SNGS 2025 PHY PRELIM P3 MS

1 SNGS Sec 4 Physics Prelim Practical 2025 Name ___________________________ ( ) Class _______ PRELIMINARY EXAMINATION GENERAL CERTIFICATE OF EDUCATION ORDINARY LEVEL PHYSICS 6091/03 Paper 3 Practical Test 15 August 2025 1 hour 50 minutes Candidates answer on the Question Paper. READ THESE INSTRUCTIONS Write your name and index number on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue, correction fluid, correction tape or highlighters. 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 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 [ ] at the end of each question or part question. Shift Laboratory For Examiner’s Use 1 /10 2 /10 3 /20 Total /40 This document consists of 13 printed pages. [Turn Over [Grab your reader’s attention with a great quote from the document or use this space to emphasize a key point. To place this text box anywhere on the page, just drag it.]

2 SNGS Sec 4 Physics Prelim Practical 2025 Section A 1 In this experiment you will determine the length of a wire used in the experiment. You are provided with: • a power supply • a switch • a variable resistor • a 3V voltmeter • a 1A ammeter • a half-metre rule • a nichrome resistance wire • connecting leads. The nichrome resistance wire is partially hidden inside an envelope and the remainder is held onto a piece of cardboard by pieces of clear tape. You must not remove the wire from the cardboard, or interfere with the envelope in any way. You must not write on, or mark, the cardboard in any way. Set up the circuit as shown in Fig. 1.1. Fig. 1.1 Place your ruler along the resistance wire on the cardboard so that the zero mark on the ruler is at point C, where the wire leaves the crocodile clip. You are going to place the moving contact on the resistance wire at different distances, x, from point C and measure the current through the circuit. x C

3 SNGS Sec 4 Physics Prelim Practical 2025 (a) Place the moving contact on the resistance wire at a point approximately 40 cm from C. Measure and record the value of x. Length reported to 1 dp in cm with unit clearly stated, range between 38 to 42 cm. x = ………………………… [1] (b) (i) Close the switch and adjust the variable resistor until the voltmeter shows the maximum possible value. Measure and record the voltage V and the current in the circuit, I. V precision is 0.05 V I precision is 0.01 A V value should exceed 2.00 V (push variable resistor to min) V = ……………………… I = ……………………… [2] (ii) Hence calculate the resistance of the nichrome resistance wire, R. R =V/I = 2.40 / 0.34 = 7.1 Ω R = ……………………… [2] (c) Given that the resistivity of nichrome is 1 .00 × 10-6 Ω m, and the cross-sectional area of the wire is 6.2 × 10-8 m2, calculate the length of the resistance wire across the voltmeter and hence estimate the length of resistance wire hidden in the envelope. 𝑙 = 𝑅×𝐴 𝜌 = 7.1 ×6.2×10−8 1.00 × 10−6 = 0.44 𝑚 [B1] Length of wire from crocodile clip to end of cardboard = 3.5 cm Length of wire extending out from envelope on the other side = 1.0cm (if not explicitly written BOD) Length of wire in envelope = 44 – 3.5 – 1.0 [M1] = 39.5 = 40 cm [A1, correct precision and unit] *Note common error is student subtracting x from l, rather than the remnant from length of cardboard minus x.Such students will only get 1 mark from finding l. length of resistance wire across voltmeter = ……………………… length of resistance wire in envelope = ……………………… [3] 40.0 cm 0.34 A 2.40 V 7.1 Ω 40 cm 37 cm

4 SNGS Sec 4 Physics Prelim Practical 2025 (d) Suggest how the cross-sectional area of the resistance wire may be determined accurately and reliably. ..................................................................................................................... ..................................................................................................................... ..................................................................................................................... ................................................................................................................ [2] . [Total: 10] Measure the diameter of the resistance wire with a digital micrometer screw gauge [1]. Calculate the area using (d2/4). Make repeated measurement of diameter at different points (BOD) along the length of wire and take average [1] For loops method 20 loops [1] with ruler, and calculate [1] can use micrometer screw gauge (non-digital)

5 SNGS Sec 4 Physics Prelim Practical 2025 2 In this experiment you will determine the mass of a half-metre rule. You are provided with: • a half-metre rule with holes near both ends • a length of string attached to the half-metre rule at the 49.0 cm mark • a pivot in the form of a pin mounted on cork on a retort stand • a 50 g mass hanger labelled P and five 20 g masses • a pulley • a retort stand with boss and clamp • a metre rule • a protractor • two bricks. The supervisor has set up the apparatus as shown in Fig. 2.1. Fig. 2.1 Pass the string through the pulley and hang the mass hanger from the loop at the free end of the string . Set up the apparatus as shown in Fig. 2.2 , with the pulley held up by the second retort stand (not shown in diagram). The mass hanger must be above the benchtop when the string is horizontal. Fig. 2.2 brick pulley  l B A

6 SNGS Sec 4 Physics Prelim Practical 2025 (a) Explain how you ensured that AB was horizontal. ……………………………………………………………………………………. ……………………………………………………………………………………. ………………………………………………………………………………… [1] (b) (i) Record the mass m of the load that is suspended from the loop. m = …………………………. (ii) Measure and record the distance l between the centre of the holes on the half-metre rule. l = ………………………… [1] (iii) Measure and record the angle  that the half-meter rule makes with the horizontal, and calculate the value of tan . Angle given to nearest whole number, tan  reported to 2sf  = …………………………. tan  = …………………………. [2] (c) Add a 20 g mass to the mass hanger. Record the new value of m. Do not accept 2 d.p. as mass balance is not an apparatus for this experiment and hence they should not have measured its mass. m = …………………………. [1] (d) Adjust your setup such that AB is horizontal again. Measure and record the new value of , and calculate the new value of tan .  = …………………………. tan  = …………………………. [1] Measure the height of the string at 2 points along AB using a metre rule. If the height is the same at these two points, the string is horizontal. [ Also accept horizontal reference w