Temasek 2024 Prelim 4E Phy P3 ANS

No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. Name: _________________________ Index Number: Class: _______ TEMASEK SECONDARY SCHOOL O Level Preliminary Examination 2024 Secondary 4 Express PHYSICS 6091 / 03 Paper 3 Practical 1 hour 50 minutes Additional Material: NIL READ THESE INSTRUCTIONS FIRST Do not open the booklet until you are told to do so. You are required to submit this booklet at the end of the paper. Write your name, index number and class on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Answer all questions. All of your answers should be written in this Question Paper: scrap paper must not be used. Graph paper is provided in this Question Paper. Additional sheets of graph paper should be used only if it is necessary to do so. You will be allowed to work with the apparatus for a maximum of 55 minutes for each section. You are expected to record all your observations as soon as they are made. An account of the method of carrying out the experiments is not required. The use of an approved scientific calculator is expected, where appropriate. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] as the end of each question or part question. For Official Use 1 2 3 Total Shift Laboratory This document consists of XX printed pages. 40

2 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. Section A 1 In this experiment, you will investigate an electrical circuit containing a light - emitting diode (LED). You are provided with • a power supply (consists of two 1.5 V batteries with battery holders), • a switch, • a light-emitting diode (LED), • 1500 Ω and 6200 Ω resistors, • a voltmeter, • 6 connecting leads, • a digital micrometer. (a) The LED has two legs, one labelled positive, and the other labelled negative. Measure and record the diameter of any one leg. diameter = …………………………. [1] Record to 2 dp in mm Acceptable range Assemble the circuit shown in Fig. 1.1, where R = 1500 Ω. Fig. 1.1 (b) (i) Connect the voltmeter across junctions Y and Z to measure the potential difference (p.d.) VR across R. Close the switch and record VR. VR = …………………………. [1] 1.20 V (2 dp with correct unit) (ii) Open the switch and disconnect the voltmeter. R

3 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. Calculate the current 𝐼 in the circuit using the relationship 𝐼 = 𝑉𝑅 𝑅 where R is the resistance of the resistor that is in the circuit. 𝐼 = …………………………. [1] I = 1.20 / 1500 = 8.00 × 10-4 A (correct sf, unit) (iii) Connect the voltmeter across junctions X and Y to measure the p.d. V across the LED. Close the switch and record V. V = …………………………. [1] 1.80 V (2 dp with correct unit) (iv) Calculate the power P dissipated in the LED using the relationship 𝑃 = 𝐼 𝑉 P = …………………………. [1] P = (8.00 × 10-4)(1.80) = 1.44 × 10-3 W (correct sf, unit) (c) Disconnect the 1500 Ω resistor and replace it with the 6200 Ω resistor. (i) Repeat (b) and record the new values of VR and V. VR = …………………………. V = …………………………. [1] 1.30 V; 1.00 V (2 dp with correct unit) (ii) Calculate new values of 𝐼 and P. 𝐼 = …………………….……. P = …………………………. [1] I = 1.30 / 6200 = 2.10 × 10-4 A P = 2.10 × 10-4 W Both correct to get 1 mark (correct sf, unit) (iii) R is increased from 1500 Ω to 6200 Ω.

4 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. [Total: 10] Compare the increase in R with the change in 𝐼 and with the change in P. .……………………………………………………………………..……… .…………………………………………………………………………. [1] When R increases, I decreases and P decreases. [1] (d) Describe how modifications can be made to the circuit in Fig. 1.1 to measure 𝐼 directly and for a range of values of R. ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………………….... [2] Connect an ammeter in series. [1] Replace fixed resistor with a variable resistor / rheostat. [1] 2 In this experiment, you will invest igate how the speed of a water wave changes as the depth of the water is altered. You are provided with • a tray, • a beaker • a marked stick, • a stopwatch, • a half-metre rule. Set up the apparatus shown in Fig. 2.1. With the tray flat on the bench, carefully pour water into it so that the depth, d, is 10 mm. Use the marked stick provided to help you measure this depth. L tray water d

5 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. Fig. 2.1 (a) Measure and record the length L of the tray. L = ………………………….. [1] Acceptable range with unit [1] Raise one side of the tray, A, by about 15 to 20 mm, as shown in Fig. 2.2 and then let it drop back to the bench. Fig. 2.2 You should see a wave move forward and backward across the surface of the water several times, as shown in Fig. 2.3. Fig. 2.3 One cycle consists of a wave crest traveling from side A of the tray to side B and back again to side A. (b) Determine an accurate time t taken for a wave crest to complete 3 cycles. t = ………………………….. [2] evidence of average taken [1] accuracy of value and to correct dp [1] e.g. t = (3.9 + 4.1 + 3.9) / 3 = 4.0 s A B 15 to 20 mm wave crest moves from side A to side B wave crest moves from side B to side A wave crests one cycle A B

6 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. (c) Calculate the average speed of the wave, c, using the formula 𝑐 = 6𝐿 𝑡 c = ………………………….. [1] c = 6(165 mm) / 4.0 s = 250 mm/s [1]

7 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. (d) Plan It is suggested that the average speed c and depth d are related by the expression: 𝑐 = 𝐴√𝑑 + 𝐵 where A and B are constants. Using the same apparatus given in this experiment, plan an experiment to investigate this relationship. In your plan, you should: • state one key variable to control. • explain briefly how to do the experiment. • describe how to vary d. • draw a table, with column headings, to show how to display the range of readings. • write a statement of the graph to plot to test this relationship. • explain how to determine A and B if the relationship is valid. ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..………………

8 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. [Total: 10] ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… ……………………………………………………………………..……………… …………………………