NYGH-2022-S4-EOY-Physics-P2

Class Register Number Name End-of-Year Examination 2022 Secondary 4 PHYSICS Paper 2 Theory 1 hour 45 minutes Tuesday 11 October 1015 – 1200 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 11, 12 and 13 Either or 13 Or. Circle question 13 E or 13 O 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 no 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 Section B 11 12 13 E 13 O Total Paper 1 (30 marks) Overall 100 This document consists of 19 printed pages and 1 blank page. Setters: GHP & AWL NANYANG GIRLS' HIGH SCHOOL [Turn over

2 Section A Answer all questions in this section. 1 A bob of mass 2.0 kg is suspended by a string at P. The bob is pulled to one side by a horizontal spring balance, as shown in Fig. 1.1. The string is now inclined at 40 ° from the vertical. Fig. 1.1 (a) On Fig. 1.1, draw and label the direction of the tension acting at point Q along the string PQ. [1] (b) In the space below, draw a scaled vector diagram to determine the magnitude of the tension in the string PQ. State the scale used. scale ………………………… tension = ………………………… [3] spring balance Q 2.0 kg P 40°

3 [Turn over 2 A uniform plank of length 2.00 m and mass 4.0 kg has markings at equal length intervals painted on it, as shown in Fig 2.1. The plank is supported by two trestles A and B, and a student of mass 52.0 kg stands on the plank. Fig. 2.1 (a) On Fig. 2.1, draw and label the weight of the plank. [1] (b) Calculate the force exerted by trestle B on the plank. force = ………………………… [2] (c) Calculate the force exerted by trestle A on the plank. force = ………………………… [1] A B 40 cm

4 3 A woman of mass 70 kg makes a bungee jump as shown in Fig. 3.1. She starts her jump from a bridge above a river. The unstretched length of the light elastic cord is 50 m. For this question, assume that air resistance and the height of the woman is negligible. Fig. 3.1 (not drawn to scale) At position A, she falls off the bridge from rest. From position B, the cord stretches. She comes to a momentary stop for the first time at position C before moving upwards. Position D is her final rest position. (a) Determine her speed at position B. speed = ………………………… [2] (b) Determine the elastic potential energy of the cord when she is at position C. energy = ………………………… [1] (c) The elastic potential energy of the cord at position D is smaller than the value you have calculated in question (b). Suggest a reason for this. ………………………………………………………………………………………………… ……………………………………………………………………………………………… [1]. bridge D A B C 80 m 50 m 58 m 74 m elastic cord river

5 [Turn over 4 Fig. 4.1 shows a partially inflated helium balloon leaving the ground to take scientific instruments high up in the atmosphere. Fig. 4.1 A completely deflated balloon contains no gas. The helium to inflate it is stored in a very large cylinder at a pressure 3.0 × 107 Pa. Helium that occupies a volume of 20 m3 in the cylinder is slowly released into the balloon until the pressure in the balloon is 1.0 × 10 5 Pa. The temperature of the helium remains constant. Assume the mass of the balloon to be negligible. (a) Calculate the volume of the helium gas in the partially inflated balloon. volume = ………………………… [2] (b) As the partially inflated helium balloon rises up, the volume of the balloon increases due to lower atmospheric pressure at greater height . Assume the temperature of helium remains constant. Applying the kinetic theory of matter and considering the helium molecules inside the balloon, explain why the pressure of the gas decreases as the balloon rises. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ……………………………………………………………………………………………… [2].

6 5 Fig. 5.1 shows an object at O placed in front of a thin converging lens. The positions of the focal points of the lens are marked F. Fig. 5.1 (a) On Fig. 5.1, draw two rays from the tip of the object to find the position of its image. Label the foot of the image as I. [3] (b) The lens is moved closer to the object. Describe one change to the image observed. ………………………………………………………………………………………………… ……………………………………………………………………………………………… [1]. lens O F F

7 [Turn over 6 A light uncharged conducting sphere R which is suspended on an insulating string is in contact with an uncharged metal sphere S . A positively charged sphere T is moved towards S as shown in the Fig. 6.1 below. (a) On Fig. 6.1, draw the charge distribution on R and S. [2] (b) Sphere T is brought into contact with sphere S. Describe the movement of charges and explain what happens to sphere R. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… ……………………………………………………………………………………….……… [2] 7 A resistance wire made from material X has a resistance of 5.0 Ω per metre. (a) Determine the effective resistance when two pieces of wire made from material X, each 3.0 m long are connected in parallel. effective resistance = …………..……….. [2] (b) If the diameter of the wire is 0.50 mm, calculate the resistivity of the material used to make the wire. resistivity = …………..……….. [2] S T insulating stands + + + + + + + + R Fig. 6.1

8 8 Two lamps of ratings 30 W, 12 V and 50 W, 12 V are connected in series to a 12 V battery as shown in Fig 8.1. (a) Explain why both lamps do not light up with normal brightness. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ……………………………………………………………………………………….……… [1] (b) Determine the current through the ammeter. current = ………………… [2] (c) Hence, or otherwise, determine the amount of electrical energy dissipated in the lamps if the above circuit is switched on for 5.0 minutes. energy = ………………… [2] 12 V 30 W, 12 V 50 W, 12 V Fig. 8.1 A

9 [Turn over (d) A rheostat is connected in parallel to the 50 W lamp. State what happens to the brightness of the 30 W lamp as the rheostat’s resistance is reduced. ………………………………………………………………………………………………… ……………………………………………………………………………………….……… [1] 9 Magnetic forces can be attractive or repulsive. When a n unmagnetised iron pin is brought close to a permanent magnet, it is always attracted to the magnet. Explain why. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… ……………………………………………