suggests that I and x are related by the expression P Qx=+I where P and Q are constants. Plot a suitable graph to determine the values of P and Q. P = . Q = . [6] (f) The experiment is repeated with a battery of larger value of e.m.f. Sketch a line on your graph grid used in (e) to show the expected result. Label this line W. [1] [Total: 12]

5 NYJC 2024 9749/04/PRELIM [Turn over

6 NYJC 2024 9749/04/PRELIM 2 In this experiment, you will investigate the oscillations of a torsional pendulum. Set up the apparatus as shown in Fig 2.1. Adjust the lengths of the strings such that the red markings on the strings lie just below the disc B, and secure the strings to disc B using the binder clips provided. Place four 50g masses on the centre of disc A in a vertical stack. Fig 2.1 (Front view) (a) Measure and record the distance L between the two discs. L = cm [1] (b) Displace disc A by a small angle about the centre of the disc. Release the disc so that it performs torsional oscillations in the horizontal plane about its centre. (See Fig. 2.2.) Fig. 2.2 (Top view) clips disc B retort stand L disc A stacked masses red marking oscillations of disc A small angular displacement masses

7 NYJC 2024 9749/04/PRELIM [Turn over Make measurements to determine the frequency f of the oscillations. f = Hz [3] (c) Make further measurements to determine the mass M required at the centre of disc A such that the frequency f of the oscillations is 1.50 Hz. Show your working clearly. M = g [3] (d) Explain why it is not feasible to determine the value of M for f = 5.00 Hz using the method in (c). [1] [Total: 8]

8 NYJC 2024 9749/04/PRELIM slot 100g slotted mass plastic straw D1 3 A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy. In this experiment, you will investigate the properties of a flywheel modelled by a slotted mass system. (a) (i) Measure and record the diameter D1 of the 100 g slotted mass. D1 = cm [1] (ii) Calculate C using 2 11C M D= where M1 = 0.100 kg. C = [1] (iii) Justify the number of significant figures that you have given for your value of C. [1] (iv) A plastic straw has been inserted into the slot of the slotted mass, as shown in Fig. 3.1. Fig. 3.1

9 NYJC 2024 9749/04/PRELIM [Turn over (v) Set up the apparatus as shown in Fig. 3.2. Loop one end of the string around one end of the straw and pass the rest of the string through the slot of the slotted mass and down to the floor, as shown in Fig. 3.2. Hook the mass hanger onto the other end of the string loop and then adjust the height of the flywheel until the mass hanger is just touching the floor and the rod is horiztonal. Fig. 3.2 retort stand boss wooden rod clamp gripping wooden rod bench top 100g slotted mass plastic straw string mass hanger floor string looped at one end of straw

10 NYJC 2024 9749/04/PRELIM (vi) Rotate the slotted mass 20 times so that the string is wound around the straw, as shown in Fig. 3.3. Fig. 3.3 Release the slotted mass and take measurements to determine the time t for the mass hanger to just touch the floor. t = [2] floor string wound around straw bench top