NYJC 2023 H2 Physics 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 21 August 2023 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 / 15 2 / 6 3 / 22 4 / 12 Total / 55 This document consists of 19 printed pages. H

2 NYJC 2023 9749/04/PRELIM/23 1 In this experiment, you will investigate an electrical circuit. (a) Set up the circuit shown in Fig. 1.1, using a 15  resistor as P and a 22  resistor as Q. Fig. 1.1 K and L are crocodile clips. Place L approximately half-way along the wire. The distance between K and L is y as shown in Fig. 1.1. Record P, Q and y. P = Q = y = Close the switch. Record the ammeter reading I. I = [1] Open the switch. P Q

3 NYJC 2023 9749/04/PRELIM/23 [Turn over (b) Change one or both of the resistors in P and Q. Record the new values of P and Q. P = Q = Close the switch. Change the position of L on the wire so that the ammeter reading is as close as possible to the value for I in (a). Record y. y = [1] Open the switch.

4 NYJC 2023 9749/04/PRELIM/23 (c) Repeat (b) until you have six sets of readings of P, Q and y, using different combinations of the resistors provided as P and Q. Present your results clearly. [5] (d) It is suggested that the quantities y, P and Q are related by the expression MPQyN PQ=− ++ where M and N are constants. Plot a suitable graph to determine M and N. M = N = [6]

5 NYJC 2023 9749/04/PRELIM/23 [Turn over

6 NYJC 2023 9749/04/PRELIM/23 (e) Theory suggests that NE MI= where E is the electromotive force (e.m.f.) of the cell. Calculate E. Give an appropriate unit. E = [1] (f) M is inversely proportional to r, the resistance per unit length of the wire taped to the meter rule, while N is the ratio of the total resistance in the circuit to r. On the graph on page 5, draw the line that would show the result obtained if the wire taped to the meter rule is changed to one made of the same material, but having a larger diameter. [1] [Total: 15] I

7 NYJC 2023 9749/04/PRELIM/23 [Turn over 2 In this experiment, you will investigate an oscillating system. (a) Place the wooden strip on the pivot, as shown in Fig. 2.1. Fig. 2.1 Adjust the position of the wooden strip on the pivot until it balances. The distance between the centre of the hole in the wooden strip and the pivot is L. Without marking the wooden strip, measure and record L. L = [1] (b) Set up the apparatus as shown in Fig. 2.2. Fig. 2.2 The distance between the bottom of the split cork and the centre of the bob is H. Adjust the string in the split cork until H is approximately 40 cm. Displace the bob and the bottom of the wooden strip towards you through a short distance. Release the bob and the strip at the same time. The oscillations of the bob and the strip will be out of phase. Adjust H so that the oscillations of the bob and the strip remain in phase for several cycles after release. Measure and record H. H = [1] L

8 NYJC 2023 9749/04/PRELIM/23 (c) The quantities L and H are related by the equation ()b L H L=− where b is a constant. (i) Calculate b. b = m [2] (ii) If you were to repeat this experiment using a similar wooden strip with several holes at different positions along its length, describe the graph that you would plot to determine b. [2] [Total: 6]

9 NYJC 2023 9749/04/PRELIM/23 [Turn over 3 A simplified mechanism of a fuel gauge in a car is shown in Fig. 3.1. A rod attached to a float rotates about a pivot as the float moves up or down. This causes the reading on the fuel gauge to change. Fig. 3.1 In this experiment, you will investigate a model of this mechanism. You have been provided with a metre rule which models as the rod, and a tube which models as the float. (a) (i) The distance between the centre of the hole in the metre rule and the 50 cm mark on the metre rule is L, as shown in Fig. 3.2. Fig. 3.2 Determine L in metres. L = m The outer diameter of the tube is d, as shown in Fig. 3.3. Fig. 3.3 Measure and record d in metres. d = m [1]

10 NYJC 2023 9749/04/PRELIM/23 (ii) Calculate the cross-sectional area A of the tube where 2 4 dA = . A = m2 [1] (b) (i) Add sand to the tube as shown in Fig. 3.4. Fig. 3.4 The height of sand in the tube is x. Adjust the amount of sand in the tube until x is approximately 12 cm. Measure and record x in metres. x = m (ii) Push the stopper securely into the tube.