NJC 2025 H2 Physics Prelim P1 QP

[Turn over NATIONAL JUNIOR COLLEGE SENIOR HIGH 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME SUBJECT CLASS REGISTRATION NUMBER PHYSICS Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9749/01 24 September 2025 1 hour READ THE INSTRUCTION FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, subject class and registration number on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty 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 record your choice in soft pencil on the separate Answer Sheet. 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 booklet. The use of an approved scientific calculator is expected, where appropriate. The OAS index number is in a 5-digit format. The 5-digit format is as follows: 1st digit and the last four digits of the Reg Number. e.g. 2005011 becomes 25011 This document contains 13 printed pages and 3 blank pages. H

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4 1 What is the order-of-magnitude of the mass of twelve one-dollar ($1) Singapore coins? A 100 g B 101 g C 102 g D 103 g 2 A student takes measurements to calculate the density of a liquid in a beaker. The height of the liquid is 0.20 m ± 2%. The internal diameter of the beaker is 0.05 m ± 3%. The mass of the liquid is 0.36 kg ± 10%. What is the percentage uncertainty in the calculated density of the liquid? A 2 % B 5 % C 15 % D 18 % 3 A student throws a stone upwards at an initial speed of 15.0 m s−1. What is the displacement of the stone after 2.00 s? A 1.12 m B 10.4 m C 11.5 m D 12.6 m 4 A student pulls a 2.0 kg crate with a force of 9.0 N directed at an angle 45° from the horizontal as shown in the diagram. A frictional force of 2.0 N acts between the crate and the ground. What is the acceleration of the crate? A 2.2 m s−2 B 3.2 m s−2 C 3.5 m s−2 D 4.5 m s−2 5 Two frictionless trolleys move along the same straight line towards one another. Their masses and velocities before collision are shown. The trolleys collide and stick together. What is the final kinetic energy of the trolleys after the collision? A 0.71 J B 14 J C 31 J D 35 J ground 45° 9.0 N crate

5 [Turn over 6 A spring hangs from the ceiling of a stationary train and a 1.2 kg mass is hung on the spring. The mass causes an extension of 2.4 cm on the spring when it is hung vertically. What is the extension of the spring when the train accelerates horizontally at a rate of 5.0 m s−2? A 1.2 cm B 2.6 cm C 2.7 cm D 3.6 cm 7 A spindle is attached at one end to the centre of a lever 1.20 m long and at its other end to the centre of a disc of radius 0.20 m. A cord is wrapped round the disc, passes over a pulley and is attached to a 900 N weight. What is the minimum force F, applied to each end of the lever, that could lift the weight? A 75 N B 150 N C 300 N D 950 N 8 A turbine at a hydroelectric power station is situated at a vertical distance 30 m below the level of the surface of a large lake. The water passes through the turbine at a rate of 5.7 m3 s−1. The overall efficiency of the turbine and generator system is 90%. The density of water is 1000 kg m-3. What is the useful power output of the power station? A 0.15 MW B 1.5 MW C 1.7 MW D 90 MW 9 A small coin of mass 10 g is placed on a horizontal rotating disc at a distance of 5.0 cm from the centre of the disc. The maximum frictional force between the coin and the disc is 0.20 N.

6 What is the largest angular velocity that the disc can have without coin slipping? A 0.060 rad s-1 B 1.0 rad s-1 C 20 rad s-1 D 400 rad s-1 10 An astronaut of mass m in a spacecraft experiences a gravitational force F = mg when stationary on the launchpad. The spacecraft is launched vertically upwards with an acceleration of 0.2g. What is the gravitational force on the astronaut immediately after launch? A 1.2mg B mg C 0.8mg D 0 11 The gravitational field strength at the surface of Neptune is approximately equal to the gravitational field strength at the surface of the Earth. The mass of Neptune is 17 times the mass of the Earth. What is the value of the ratio 𝑟𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝑁𝑒𝑝𝑡𝑢𝑛𝑒 𝑟𝑎𝑑𝑖𝑢𝑠 𝑜𝑓 𝐸𝑎𝑟𝑡ℎ ? A 0.059 B 0.24 C 4.1 D 17 12 A huge block of ice at 0°C with a hollow in its top surface is placed in an insulated container as illustrated. A mass of 160 g of water at 100°C is poured into the hollow. The water has a specific heat capacity 4.20 kJ kg−1 K−1 and ice has a specific latent heat of fusion 336 kJ kg−1. After thermal equilibrium has been reached, the total mass of the water in the hollow is measured. What is the mass of the water in the hollow assuming no thermal exchange with the surroundings? A 100 g B 200 g C 260 g D 360 g 13 A system absorbs 80 J through heating while doing 100 J of external work. What is the change in internal energy of the system? A –100 J B –20 J C +80 J D +180 J insulated container

7 [Turn over 14 A mass attached to a spring is undergoing simple harmonic oscillations vertically. Interchange between kinetic energy (ke), gravitational potential energy (gpe) and elastic potential energy (epe) takes place. Which graph shows the interchange of the energy? A B A C D C <<insert image>> <<insert image>>

8 15 A mass, suspended from a helical spring, is made to oscillate. The graph shows the variation with frequency f of the amplitude x0 of vibration of the mass. A sheet of cardboard of negligible mass is now fixed to the mass on the spring to cause light damping of the oscillations. Which graph shows how x0 will vary with f over the same frequency range? The dotted line represent the original curve. A B A C D C <<insert image>> <<insert image>>

9 [Turn over 16 A plane-polarised electromagnetic wave is incident on a polarising filter as shown below. The electric field of the wave before reaching the filter is vertical and the magnitude E of the field is 𝐸 = 𝐸0 𝑠𝑖𝑛 𝑠𝑖𝑛 (𝜔𝑡) . where 𝐸0 is the amplitude and t is the time. The plane of polarisation of the filter is at 𝜃 from the vertical. What is the amplitude of the electric field emerging from the filter? A 𝐸0 2 cos2 𝜃 B 𝐸0 cos 𝜃 C 𝐸0 sin 𝜃 D 𝐸0 2 sin2 𝜃

10 17 The diagram shows a water wave in a shallow tank. The wave is diffracted though a gap in a barrier and spreads. The wavelength of the wave is much smaller than the width of the gap. The wavelength of the wave and the width of the gap are both changed by a small amount. Which combination of changes must increase the amount of spreading due to diffraction? wavelength width of gap A decreases decreases B decreases increases C increases decreases D increases increases 18 Light of wavelength 567 nm is incident normally on a diffraction grating. The grating has 400 lines per mm. What is the angle between the second-order and the third-order maxima? A 13.1 ° B 13.9 ° C 15.9 ° D 27.0 ° 19 Two point charges are separated by a distance of 200 mm. The force of attraction between them is 180 𝜇N. The distance between the point charges is increased to 600 mm. What is the new force of attraction? A 20 𝜇N B 45 𝜇N C 60 𝜇N D 90 𝜇N 20 An alpha particle is m