2022 SNGS Physics Prelim P2 QP

1 SNGS Sec 4 Physics Prelim P2 2022 Name ___________________________ ( ) Class ______________ PRELIMINARY EXAMINATION GENERAL CERTIFICATE OF EDUCATION ORDINARY LEVEL PHYSICS 6091/02 Paper 2 Theory 24 August 2022 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name and index number on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams or graphs. Do not use highlighters, correction fluid or correction tape. Section A Answer all questions. Section B Answer all questions. Question 12 has a choice of parts to answer. Students are reminded that all quantitative answers should include appropriate units. The use of approved scientific calculator is expected, where appropriate. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of Physics than for correct answers. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 22 printed pages. [Turn over] For Examiner’s Use Section A (50 Marks) Section B (30 Marks) Total (80 Marks)

2 SNGS Sec 4 Physics Prelim P2 2022 1 Fig. 1.1 shows a water wheel used in a farm. Water entering at the top turns the wheel about the hub. Fig. 1.1 Point C on the wheel moves in a circular path at a constant speed of 2.5 m/s. (a) (i) State the change in speed of point C as it moves to position D, change in speed =………………….. [1] (ii) Determine the magnitude of the change in velocity of point C as it moves to position D, change in velocity =…………………. [1] (b) The farmer installs a laser counter at L to track the rotation of the wheel. The counter records the time interval between two spokes as the wheel rotates, as shown in Fig. 1.2. time / s 1.48 1.51 1.50 1.49 1.52 Fig. 1.2 Determine the frequency of rotation of the wheel. frequency of rotation = ………………………. [2] water in hub C D L spokes

3 SNGS Sec 4 Physics Prelim P2 2022 2 A bob of mass 0.500 kg falls from rest at a given height and strikes a pond. Fig. 2.1 shows the variation of velocity of the bob with time during its motion. The bob reaches the bottom of pond at R. The gravitational field strength of Earth is 10 N/kg and air resistance is assumed to be negligible. Fig. 2.1 (a) Determine the acceleration of the bob for the first 1. 5 s of its descent. acceleration = ………………. [1] (b) Explain how a student can use Fig. 2.1 to estimate the depth of the pond. ……………………………………………………………………………. ……………………………………………………………………………. [1] velocity 0.5 0.0 time / s 5.0 10.0 15.0 1.0 1.5 2.0 2.5 0.0 3.0 P Q R m/s _______

4 SNGS Sec 4 Physics Prelim P2 2022 (c) On Fig. 2.2, sketch a graph to show the displacement of the bob with time for t = 0.0 s to t = 3.0 s. Displacement is measured from the point the bob starts to fall. Fig. 2.2 [2] (d) Describe the energy changes of the bob from position P to Q. ……………………………………………………………………………. ……………………………………………………………………………. [1] (e) Fig. 2.3 shows the bob when it is at a position between PQ. Fig. 2.3 Draw and label on Fig. 2.3 all the forces acting on it. [2]

5 SNGS Sec 4 Physics Prelim P2 2022 3 An object made up of a pencil and penknife is used in a balancing trick as shown in Fig 3.1. Fig. 3.1 (a) State what is meant by centre of gravity of an object. ……………………………………………………………………………. ……………………………………………………………………………. [1] (b) Mark a possible position for the centre of gravity for the object with ‘X’ on Fig 3.1. [1] (c) Explain why the object is in stable equilibrium. ……………………………………………………………………………. ……………………………………………………………………………. [1] (d) A student removes the penknife. She tries to balance the pencil alone. State and explain what will happen to the pencil. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. [2] pencil penknife pivot

6 SNGS Sec 4 Physics Prelim P2 2022 4 Fig. 4.1 shows a water manometer used to measure the pressure inside a gas pipe. Fig. 4.1 Fig. 4.2 (a) Explain how the manometer in Fig 4.1 shows that the pressure inside the gas pipe is greater than the atmospheric pressure. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. [2] (b) Calculate the pressure of the gas inside the pipe, given that the density of water is 1000 kg/m3, the gravitational field strength is 10 N/kg and the atmospheric pressure is 1.0 × 105 Pa. pressure = ………………… [2] (c) The manometer shown in Fig. 4.2 is connected to the same gas pipe at the same pressure as shown in Fig. 4.1. On Fig. 4.2, draw the levels of the liquid in the manometer if the manometer contains a liquid with density half that of water and has twice the diameter of the manometer in Fig. 4.1. scale in cm scale in cm [1]

7 SNGS Sec 4 Physics Prelim P2 2022 5 A negatively charged metal ball X is suspended from an insulating thread. An uncharged metal plate Y is mounted on an insulating stand. Fig. 5.1 Fig. 5.2 When X is brought near to Y, it is attracted towards Y as shown in Fig. 5.1. (a) On Fig. 5.1, draw the charges induced on Y. [1] (b) On Fig. 5.1, draw the electric field in the space between the two conductors. [1] (c) Explain why X is attracted to Y. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. [2] - - - - - - X Y Y X

8 SNGS Sec 4 Physics Prelim P2 2022 (d) Y is earthed momentarily as shown in Fig. 5.2. State and explain whether X will move closer, further or remains unchanged. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. [2] 6 Fig. 6.1 shows a light ray ABC from the top of an object passing through a lens. Fig. 6.1 (a) State and explain whether the lens is converging or diverging. ……………………………………………………………………………. ……………………………………………………………………………. ……………………………………………………………………………. [2] (b) Draw light ray(s) from the object so that the image of the object can be located. Draw the image and label the image I. [2] (c) Locate the position of the principal focus of the lens and label the position F. [1] Lens O principal axis A C B

9 SNGS Sec 4 Physics Prelim P2 2022 7 In the circuit shown in Fig. 7.1, a battery of e.m.f. 12 V is connected to resistors A and B, and component C. The I - V characteristic graphs for B and C are shown in Fig. 7.2. Fig. 7.1 Fig. 7.2 (a) Describe how the resistance of component C changes as the potential difference (p.d.) increases from zero.