Sec 4 Physics SA2 2018 Ahmad Ibrahim

AHMAD IBRAHIM SECONDARY SCHOOL GCE O-LEVEL PRELIMINARY EXAMINATION 2018 PHYSICS PAPER 1 6091/01 Sec 4 Express Date: 16 August 2018 Duration: 1 hour Name: ………………………………………( ) Class: …………… READ THESE INSTRUCTIONS FIRST: Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class number and registration number on the optical answer sheet (OAS) provided. There are forty questions in this paper. Answer all questions. For each question, there are four possible answers, A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the optical answer sheet (OAS) provided. Read the instructions on the answer sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this question paper. The use of an approved scientific calculator is expected, where appropriate. This question paper consists of 20 printed pages 3

2 1 Pendulum A makes 20 complete oscillations in 10 s. Pendulum B makes 15 complete oscillations in 15 s. Both pendulums were displaced by a small angle before their oscillations. Which of the following statements must be true? A Pendulum B has a shorter period than pendulum A. B The string of pendulum B is longer than that of pendulum A. C The mass of the bob of pendulum B is smaller than that of pendulum A. D The angle of swing of release for pendulum B is smaller than that of pendulum A. 2 A pair of vernier calipers is used to measure the thickness of a coin. Diagram 1 shows the reading with the jaws closed. Diagram 2 shows the reading when the jaws are closed around the coin. What is the zero error and the actual thickness of the coin? Zero error / cm Corrected reading / cm A -0.02 4.05 B -0.02 4.01 C +0.08 3.95 D +0.08 4.11 cm cm Diagram 1 Diagram 2 4

3 3 A student uses a micrometer screw gauge to measure the diameter of a ball bearing. Diagram 1 shows the zero error of the gauge and diagram 2 shows the measurement of the diameter before it is corrected. Diagram 1 Diagram 2 What is the true diameter of the ball bearing? A 7.19 mm B 7.69 mm C 7.72 mm D 7.75 mm 4 A sphere runs along a smooth rail from P to Q as shown. Which of the following graphs best represents the variation of the distance d travelled by the sphere with time t? 5

4 5 A bicycle accelerates from a speed of 2.0 m/s to 10 m/s in 8.0 s. What is its average speed during the journey? A 4.0 m/s B 5.0 m/s C 6.0 m/s D 7.0 m/s 6 The diagram shows the graph of displacement s against time t for a body moving in a straight line. Which of the following shows the graph of speed v against time t for this body? 7 Two metal blocks are stacked one on top of the other as shown i n the diagram below. They are dropped in vacuum, falling together freely under earth ’s gravitational field. What is the net force acting on the 3 kg metal block during the fall? A 10 N B 20 N C 30 N D 40 N 6

5 8 The diagram shows a gas trapped in the left arm of a manometer containing mercury. If the atmospheric pressure is 760 mm Hg, what is the pressure of the trapped gas? A 80 mm Hg B 150 mm Hg C 680 mm Hg D 910 mm Hg 9 A beaker of liquid is placed under a bell jar. The pressure of the air above the liquid is reduced and some liquid evaporates. This causes the liquid to become colder. Why does the temperature of the liquid fall? A The air molecules blow away the liquid molecules. B The air molecules cool down the liquid. C The higher energy molecules leave the liquid. D There are fewer molecules of liquid in the beaker. 7

6 10 A hydraulic lift is used to support a car of weight 9000 N. Piston A has a cross-sectional area of 0.05 m 2 while piston B has a cross-sectional area of 2.0 m2. What is the force F needed to support the weight of the car? A 225 N B 450 N C 900 N D 3600 N 11 The outlet of a syringe is sealed and air is trapped in the syr inge. The temperature of the air is kept constant. Why does the pressure of the air increase when the piston is pushed from X to Y? A The air molecules are moving faster. B The collision between the air molecules increases. C The forces between air molecules increases. D The rate of collision of the air molecules with the wall increases. 9000 N car Force F Piston A 0.05 m2 Piston B 2.0 m2 Fluid 8

7 12 A mercury-in-glass thermometer is shown. What is the temperature when the mercury thread is at T? A 10 oC B 25 oC C 30 oC D 40 oC 13 Water of mass 0.87 kg at 90 ºC is poured into an insulated metal container of mass 0.50 kg at 20 ºC. The final temperature of water is 86.2 ºC. If the specific heat capacity of water is 4200 J kg-1K-1, what is the specific heat capacity of the metal in J kg-1K-1? A 360 B 380 C 420 D 480 14 Which statement about a fixed mass of gas is correct? A As pressure increases at constant temperature, the volume decreases. B As pressure increases at constant temperature, the volume increases. C As temperature increases at constant pressure, the volume decreases. D As temperature increases at constant volume, the pressure decreases. 15 What describes the volume and shape of a gas or liquid at constant temperature? A The volume of a gas is fixed but its shape is not fixed. B The volume of a gas is not fixed and its shape is not fixed. C The volume of a liquid is fixed and its shape is fixed. D The volume of a liquid is not fixed but its shape is fixed. 9

8 16 Air in a closed container contains smoke, illuminated by bright light. When viewed through microscope, bright specks of light are seen moving at random. Which statement is correct? A The random motion of the specks is faster in a vacuum. B The specks move faster when the air is at a higher temperature. C The specks seen are molecules of air in rapid random motion. D When the light is turned off, the specks slow down and stop moving. 17 The diagram shows four identical cans with their outside surface s painted either dull black or polished silver. Each can contains the same volume of water, initially at 80 °C. After five minutes in a cool room, which can contains the hottest water? A B C D 10

9 18 The diagram shows a vacuum flask and an enlarged view of a section through the flask wall. The main reason for the silvering is to reduce heat transfer by A conduction only. B conduction and convection. C radiation only. D radiation and convection. 19 A cook makes the pudding ‘baked Alaska’. The pudding is placed in a very hot oven until the top of the egg white turns brown. It is then removed from the oven. Why does the ice cream stay cold? A Air is a good conductor of heat and conducts the heat away from the ice cream. B Air is a poor conductor of heat and slows the heat from reaching the ice cream. C The metal dish is a good conductor of heat and conducts the heat away from the ice cream. D The metal dish is a poor conductor of heat and slows the heat from reaching the ice cream. 11

10 20 A ray of light is incident on one side of a rectangular glass block. The angle of refraction is 40° in the glass. The critical angle for light in glass is 42°. Which diagram shows the path of this ray? 21 The figure below shows the top view of an empty room with a vertical plane mirror M at the middle. Rachel stands at point P and looks into the mirror. Which object cannot be seen by Rachel in the mirror? 12