2021 H2 Phy Prelim Paper 1 Question Paper (forJCs)

©YIJC [Turn over 2021 YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO PHYSICS Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet 9749/01 17 September 2021 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. Write your name and class 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. This document consists of 16 printed pages.

2 ©YIJC [Turn over Data speed of light in free space, c = 3.00  108 m s–1 permeability of free space, o = 4  10–7 H m–1 permittivity of free space, o = 8.85  10–12 F m–1 (1/(36))  10–9 F m–1 elementary charge, e = 1.60  10–19 C the Planck constant, h = 6.63  10–34 J s unified atomic mass constant, u = 1.66  10–27 kg rest mass of electron, me = 9.11  10–31 kg rest mass of proton, mp = 1.67  10–27 kg molar gas constant, R = 8.31 J K–1 mol–1 the Avogadro constant, NA = 6.02  1023 mol–1 the Boltzmann constant, k = 1.38  10–23 J K–1 gravitational constant, G = 6.67  10–11 N m2 kg–2 acceleration of free fall, g = 9.81 m s–2 Formulae uniformly accelerated motion, s = ut + 2 1 at2 v2 = u2 + 2as work done on/by a gas, W = p  V hydrostatic pressure, p =  g h gravitational potential,  = r Gm temperature, T/K = T/°C + 273.15 pressure of an ideal gas, p = 2CV Nm 3 1 mean translational kinetic energy of an ideal gas molecule, E = kT2 3 displacement of particle in s.h.m. x = xo sin  t velocity of particle in s.h.m., v = vo cos  t =   )( 22 xxo  electric current, I = A n v q resistors in series, R = R1 + R2+………. resistors in parallel, R 1 = ........11 21  RR electric potential, V = r Q o4 alternating current/voltage, x = xo sin  t magnetic flux density due to a long straight wire, B = dπ2 o Iμ magnetic flux density due to a flat circular coil, B = r2 No Iμ magnetic flux density due to a long solenoid, B = Ion radioactive decay, x = xo exp(–t)

3 ©YIJC [Turn over decay constant,  = 2 1t 2 ln 1 The radiancy, RT, is defined as the total energy emitted per unit time per unit area from a blackbody at thermodynamic temperature T. It was first stated empirically in 1879 in the form given by RT = σT4 where where σ is called the Stefan-Boltzmann constant. Which of the following is the unit for σ? A W m2 K4 B kg s3 K4 C J s m2 K4 D J s1 m2 K4 2 A student measures the current through an ohmic conductor and the potential difference (p.d.) across it at a constant temperature. The measurements are then used to plot a graph of current against p.d. There is a systematic error in the current measurements. How could the systematic error be identified from the graph? A The data points have a large scatter. B The graph is a curve instead of a straight line. C The line of best fit does not pass through the origin. D At least one anomalous data point can be identified. 3 A car is travelling at close to the top speed on a Singapore expressway. The driver sees a large obstacle on the road and brings the car to a complete stop. Which value is the best estimate of the car’s change in momentum? A 2  102 kg m s1 B 2  104 kg m s1 C 2  106 kg m s1 D 2  108 kg m s1

4 ©YIJC [Turn over 4 When a bottle of fizzy drink is poured into a tall glass, gas bubbles are seen forming and rising to the surface. The dots in the diagram represent the gas bubbles. The time interval between successive dots is equal. Assuming that there is no change in volume of the gas bubbles, which of the following options shows the path of the bubbles? 5 A student throws a ball vertically upwards. Upward velocities are taken as positive. The ball makes an elastic collision with the ceiling, rebounds and accelerates back to the student’s hand in a time of 1.2 s. Which graph best represents the acceleration of the ball from the moment it leaves the hand to the instant just before it returns to the hand? A B C D A B C D

5 ©YIJC [Turn over 6 A block with a pendulum bob hanging inside lies on a rough horizontal surface. The total mass of the block and the pendulum bob is 100 kg. A force of 250 N is applied to the block and the pendulum bob makes an angle of 11.0° to the vertical axis. What is the magnitude of the frictional force acting on the block? A 28 N B 42 N C 59 N D 94 N 7 The variation of the force F with time t acting on a body of mass 200 g is as shown in the graph below. Given that the velocity of the body at t = 75 ms is 15 m s 1, what is the velocity of the body at t = 150 ms? A 7.8 m s1 B 30 m s1 C 39 m s1 D 55 m s1 11.0 250 N Block with pendulum bob inside F / N t / ms

6 ©YIJC [Turn over 8 Two blocks X and Y of masses m and 2m respectively are accelerated along a smooth horizontal surface by forces 2F and F applied to blocks X and Y respectively as shown. Which diagram does not correctly show the resultant force acting on the block(s)? A B C D 9 Three coplanar forces act on a block. Which diagram shows the directions of the forces such that the block could be in equilibrium? A B C D X Y 2F F X Y F Y X X

7 ©YIJC [Turn over 10 A steel sphere is dropped from rest vertically onto a horizontal metal plate. The sphere hits the plate with speed u, leaves it at speed v, and rebounds vertically to half of its original height. Ignore effects of air resistance. Which expression gives the value of v u ? A 2 1 2 B 1 2 C 1 2 D 11 2  11 A car of mass 500 kg is at rest at point X on a slope, as shown. The car’s brakes are released and the car rolls down the slope with its engine switched off. At point Y, the car has moved through a vertical height of 30 m and has a speed of 11 m s1. What is the energy dissipated by frictional forces when the car moves from X to Y? A 3.0  104 J B 1.2  105 J C 1.5  105 J D 1.8  105 J 12 A stone at the end of a string is whirled in a vertical circle at a constant speed. Which of the following statements is correct? A The tension in the string stays constant. B The tension is least when the stone reaches the bottom of the circle. C The weight of the stone is always the centripetal force. D The tension is greatest when the stone is at the bottom of the circle.

8 ©YIJC [Turn over 13 Two point masses, each of 8000 kg are placed 0.25 m apart at points X and Y as shown in the figure below. Points XYP form an equilateral triangle. What is the gravitational potential energy of a mass of 5.0 kg placed at point P? A  1.1  105 J B  2.1  105 J C  4.3  105 J D  8.5  105 J 14 Two iron spheres of different radii are in thermal contact in a vacuum as shown. The sphere