NJC 2026 H2 Physics Prelim P4

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 4 Practical Candidates answer on the Question Paper. No Additional Materials are required. 9478/04 2 Sep 2026 2 hours 30 Minutes READ THE INSTRUCTION FIRST Write your subject class, registration number and name 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 workings. 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 of 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 / 11 2 / 14 3 / 25 Total / 50 This document consists of 17 printed pages and 3 blank pages.

2 1 In this experiment, you will investigate an electrical circuit. (a) (i) Set up the circuit as shown in Fig. 1.1. Fig. 1.1 (ii) Connect the resistor P and one of the 5 k resistor (connected between W and Z) in series between X and Y to complete the circuit shown in Fig. 1.2. Fig. 1.2 Record the resistance R between W and Z. R = ............................................................ k switch A 1 k 1 k switch S1 switch S2 switch S1 switch S2 W Z switch A P + + C 4 V 4 V

[Turn over 3 (iii) Ensure that switch S1 is opened, close switch S2. Close switch A. Record the voltmeter reading V. V = .......................................................... [1] Open switch A. (b) Check that switch A and switch S1 are opened, while switch S2 is closed. Close switch A and open switch S2. Close switch S1 and start the stopwatch immediately. The voltmeter reading will change sign (positive to negative, or negative to positive) immediately and then gradually decrease in magnitude. Stop the stopwatch as soon as the voltmeter reading passes zero. Record the time t shown on the stopwatch. Open switch A and S1, close switch S2. t = .......................................................... [2] (c) By using different combinations of the 5 k resistors, repeat (b) until you have six sets of values of R and t. Record your results in a table. Include values from (a) and (b). When you have finished your measurements, open switch A. [3]

4 (d) It is suggested that the quantities t and R are related by the equation t = aR + b where a and b are constants. Use your answers from (c) and a spreadsheet to determine the value for b a. Give appropriate units. Sketch the graph in the space below. Write down the equation of the trendline. b a = ............................................................... [3] (e) Suggest the purpose of switch S1 and switch S2. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. …………………………………………………………………………………………………………… [2] [Total: 11]

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6 2 This investigation considers hot water that is poured into a container and allowed to cool in a room. (a) (i) Collect hot water from the hot water urn with the styrofoam cup. Ensure that the cup is covered with the lid. Carefully add approximately 100 ml of hot water to the smaller beaker from the styrofoam cup. Take measurements from 80 °C to 70 °C and use the grid provided to plot a curve to determine a value of dఏ dt when ߠ= 75 oC. dఏ dt = .......................................................... [3] ߠ / °C 0 50 100 150 200 250 t / s 70 80

[Turn over 7 (ii) Describe one problem in determining dఏ dt . ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………. [1] (b) A student wants to find the relation between the variation with time t and the temperature ߠ of the hot water as it cools. To determine how the water cools, the student uses a temperature sensor with data logger to measure how ߠ changes with t. The student’s temperature data is recorded in the digital file: datasetQ2b.xlsx. Upon further research, the student finds that ߠ is related to t by the equation: ߠ= m + neିkt where m, n and k are constant. Imagine you are the student. (i) Suggest, with a reason, what the constant m represents. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………. [2] (ii) Taking m to be 30 °C, plot a suitable graph using a spreadsheet to determine the value of n and k. Sketch the graph in the space below. Write down the equation of the trendline. n = ............................................................... k = ............................................................... [3]

8 (c) It is suggested that the constant k in the equation in (b) and the total surface area S of the water is related by k = ߙS + ߚ where ߙ and ߚ are constants. Plan an investigation to show if the relationship is valid. You are not required to do this experiment. You may assume that you are given a large number of cylindrical containers of the same material but different internal radius r. Include in your plan:  a diagram to show the arrangement of your apparatus  the procedure to be followed  how the mass of the water is kept constant  how you would use your results to show that the relationship is valid You may suggest the use of additional apparatus commonly found in a school physics laboratory. Diagram ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………….

[Turn over 9 ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. [5] [Total: 14]

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