NYGH-2021-S4-EOY-Physics-P2

Class Register Number Name End-of-Year Examination 2021 Secondary 4 PHYSICS Paper 2 1 hour 45 minutes Thursday 7 October 1100 – 1245 No Additional Materials are required READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name, register number and class 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. Section A (40 marks) Answer all questions. Section B (30 marks) Answer all questions including questions 12, 13 and 14 Either or 14 Or. Circle question 14 Either or 14 Or in the grid on the right to indicate which question you have answered. INFORMATION FOR CANDIDATES You are reminded that all quantitative answers should include appropriate units. The use of an approved scientific calculator is expected, where appropriate. Show all your working in a clear and orderly manner, as more marks are awarded for sound use of Physics than for correct answers. You are advised to spend no longer than one hour on Section A and n o longer than 45 minutes on Section B. The number of marks is given in brackets [ ] at the end of each question or part question. Take the acceleration due to gravity g (or gravitational field strength) to be 10 m s-2 (or 10 N kg-1) near the Earth’s surface. Examiner’s Use Paper 2 (70 marks) Section A 1 2 3 4 5 6 7 8 9 10 11 Section B 12 13 14 E 14 O Total Paper 1 (30 marks) Overall 100 This document consists of 19 printed pages and 1 blank page. Setter(s): AJL & MS NANYANG GIRLS' HIGH SCHOOL [Turn over

2 Section A Answer all questions in this section. 1 Two cars start from rest at the same point along a straight racetrack. Car A starts from rest and accelerates constantly. Car B accelerates rapidly for 3.0 s and then maintains a constant speed. Fig. 1.1 (a) Determine the acceleration of car A. acceleration of car A = ………………………… [1] (b) Calculate the time at which the two cars have the same speed. time = ………………………… [2] (c) Given that the winning car crosses the finish line at t = 6.5 s, determine which car has won the race. Show all necessary calculations. Car …………. has won the race. [3] speed / m s-1 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0 30 10 20 time t / s car A car B

3 [Turn over 2 A mechanic wants to turn a nut by applying a 20 N force to a spanner as shown in Fig. 2.1. Fig. 2.1 (a) Determine the moment of the force applied by the mechanic. moment of the force = …………………..………… [1] direction of the moment = …………..………………… [1] (b) State one way in which the mechanic could apply the same turning moment to the nut by using a smaller force. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ……………………………………………………………………………………………… [1]. 3 Fig. 3.1 shows an iron cube and an aluminium cube. The iron cube, of length 2.0 cm, has a density of 7.9 g cm-3. The aluminium cube, of length 3.0 cm, has a density of 2.7 g cm-3. Fig. 3.1 The two cubes are melted to form an alloy. Calculate the density of this alloy. density of alloy = …………………………………… [2]. 200 mm 20 N nut spanner 2.0 cm 3.0 cm iron cube aluminium cube 50

4 4 A thin L-shaped tube traps a 150 mm length of air with a fixed length of mercury thread when it is held as shown in Fig. 4.1. The tube is sealed at one end and open to the atmosphere at the other. Fig. 4.1 (a) If atmospheric pressure is 76.0 cm Hg, calculate the pressure of the trapped air in cm Hg. pressure of trapped air = …………………………… [1]. The L-shaped tube is then rotated through 90º clockwise to the position shown in Fig. 4.2, such that the trapped air is reduced in length to 125 mm. Fig. 4.2 (b) Calculate the length of mercury in the vertical tube, X, above the 125 mm of trapped air. X = …………………………… [2]. mercury sealed end of tube open end of tube trapped air 7.0 cm 150 mm mercury trapped air X 125 mm

5 [Turn over 5 An optical fibre has an inner glass core surrounded by an outer glass cladding. Fig. 5.1 shows the path of a ray of light travelling along the fibre, striking the boundary between the core and the cladding at an angle . The refractive indices of the core and the cladding are 1.60 and 1.10 respectively. Fig. 5.1 (a) Explain the purpose of surrounding the glass core with the outer glass cladding shown in Fig. 5.1. ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... .................................................................................................................................. [2] (b) State the angle of incidence of the light ray at the boundary between the core and the cladding if the angle  is 35º. angle of incidence = .................................... [1]. (c) Determine the maximum value of  for which the light ray will remain within the inner glass core. maximum angle of  = .................................... [2]. core n = 1.60 cladding n = 1.10 cladding n = 1.10    

6 6 A convex lens L forms an image I of a point object O placed on the principal axis, as shown in Fig. 6.1. The diagram is not drawn to scale. Fig. 6.1 (a) Calculate the focal length of the lens L. focal length = .................................... [1]. (b) If the point object O is raised 5.0 cm vertically above the principal axis, determine the new position of the image. Show any working clearly. Mark and label the position of this new image I’ on Fig. 6.1. [2] (c) If the object O on the principal axis (in Fig. 6.1) is moved a short distance further from the lens, state what would happen to the position of this image. ....................................................................................................................................... .................................................................................................................................. [1] O L I 40.0 cm 20.0 cm

7 [Turn over 7 The waves made by earthquakes are recorded by an instrument called a seismometer shown in Fig. 7.1. Fig. 7.1 Fig. 7.2. shows a trace of the waves recorded by the seismometer during an earthquake. Fig. 7.2 (a) Describe any change in the wave shown in Fig. 7.2 during the 20 seconds. .................................................................................................................................. [1] (b) Calculate the frequency of the wave shown in Fig. 7.2. frequency = .................................... [1]. graph paper on rotating drum large mass pen fixed to the large mass 20 seconds

8 8 Two identical metal spheres, X and Y, are given opposite charges of different magnitudes as shown in Fig. 8.1. Fig. 8.1 A conducting wire is connected between the two spheres. (a) Sta