ACS Exp Prelim 2024 P3 final

This document consists of 11 printed pages PRELIMINARY EXAMINATION 2024 YEAR 4 EXPRESS PHYSICS 6091 / 03 Tuesday 30 July 2024 1 hour 50 minutes READ THESE INSTRUCTIONS FIRST Write your index number and name on all the work you hand in. Write in dark blue or black pen. You may use an 2B pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. 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 [ ] at the end of each question or part question. Index Number Name For Examiner’s use 1 2 3 Total

Y4Exp Physics Preliminary Examination 2024 Page 2 of 11 Section A 1 In this experiment, you will deduce the path taken by a light ray undergoing total internal reflection in a glass block. You are provided with: • A4 Plain Paper • Cork mat • Five optical pins • Rectangular glass block • Protractor • 30.0 cm ruler • Set square Fig. 1.1 (not to scale) (a) Place the largest surface of the block in the middle of the sheet of plain paper. Draw around the block to mark its position. Remove the glass block and label the corners ABCD as shown in Fig. 1.1. Draw a normal at point M, 1.0 cm from the corner point B of the block, as shown in Fig. 1.1. Use the protractor to construct an incident ray at an angle of incidence i of 30o. Replace the block and place the plain paper on the cork mat. Place the two object pins P1 and P2 along the incident ray. Position your eyes to look through the side CD of the glass block. You should observe 2 reflected images of P1 and P2 appear at side BD when looking through the side CD. 1.0 cm

Y4Exp Physics Preliminary Examination 2024 Page 3 of 11 Place two further pins P3 and P4 in line with the reflected images of P1 and P2 so that, when viewed through the block, the four pins appear to be one behind the other. Remove the block and draw a line joining P4 and P3 to the edge of the block and mark the point of intersection as point N. This line is the emergent ray. Measure and record the distances BD and ND from your trace using the ruler. BD = ......................................................... [1] ND = ......................................................... [1] (b) (i) Calculate the value of x, using the equation 𝒙 = 𝑩𝑫 𝑵𝑫+𝟏.𝟎 × 1.0 𝑐𝑚 , where BD and ND are expressed in centimetres. x = ......................................................... [1] (ii) At a distance of x below corner B of the block, mark out the point O on side BD, as shown in Fig. 1.1. Draw straight lines from M to O, and O to N to represent the path taken by the incident ray after entering the block. Measure the angle of refraction r inside the block. r = ......................................................... [1] (c) State 2 precautions you took to improve the accuracy of the experiment. 1 ……………………………………………………………………………………… ……………………………………………………………………………………… 2 ……………………………………………………………………………………… ……………………………………………………………………………………… [2] (d) Comment on the relationship between the angle of incidence, i, and the angle of emergence, e, based on your experiment. ……………………………………………………………………………………….. [1] (e) Submit your trace together with this answer sheet at the end. [4] [Total: 10]

Y4Exp Physics Preliminary Examination 2024 Page 4 of 11 2 In this experiment, you will investigate the current in a circuit where a fixed resistor and a variable resistor are arranged in parallel. You are provided with: • a 3.0 V battery holder with batteries • a switch • an ammeter • a voltmeter • a length of resistance wire mounted on a metre rule • six connecting leads • a resistor labelled R • a jockey Fig. 2.1 Set up the apparatus as shown in Fig. 2.1. The jockey can be connected at different points along the length of the resistance wire. Connect the jockey to the wire at the 50.0 cm mark of the ruler. Close the switch. (a) With the jockey still connected in this position, (i) Record the length, L, from the 0.0 cm mark of the metre rule to the position of the jockey on the wire, in metres. L = ..................................................... m [1] (ii) Record the reading of current on the ammeter, I. I = ......................................................... [1] (b) Open the switch. Disconnect the jockey from the resistance wire. Connect the voltmeter across the two ends of the battery. Record the reading of electromotive force (e.m.f.) on the voltmeter, V. V = ......................................................... [1]

Y4Exp Physics Preliminary Examination 2024 Page 5 of 11 (c) Calculate the value of 1/L. 1/L = ......................................................... [1] (d) Quantities I and L are related by the equation 𝐼 = 𝑉 𝐿 × 𝑅𝑤 + 𝑉 𝑅1 where I is the current in the circuit, V is the e.m.f. of the battery, L is the position of the jockey on the resistance wire (in metres) Rw is the resistance of the full 1.000 m length of resistance wire, R1 is the resistance of resistor R. Using the same apparatus provided as the above experiment, plan an experiment to determine the values of Rw and R1. Your plan should include: • a description of how you would perform the experiment, • one precaution taken to ensure the accuracy of your experiment, • a statement of the graph that you would plot to test the relationship, • a sketch of the graph that you would expect to obtain, • an explanation of how you would obtain a value of the constant Rw and R1 from your graph if the suggested relationship is correct. [6] ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ………………………………………………………………………………………

Y4Exp Physics Preliminary Examination 2024 Page 6 of 11 ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [Total: 10]

Y4Exp Physics Preliminary Examination 2024 Page 7 of 11 Section B 3 In this experiment, you will investigate how the length of a wool string affects the time taken for a suspended rotating tube to come to a momentary