PLMGSS 2022 4NA ScPhy Prelim P2

[Turn Over CANDIDATE NAME CLASS . INDEX NUMBER SCIENCE (Physics) 5105/02 Paper 2 Physics 3 August 2022 (Taken together with Paper 1) 1 hour 15 minutes Candidates answer on the Question Paper. No additional materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on the front cover. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A (14 marks) Answer all questions. Write your answers in the spaces provided on the question paper. Section B (16 marks) Answer any two questions. Write your answers in the spaces provided on the question paper. Enter the question number in Section B that you have answered on the lines in the grid below. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Only Paper Number Marks Paper 1 / 20 Paper 2 Section A / 14 Paper 2 Section B / 16 Q _____ Q _____ Total / 50 This document consists of 11 printed pages (including this cover page). Paya Lebar Methodist Girls’ School (Secondary) Preliminary Examination 2022 Secondary 4 Normal Academic

2 [Turn Over SECTION A (14 marks) Answer all questions in this section. 1. The following graph shows the motion of two cyclists. (a) State which cyclist, A or B, slows down faster. ……………………….. [1] (b) Calculate the acceleration of cyclist B. acceleration = …………………… m/s2 [2] B A

3 [Turn Over 2. Three blocks, A, B and C are placed on three inclined planes as shown. A B C (a) Mark an ‘X’ at the pivoting point of block B. [1] (b) State which block(s), A, B or C will not topple. Explain your answer. ………………………………………………………………………………………….. ……………………………………………………………………………………… [2] 3. A battery is connected to two identical light bulbs, P and Q and a resistor R as shown in the diagram below. (a) Define e.m.f. ………………………………………………………………………………………….. ……………………………………………………………………………………… [1] (b) The current in light bulb P is 0.15 A. Calculate the current in resistor R. Current in resistor R = ……………………. A [2] R P Q

4 [Turn Over 4. The diagram shows a boy and a man standing on skateboards at the top of a track. The total weight of the boy and his skateboard is 500 N. The total weight of the man and his skateboard is 800 N. (a) Calculate the work done by the boy in carrying his skateboard from the bottom to the top of the stairs. Work Done = ……………………. J [2] (b) Assuming there is no energy loss due to friction, calculate the speed of the man at C. Take g = 10 N/kg. Speed = ……………………. m/s [2] (c) Suggest what should the boy do to reach E. ………………………………………………………………………………………….. ……………………………………………………………………………………… [1] END OF SECTION A 3 m A B C D E

5 [Turn Over SECTION B (16 marks) Answer any two questions from this section in the spaces provided 5. Sound travels in the form of longitudinal waves. (a) Define longitudinal waves. …………………………………………………………………………………………. ……………………………………………………………………………………… [1] (b) In an experiment, a vibrating tuning fork is placed in front of a microphone. The microphone is connected to a piece of apparatus that shows waveforms. The output trace, A, from the microphone is shown on the screen of the apparatus as seen below. trace A The controls of the apparatus are not altered throughout the experiment. (i) The same tuning fork is made to produce a softer sound. Sketch on the diagram below the output trace, B, seen on the screen for the softer sound. trace B [1]

6 [Turn Over A different tuning fork is placed in front of the microphone. It is made to produce the same volume of sound as that originally produced by the first tuning fork. The output trace, C, is seen on the screen as shown below. trace C (ii) Explain the difference between trace A and trace C. ………………………………………………………………………………….. ……………………………………………………………………………… [1] (c) The loudness of sound is measured in decibels (dB). A loudspeaker produces a loud sound. A sound meter is used to measure the loudness of the sound as it is moved away from the loudspeaker. The results obtained are shown in the table below. Distance/ m 1.0 2.0 4.0 6.0 8.0 12.0 Loudness/ dB 100 90 80 74 70 68 (i) Plot a graph of loudness against distance, marking each point with a cross, (x). [1] (ii) Draw a curved line of best fit, taking into account all the points. [1] 60 70 80 0 90 100 2.0 4.0 6.0 8.0 10.0 12.0 14.0 0 Loudness /dB Distance /m

7 [Turn Over (iii) A man stands 3.0 m from the loudspeaker. Use your graph to find how loud the sound is at this distance. Loudness of sound = ………………… dB [1] (iv) The table shows the maximum length of time that is safe for a person to experience a continuous sound. Continuous sound/ dB Maximum length of time 79 32 hours 82 16 hours 85 8 hours 88 4 hours 91 2 hours 94 1 hour 97 30 minutes Estimate the length of time for which it is safe for the man to stand 3.0 m away from the loudspeaker whilst it is making the sound. Length of time = ……………………… [1] (v) Suggest one way in which the man could safely extend this time. ………………………………………………………………………………….. ……………………………………………………………………………… [1]

8 [Turn Over 6. A student carries out an experiment to study the relationship between potential difference (p.d.) across a resistor, R, and the current flowing through it. The student uses the circuit shown below. (a) (i) Name the component labelled X. ………………………………………. [1] (ii) State the purpose of the component labelled X. ………………………………………………………………………………….. ……………………………………………………………………………… [1] The student adjusts component X until the voltmeter reads 0.20 V. He then records the current reading. By adjusting component X four more times, the student obtains the results shown below. (b) Use one row of data from the table above to calculate the resistance of resistor R. Resistance = ……………………. Ω [1] p.d. reading/ V Current reading/ A 0.20 0.10 0.40 0.20 0.60 0.30 0.80 0.40 1.00 0.50 X 2.00 V R

9 [Turn Over (c) (i) State the upper limit of the voltmeter reading. Upper Limit = ………………. V [1] (ii) Suggest why this voltmeter reading has an upper limit. ………………………………………………………………………………….. ……………………………………………………………………………… [1] The student now replaces the voltmeter to measure the potential difference across component X as shown below. Once again, he adjusted component X to obtain several new readings. (d) Complete the table below to show the new voltmeter and ammeter readings. p.d. reading/ V Current reading/ A 1.80 0.10 1.40 0.50 [2] (e) Household circuits contain earth, live and neutral wires. State which wire must fuses be connected to. ……………………………………………………………………………………… [1] 2.00 V

10 [Turn Over 7. The diagram shows a drone hovering