PLMGS 2026 Physics P3 QP + MS

[Turn over CENTRE NUMBER S INDEX NUMBER PHYSICS (G3) 6091/03 Paper 3 Practical 24 August 2026 1 hour 50 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class, class index number, centre number and O level index number on the cover page. Give details of the practical shift and laboratory where appropriate, in the boxes provided. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. At the end of the examination, fasten all your work securely together, if applicable. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 11 printed pages. CANDIDATE NAME ( ) CLASS TG Shift Laboratory For Examiner’s Use 1 /10 2 /10 3 /20 Total /40 Paya Lebar Methodist Girls’ School (Secondary) Preliminary Examination 2026 Secondary 4 Express Secondary 4 Express / G3

2 1 In this experiment, you will investigate an electrical circuit. You are provided with • two 1.5 V cells with holders, • an ammeter, a voltmeter, a switch, • a resistance wire taped to a metre rule, • an unknown resistor Y, • 7 short connecting wires and 1 long wire labelled G, • a digital micrometer screw gauge. (a) (i) Measure and record an accurate value of diameter d of the resistance wire taped to the metre rule. d = ………………………… [2] (ii) Describe one precaution that you have taken when determining the diameter d of the resistance wire. ………………………………………………………………………………………….. ………………………………………………………………………………………….. [1] (b) Set up the circuit as shown in Fig. 1.1 with the switch open. Fig. 1.1 There are two crocodile clips F and G that can be connected to the resistance wire. F will remain in the same position throughout the experiment. G can be moved. (c) (i) Attach G to the wire at a distance x about 50 cm from the end of the rule, as shown in Fig. 1.1. Record the distance x. x = ___________________ [1] resistance wire metre rule Y H

3 (ii) Close the switch. Record the ammeter reading I1 and the voltmeter reading V1. I1 = ………………………… V1 = ………………………… [2] Remove G from the wire and open the switch. (iii) Suggest one improvement that could be made to the measurement of x. …………………………………………………………………………………………….. …………………………………………………………………………………………….. [1] (d) (i) Use your measurements in (c)(ii) to determine R1, the value of resistance of Y. R1 = …………………………... [1] (ii) Attach G to point H of the wire shown in Fig. 1.1. (iii) Close the switch. Record the ammeter reading I2 and the voltmeter reading V2. I2 = …………………………... V2 = …………………………... [1] (iv) Determine R2, the value of resistance of Y. R2 = …………………………... (e) Your teacher claims R1 and R2 should be equal. Using appropriate calculations, prove whether your teacher is correct or wrong. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… …………………………………………………………………………………………………… [1] [Total: 10] [Turn over

4 2 In this experiment, you will investigate the rate of energy transfer by light. You are provided with • retort stand A, 2 bosses, 2 clamps, • a lamp secured to the retort stand A, connected to an AC power supply, • retort stand B, 1 boss, 1 clamp, • a thin converging lens, • a portable screen made from a piece of white card pasted on a wooden block, • a stopwatch, a thermometer, • a half-meter rule, a 15-cm ruler. Set up the apparatus as shown in Fig. 2.1. Fig. 2.1 Do not adjust the height of the lamp. Switch on the power supply. (a) Adjust the height of the clamp holding the lens until the smallest bright spot is formed on the portable screen. The bright spot is the sharply focused image of the filament of the lamp. Measure the distance v from the centre of lens to the portable screen. v = …………….. (b) Measure and record the room temperature TR. TR = ………………. (c) Power rating of the lamp is 60 W. Calculate the amount of energy E provided to the lamp in 3.0 minutes. E = …………………… [1] retort stand A filament lamp covered with a cylindrical shade lens v portable screen (white card on wooden block) SAFETY The lamp is HOT! Do not touch the lamp.

5 Position the thermometer clamped to retort stand B as shown in Fig. 2.2 such that the bulb rests on the portable screen. Fig. 2.2 Position the thermometer such that the light rays from the lamp converge at the center of the bulb of the thermometer. Start the stopwatch. (d) After 3.0 minutes, measure and record the temperature on the thermometer TH. TH = ………………….. [1] (e) The thermometer uses alcohol to measure temperature. Suggest a reason for the difference between TH and TR. …………………………………………………………………………………………………... …………………………………………………………………………………………………... ………………………………………………………………………………………………….. [1] (f) Describe a modification to the thermometer so that the time taken for the final temperature reading to be reached is reduced. …………………………………………………………………………………………………... …………………………………………………………………………………………………... …………………………………………………………………………………………………... [1] filament lamp lens lamp lens filament thermometer retort stand B [Turn over

6 (g) A student suggests that the TH - TR = av2 + b, where a and b are constants and v is the distance between the optical centre of the lens and the bulb of the thermometer. Using the same apparatus, plan an experiment to investigate this relationship. In your plan, you should: • describe briefly how to set up the experiment • draw a table, with column headings, with correct units • explain how to determine a and b if the student’s claim is correct. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………………….

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