SJI 2018 Prelim P1

ST JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2018 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER PHYSICS Paper 1 Additional Materials: Multiple Choice Answer Sheet 6091/01 28 August 2018 1 hour (08:00 – 09:00) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number in the spaces provided. There are forty questions on 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 reco rd your choice in soft pencil on the separate Multiple Choice Answer Sheet. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done on this booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 15 printed pages including this cover page. [Turn Over

2 1 Fig 1.1 shows a micrometer screw gauge when it is fully closed. Fig. 1.2 shows the micrometer screw gauge when measuring the thickness of a metal sheet. Fig 1.1 Fig 1.2 What is the correct reading for the thickness of the metal sheet? A 5.45 mm B 5.50 mm C 5.55 mm D 5.95 mm 2 One oscillation of a swinging pendulum occurs when the bob moves from X to Z and back to X again. Y is the middle point of the oscillation. The first time the pendulum passes through Y, a stopwatch is started. How many times would the pendulum pass through Y to go through 20 oscillations? A 20 B 21 C 41 D 42 3 An object is thrown vertically upward. If air resistance is negligible, what is the acceleration and the velocity of the object when it is at the highest point? acceleration velocity A 10 m/s2  Max  B 10 m/s2  Max  C 10 m/s2  0 m/s D 0 m/s2  0 m/s X Z mm mm

3 4 An object is released from rest from a height above the ground. If air resistance acts on the object, which graph correctly shows the motion of the object? A B C D 5 A crane lifts a 20 kg object from rest. The object moves upward at a constant acceleration of 4.0 m/s2. What is the tension of the crane acting on the object? A 80 N B 120 N C 200N D 280 N 6 The figure below shows a uniform plank of negligible mass of length L, pivoted at P. Two downward forces, F and 30 N act on the two ends such that the plank is horizontal. What is the magnitude of the force acting on the plank at the pivot? A 24 N B 60 N C 120 N D 150 N v/m/s t/s v/m/s t/s s/m t/s s/m t/s 0.80 L 30 N F P

4 7 A book of weight, W slides along a smooth table-top until it falls off from the edge of the table at time, T. The figure below shows the path of the book. Which graph shows how the resultant force acting on the book changes with time? Neglect air resistance. A B C D 8 A beaker is filled with 45.0 cm3 of liquid of density 0.800 g/cm3. The total weight of the beaker and the liquid is 1.04 N. What is the mass of the beaker without the liquid? A 36.0 g B 46.8 g C 68.0 g D 104 g Fr/N t/s W T Fr/N t/s W T Fr/N t/s W T Fr/N t/s W T

5 9 A rigid L-shaped iron bar is pivoted at point P. Three forces act o n the lever arm as shown in the diagram. Assuming that the iron bar itself is weightless, what is the magnitude of the resultant moment of these forces about point P? A 2.0 Nm B 14 Nm C 18 Nm D 38 Nm 10 A square metal plate lamina of uniform mass have two holes drilled onto it as shown in the diagram. In which region is the centre of gravity of the square metal plate lamina most likely to be? 11 A 20 kg wooden cuboid of dimension 5.0 cm x 10.0 cm x 20.0 cm rests on a table. What is the possible maximum pressure the cuboid is able to act on the table? A 1.0 kPa B 4.0 kPa C 10 kPa D 40 kPa A B C D

6 12 The figure below shows a gas tap connected to 2 manometers. One of the manometers is filled with liquid X while the other is filled with water. Which statement best explains why the difference in the l evels of liquid X and the difference in the levels of water are not equal? A The gas tap is nearer to the manometer filled with water. B The density of liquid X is smaller than the density of water. C The gas pressure acting on water is larger than the gas pressure acting on liquid X. D The tube of the manometer filled with water is thicker than the tube of the manometer filled with liquid X. 13 A 5 cm long mercury thread is used to enclose methane gas in a test tube. Which orientation of the test tube will result in maximum pressure of the enclosed methane gas? A B C D gas tap liquid X water 5 cm 5 cm 5cm

7 14 A 1000 kg space shuttle moves vertically upwards into space at a constant speed of 50 m/s. If the air resistance acting on the space shutt le is 1200 N, what is the power of the space shuttle engine? A 60 kW B 440 kW C 500 kW D 560 kW 15 Object A is connected to object B by a taut string as shown in the figure below. A force is applied to object A to keep both objects at rest. When the force is released, object B moves vertically downwards while object A slides along the surface of the ramp. If the surface of the ramp is rough, which statement is correct? A loss in GPE of object B = gain in KE of object A B loss in GPE of the whole system = gain in KE of the whole system C gain in GPE of object A + gain in KE of object A = work done by object A against friction D loss in GPE of the whole system = gain in KE of the whole system + work done by object A against friction 16 Heat sinks are installed in electrical appliances to absorb and dissipate heat quickly. Which of the following characteristics are suitable for a good heat sink? A It has a low heat capacity and small surface area B It has a low heat capacity and large surface area C It has a high heat capacity and small surface area D It has a high heat capacity and large surface area 17 Sphere A has a higher temperature than sphere B. Which of the following methods does not help to increase the rate of heat transfer via radiation from A to B? A Coat sphere B with black paint. B Connect both spheres with a shiny metal rod. C Roughen the surface of sphere A. D Decrease the temperature of sphere B with an ice pack. A B

8 18 When a foot is placed in water of a certain temperature , it feels colder than it does when it is in air at the same temperature. What is the reason for this? A Air is a better conductor of heat than water. B Water is a better conductor of heat than air. C Convection current is formed in water and cool the foot further. D The foot absorb infrared radiation in air. 19 A small balloon is tied to a brick and is submerged into a container containing hot water. The water is allowed to cool. During the cooling process, the change in the density of the water is negligible. What will happen to the average velocity and the frequency of the air particles in the balloon colliding with the wall of the balloon? average velocity frequency of collision A decreases decreases B decreases increase C decreases constant D increases constant 20 The graph below shows the heating curve of an unknown liquid. What happens to the internal potential energy (IPE) and the internal kinetic energy (IKE) of the unknown liquid between AB and BC? between A and B between B and