DIRECTORATE FOR QUALITY AND STANDARDS IN EDUCATION Department for Curriculum Management Educational Assessment Unit Track 2 Annual Examinations for Secondary Schools 2016 FORM 4 PHYSICS TIME: 1h 30min Name: Class: INFORMATION FOR CANDIDATES Where necessary take acceleration due to gravity g to be 10 m/s 2. The use of a calculator is allowed. The number of marks for each question is given in brackets at the end of each question. You may find these equations useful: Force F = m a W = m g Motion Electricity Waves total distance (u + v) t Average Speed = total time s = s = ut + 1 2 2 at2 v = u + at v 2 = u 2 + 2as Momentum = m v Q = I t V = I R E = Q V R L/A R TOTAL = R 1 + R 2 + R 3 real depth η = apparent depth v = f λ f = 1 T E = I V t 1 = 1 + 1 R TOTAL R 1 R 2 speed of light in air η = speed of light in medium magnification = h i image height = h o object height Others Area of triangle = 1 2 bh Area of Trapezium = 1 (a + b)h 2 INSTRUCTIONS TO CANDIDATES Use blue or black ink. Pencil should be used for diagrams only. Read each question carefully and make sure that you know what you have to do before starting your answer. Answer ALL questions. All working must be shown. This document consists of 10 printed pages. For Examiner s Use Only Question Max Mark 1 8 2 8 3 8 4 8 5 8 6 15 7 15 8 15 Written 85 Practical 15 Total 100 Physics Form 4 Secondary Track 2 2016 Page 1 of 10
SECTION A Each question carries 8 marks. This section carries 40 marks of the total marks for this paper. 1. Figure 1 shows a sound wave travelling through air from a loudspeaker to a human ear. Figure 1 a) On the diagram above, label a compression with a C and a rarefaction with an R. [2] b) Indicate, on the diagram, one complete wavelength using its correct symbol. [1] c) How many complete waves are shown in the diagram? _[1] d) The distance between the loudspeaker and the ear is 16.5 m. It takes 0.05 seconds for a sound wave to reach the ear. Calculate the speed of sound in air. e) Calculate the frequency in Hz of this sound wave. 2. A two euro coin rests at the bottom of a pool of water, as shown in Figure 2. Figure 2 a) On the diagram, draw the path followed by a ray of light from the coin to the eye. [2] b) Underline: The speed of the ray of light as it emerges into the air (increases, decreases, remains the same). The image of the coin is (real, virtual). [2] Page 2 of 10 Physics Form 4 Secondary Track 2 2016
c) Give ONE reason why the ray of light bends as it emerges from the water. d) The coin appears at a depth of 1.5 m when viewed from above. Given that the refractive index of water is 1.33, calculate the real depth of the pool of water. 3. Police use radar guns to determine the speed of cars along the road. The microwave beam emitted by the radar gun gets reflected off the moving car and the difference between the outgoing and the incoming frequencies of the microwaves is used to determine the speed of the car. a) Is it possible for a driver to see and avoid the microwave beam? Why? b) State ONE property that electromagnetic waves have in common. _[1] c) A radar speed trap shows a change of frequency of 3000 Hz when used to measure the speed of a car. Use the graph to find the speed of the car. [1] d) If the speed limit is 60 km/h, will the police issue a ticket to this car? Show your calculations. Figure 3 e) If the radar gun operates at a frequency of 10700 MHz, calculate the wavelength of the waves used. The speed of light is 300 000 000 m/s. Physics Form 4 Secondary Track 2 2016 Page 3 of 10
4. A car is driven along a straight road. The graph shows how the velocity of the car changes from the moment the driver sees a very slow-moving queue of traffic ahead. A B C Figure 4 a) Using the graph or otherwise, calculate the deceleration of the car between points A and B. b) Calculate the distance covered by the car in the first 10 seconds. c) Calculate the average speed of the car and draw a line to indicate this speed on the graph. d) After the 10 seconds shown on the graph, the driver accelerates and reaches a speed of 18 m/s in a distance of 200 m. Calculate the time it took the car to cover this distance. Page 4 of 10 Physics Form 4 Secondary Track 2 2016
5. Julia was investigating current flow through a lamp. Figure 5 a) In the space provided, draw the circuit diagram for this setup using the correct circuit symbols. [2] b) The resistance of the lamp when brightly lit is 15. Calculate the current in Amps flowing through the lamp if the potential difference measured by the voltmeter is 1.5 V. c) Another lamp that has double the resistance of the first lamp is connected in parallel to the first lamp. Calculate the total resistance of the two lamps. d) Underline: The voltmeter reading will (increase, decrease, remain the same) when the second lamp is connected in parallel to the first lamp. [1] e) Explain why a lamp does not obey Ohm s law. _[1] Physics Form 4 Secondary Track 2 2016 Page 5 of 10
SECTION B Each question carries 15 marks. This section carries 45 marks of the total marks for this paper. 6. Julia was investigating how the current through a coil of wire changes with the voltage across it. She sets up the apparatus as shown in Figure 6. a) The multimeter labelled X is being used as an and is connected in. [2] X Y b) The multimeter labelled Y is being used as a and is connected in. [2] c) Using numbers from 3 to 6, list in the correct order the steps Julia must take to carry out the experiment. Set the rheostat to maximum resistance. 1 Adjust the rheostat to a new resistance value. Switch on the circuit and take the initial current and voltage readings. 2 Record the voltage and current readings with the new rheostat setting. Plot a graph of Current against Voltage. Repeat the process a number of times to get at least five different readings. d) During the experiment the data was collected in the following table. Figure 6 Voltage V / V 0 1 2 3 4 5 6 Current I / A 0 0.2 0.4 0.6 0.8 1.0 1.2 Plot a graph of Current on the y-axis against Voltage on the x-axis. [4] [2] e) Use the graph to find the value of the i) current I in amps when the voltage is 3.5 V [1] ii) voltage V in volts when the current is 0.3 A [1] f) From the graph, calculate the resistance R in ohms of the wire. g) Does the resistance wire obey Ohm s law? _[1] Page 6 of 10 Physics Form 4 Secondary Track 2 2016
1.2 Graph of current I / A against voltage V / V 1.1 1.0 0.9 0.8 0.7 I / A 0.6 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 6 7 8 V / V Physics Form 4 Secondary Track 2 2016 Page 7 of 10
7. a) Peter was driving home after a very long day of work. He spots a hedgehog crossing the road and applies the brakes to stop just next to the hedgehog. A B C D E Figure 7 At A, Peter is travelling at a uniform velocity of 15 m/s. When he arrives at B he sees a hedgehog on the road at E. Peter starts to brake at C and finally comes to a complete stop at D. i) What is Peter s velocity at B? m/s. [1] ii) The time taken to cover the distance BC is called the time. [1] iii) Distance CD is the braking distance. Which distance is the stopping distance?. [1] iv) Name ONE factor which affects the distance BC. [1] v) Name ONE factor which affects the distance CD. [1] vi) The car came to a complete stop in 1.5 s. Calculate the deceleration of the car. [2] vii) If the total mass of Peter and his car is 900 kg, calculate the braking force applied. [2] A B Figure 8 b) An empty train cargo wagon of mass 10,000 kg is released from the engine and moves with a velocity of 4 m/s towards a stationary wagon of mass 30,000 kg. After collision the two wagons join together. Page 8 of 10 Physics Form 4 Secondary Track 2 2016
i) Calculate the momentum of wagon A before collision. [2] ii) What is the total momentum of the two wagons after collision? [1] iii) What is the total mass of the two wagons after collision? [1] iv) Calculate the common velocity with which the two wagons move after collision. [2] 8. Elizabeth and Neville are investigating the properties of a lens and a prism. a) Elizabeth shines a ray of white light through a prism. i) Complete the ray diagram to show how the red ray of the spectrum forms on the screen. Label clearly. [1] ii) What is this effect called? Glass Prism White Light Screen Figure 9 [2] iii) Name ONE example where this happens in nature. [1] blue b) Neville is given a converging lens. He uses it to focus a distant object on a screen. By using numbers from 2 to 5, arrange in order the steps he needs to follow to find an approximate value for the focal length of the lens. The convex lens is cleaned with a fine cloth. 1 A screen is placed behind the lens. Lens is placed facing a distant object. Screen is moved until a sharp image is obtained. The distance between the screen and lens is measured. Figure 10 [4] Physics Form 4 Secondary Track 2 2016 Page 9 of 10
c) Neville uses this lens to obtain a sharp image on a screen of an object that is placed in front of the lens. Scale: 1 square = 2 cm Figure 11 i) On the diagram above, mark the principal focus F of the lens. [1] ii) Calculate the focal length of the lens. [1] iii) Underline: The image of the object obtained on the screen is (real, virtual) and (upright, inverted). iv) Calculate the height of the image. [1] v) The magnification of a lens is found using the equation magnification = image height object height If the object height is 8 cm, calculate magnification of lens. [2] [2] Page 10 of 10 Physics Form 4 Secondary Track 2 2016