MI 2024 PU3 H2 PHYSICS PRELIM P4 QP

Class Adm No Candidate Name: This document consists of 17 printed pages and 3 blank pages. [Turn over 2024 Preliminary Exams Pre-University 3 H2 PHYSICS 9749 / 04 Paper 4 Practical 26 August Candidates answer on the Question Paper. 2 hours 30 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and admission number in the spaces provided at the top of this page. Write in dark blue or black pen on both sides of the papers. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. Answer all questions. Write your answers in the spaces provided in this 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 16 2 8 3 19 4 12 TOTAL / 55 H

2 1 This investigation considers the size of the hole needed in a salt shaker for the salt to flow at a suitable rate. (a) You have been provided with a beaker labelled P containing 100 g of salt as shown in Fig. 1.1. Fig. 1.1 (i) Measure and record the depth x of salt in beaker P using the vernier calipers. x = …………………………………. [1] (ii) State a significant source of error in your value of x. [1] (iii) Estimate the percentage uncertainty in your value of x. percentage uncertainty = …………………………………. [1] (b) You have been provided with two cards. Each card has a hole of a different size. (i) Measure and record the diameter d of the smaller hole. d = …………………………………. [1] (ii) Determine the area A of the smaller hole. A = …………………………………. [1] x beaker salt

3 [Turn over (c) (i) Fill the boiling-tube, as shown in Fig. 1.2, with salt from beaker P. Fig. 1.2 (ii) Cover the open end of the boiling-tube with the card that has the smaller hole. Use tape to attach the card to the boiling-tube. The hole should not be covered by tape. When the boiling -tube is inverted, it should not be possible for salt to leave the boiling-tube other than through the hole. (iii) Cover the hole with your finger. Invert the boiling-tube over the empty beaker Q. Remove your finger and allow the salt to flow through the hole into beaker Q for 50 seconds. It may be necessary to shake the boiling-tube gently to achieve constant flow. (iv) Tap beaker Q gently on the bench to ensure that the surface of the salt is level. Measure and record the depth y of salt in beaker Q. y = ……………………………………… (v) Estimate the mass m of salt in beaker Q. m = …………………………………. [1] boiling-tube salt

4 (d) The recommended daily intake of salt for an adult is 5 g. Use your data to calculate the time that a shaker, with a hole the same size as that in (c)(ii) should be inverted to apply 5 g of salt to food. time = …………………………………. [1] (e) It is suggested that the rate of flow R of salt is proportional to the area A of the hole. Use the card with the larger hole to take further measurements in order to investigate this suggestion. State and explain whether or not you agree with this suggestion. Present your measurements and calculated results clearly. [6]

5 [Turn over (f) A statement found on the internet says that: "The salt shaker may be distinguished primarily by the size of the holes, and then by the number of holes. Salt is coarser than pepper, and needs the larger hole. It is also heavier and flows much more freely than pepper, accordingly there are often fewer holes on the salt shaker to help control the flow. However, there is no manufacturing standard." Suggest changes that could be made to the salt investigation to study the flow of pepper from a shaker. [3] [Total: 16 marks]

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7 [Turn over 2 In this experiment, you will determine the length of a metal in the form of a wire. (a) Measure and record the diameter d of the short sample Y that is attached to the cardboard tube. d = [1] (b) Setup the circuit as shown in Fig. 2.1. (i) Set the rheostat to its maximum resistance. (ii) Close the circuit. Measure the current I and the potential difference V across sample Y. I = V = [1] (iii) Open the circuit Fig. 2.1 A V ammeter voltmeter sample Y rheostat

8 (iv) Vary the resistance of the rheostat and repeat (b)(ii), (b)(iii) until you have 3 more sets of I and V. [2] (c) Plot your values from (b)(iv) on Fig. 2.2. [2] Fig. 2.2 V/ V I / mA [2]

9 [Turn over (d) The ratio of the graph represents the resistance of the sample Y . Given that the resistance is given by R= L A  where ρ is the resistivity of the metal from which the wire is made, L is the length of the wire and A is its cross-sectional area. The resistivity of the given wire is 4.50 x 10-7 Ω m. Estimate the length of the sample. L = [2] [Total: 8 marks]

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