Prelim (H2) P1 2021 QP and Solutions

1 Class Index Number Name 20S ST. ANDREW’S JUNIOR COLLEGE JC 2 2021 Preliminary Examination PHYSICS, Higher 2 9749/01 Paper 1 Multiple Choice 17th September 2021 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil.. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and Civics Group the Answer Sheet in the spaces provided. There are thirty questions in 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. 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. For Examiner’s Use Total / 30 This document consists of 15 printed pages including this page. SAJC 2021 Preliminary Examination / 9749 [Turn Over

2 Data speed of light in free space c = 3.00 x 108 m s-1 permeability of free space mo = 4 p x 10-7 H m-1 permittivity of free space eo = 8.85 x 10-12 F m-1 = (1/(36p)) x 10-9 F m-1 elementary charge e = 1.60 x 10-19 C the Planck constant h = 6.63 x 10-34 J s unified atomic mass constant u = 1.66 x 10-27 kg rest mass of electron me = 9.11 x 10-31 kg rest mass of proton mp = 1.67 x 10-27 kg molar gas constant R = 8.31 J K-1 mol-1 the Avogadro constant NA = 6.02 x 1023 mol-1 the Boltzmann constant k = 1.38 x 10-23 J K-1 gravitational constant G = 6.67 x 10-11 N m2 kg-2 acceleration of free fall g = 9.81 m s-2 Formulae uniformly accelerated motion s = u t + ½ a t2 v2 = u2 + 2 a s work done on/by a gas W = p DV hydrostatic pressure p = g h gravitational potential f = −Gm r temperature T / K = T / oC + 273.15 pressure of an ideal gas p = 1 3 Nm V ⟨ c2 ⟩ mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = xo sin t velocity of particle in s.h.m. v = v0 cos w t v = ± w √ x0 2− x2 electric current I = Anvq resistors in series R = R1 + R2 + ... resistors in parallel 1 / R = 1 / R1 + 1 / R2 + ... electric potential V = Q 4 πε0 r alternating current/voltage x = xo sin  t magnetic flux density due to a long straight wire B = μ0 I 2πd magnetic flux density due to a flat circular coil B = μ0 NI 2r magnetic flux density due to a long solenoid B = μ0 n I radioactive decay x = xo exp (-l t) SAJC 2021 Preliminary Examination / 9749 [Turn Over

3 decay constant  = ln 2 t1/2 Answer all questions. 1 Using an ohm-meter, a student measures the resistance of two resistors R1 and R2 separately with their associated uncertainties shown as follows: R1 = 200 ± 5  R2 = 800 ± 5  The two resistors R1 and R2 are then connected in parallel. He calculated the effective resistance, R to be 160 . What is the uncertainty of the effective resistance? A 2.5  B 3.4  C 5  D 10  2 A train, initially at rest at a station, has a uniform acceleration of 0.20 m s –2 until it reaches a speed of 20 m s –1. It travels for some time at this constant speed and then has a uniform deceleration of 0.40 m s–2 until it comes to rest at the next station. The distance between the two stations is 3000 m. What is the time taken by the train to travel between the two stations? A 75 s B 150 s C 230 s D 300 s 3 A ball bearing is released from rest 10 cm above a tall measuring cylinder which is filled with oil. Which one of the following graphs best represents the variation with time t of displacement x of the ball bearing? SAJC 2021 Preliminary Examination / 9749 [Turn Over

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A B C Force 5 4 Two masses, M and m, are connected by an inextensible string which passes over a frictionless pulley. Mass M rests on a frictionless slope, as shown. The slope is at an angle  to the horizontal. The two masses are initially held stationary and then released. Mass M accelerates down the slope. Which expression must be correct? A sin  < m M B cos  < m M C sin  > m M D cos  > m M 5 The diagram below shows 4 identical wooden blocks connected by inelastic strings, A, B and C. A constant force accelerates the blocks to the right on a horizontal frictionless table. Which string has the greatest tension? A String A B String B C String C D All have the same tension SAJC 2021 Preliminary Examination / 9749 [Turn Over

6 6 Forces are applied to the ends of a rod so that its length increases. The variation with force F of the extension e of the rod is shown. The point P is the elastic limit. Plastic deformation occurs when the rod is extended beyond point P, causing it to be permanently distorted. Which shaded area represents the work done during the plastic deformation of the rod? SAJC 2021 Preliminary Examination / 9749 [Turn Over

40 1.2 m 7 7 A man, carrying a large rock, sits in a boat on a lake. He drops the rock into the lake. Assume the total volume of the water in the lake is constant, the water level of the lake A increases because the density of the rock is larger than water hence the upthrust acting on it would be larger for equilibrium to occur. B decreases because the density of the rock is larger than water and hence displaces a smaller volume of water as compared to when it was on the boat. C remains the same because the total mass of all the objects in the lake remains the same. D remains the same because the rock will sink to the bottom of the lake and experience a normal contact force. 8 A body of mass m undergoes uniform circular motion with speed v. Which graph represents the relationship between the force F acting on the body and v? 9 A simple pendulum of length 1.2 m is swung such that the mass goes round in a uniform circular motion in the horizontal plane. The string makes an angle of 40° with the vertical. What is the speed of the mass in its circular path? A 2.5 m s-1 B 2.8 m s-1 C 3.0 m s-1 D 3.3 m s-1 SAJC 2021 Preliminary Examination / 9749 [Turn Over v v v v

8 10 The planet Jupiter has satellites called Io and Europa which have different orbital radii and different orbital time periods. The table shows the orbital radii for Io and Europa and the orbital time period of Io. What is the orbital time period TE of Europa? A 0.88 days B 2.4 days C 2.8 days D 3.5 days 11 The gravitational potentials on the surface of a planet P and on the surface of its moon Q are 120 MJ kg1 and 20 MJ kg1 respectively. The minimum amount of energy required to project a 1 kg mass from the surface of Q to the surface of P is E. Which of the following correctly describes the value of E? A E < 20 MJ B E = 20 MJ C 20 MJ < E < 100 MJ D 100 MJ < E < 120 MJ 12 A sealed tank of gas contains a mixture of nitrogen and oxygen. The tank is at room temperature. What is the same for the particles of nitrogen and oxygen in the tank? A internal energy B mean square speed C mean kinetic energy D root mean square speed 13 The density of air is 1.20 kg m –3 at a temperature of 20 °C and standard atmospheric pressure. What is the density of air at a temperature of 27 °C and standard atmospheric pressure? A 0.89 kg m–3 B 1.17 kg m–3 C 1.23 kg m–3 D 1.62 kg m–3 SAJC 2021 Preliminary Examination / 9749 [Turn Over

9 14 An undamped oscillator is executing simple harmonic motion. A graph of the acceleration a against time t for this oscillator is shown. Which graph shows the variation of the kinetic energy E of the oscillator with time t? SAJC 2021 Preliminary Examination / 9749 [Turn Over a

P S1 S2 60° 30° 10 15 The graph shows how the amplitude of a simple pendulum decays with time from an initial amplitude of 5.0 cm. What is the fraction of the initial energy that has been lost in the first 4.0 s? A 1 16 B 1 4 C 3 4 D 15 16 16 S1 and S2 produce waves in phase of amplitude A and intensity I that are polarized