SAJC Prelim (H2) P1 2023

1 SAJC 2023 Preliminary Examination / 9749 [Turn Over Class Index Number Name 22S ST. ANDREW’S JUNIOR COLLEGE JC 2 2023 Preliminary Examination PHYSICS, Higher 2 9749/01 Paper 1 Multiple Choice 18th September 2023 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.

2 SAJC 2023 Preliminary Examination / 9749 [Turn Over Data speed of light in free space c = 3.00 x 108 m s-1 permeability of free space o = 4  x 10-7 H m-1 permittivity of free space o = 8.85 x 10-12 F m-1 = (1/(36)) 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 V hydrostatic pressure p =  g h gravitational potential  = r Gm− 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 = 2 3 kT displacement of particle in s.h.m. x = xo sin  t velocity of particle in s.h.m. v = v0 cos  t v =   22 0 xx − electric current I = Anvq resistors in series R = R1 + R2 + ... resistors in parallel 1 / R = 1 / R1 + 1 / R2 + ... electric potential V = r Q 04 alternating current/voltage x = xo sin  t magnetic flux density due to a long straight wire B = μ0I 2πd magnetic flux density due to a flat circular coil B = μ0NI 2r magnetic flux density due to a long solenoid B = μ0nI radioactive decay x = xo exp (- t) decay constant  = 2/1 2ln t

3 SAJC 2023 Preliminary Examination / 9749 [Turn Over Answer all questions. 1 Planck’s Law of black body radiation is given by ( ) 1 12 2 3 − =      kT hf e c DhR where R is power per unit area per unit frequency, h is Planck’s constant, c is the speed of light in a vacuum, f is frequency of electromagnetic radiation, k is Boltzmann’s constant, T is the thermodynamic temperature, and D is an unknown physical quantity. Which of the following shows the correct units for D? A kg m s-2 B s-1 C kg m2 s-2 D s-3 2 The momentum p of a rubber ball of mass m, as it rolls across a table surface at constant speed is given by the equation p = mL t2 - t1 , where t1 is the time at which the front end of the ball passes point P, t2 is the time at which the front end of the ball passes point Q. Data from an experiment to determine p is recorded as follows: m = (52.000 ± 0.001) g L = (10.0 ± 0.1) cm t1 = (0.00 ± 0.01) s t2 = (0.63 ± 0.01) s The momentum of the rubber ball should be recorded as A (830 ± 20) g cm s-1 B (830 ± 30) g cm s-1 C (825 ± 28) g cm s-1 D (825 ± 35) g cm s-1 L P Q

4 SAJC 2023 Preliminary Examination / 9749 [Turn Over 3 A ball moves along a straight line. The variation of its displacement x with time t is given by the graph. At which point is the acceleration of the ball the greatest? 4 A cannon ball is fired at a speed of 450 m s-1 at sea level at an angle of θ = 31.6o with respect to horizontal. The cannon ball hits the top of a watchtower located 900 m away. How high is the top of the watchtower above sea level? Neglect air resistance. A 526 m B 542 m C 580 m D 1390 m

5 SAJC 2023 Preliminary Examination / 9749 [Turn Over 5 A resultant force F acts on a mass m. The variation with time t of F is as shown. Mass m is 150 g. At time t = 0, the mass is at rest. Which of the following statements is incorrect? A The mass slowed down at a decreasing rate from t = 0.25 s to t = 0.50 s. B The mass is momentarily at rest at t = 0.50 s. C The mass reversed direction at t = 0.50 s and sped up at a decreasing acceleration from t = 0.50 s to t = 0.75 s. D The magnitude of the change in velocity of the mass from t = 0.25 s to t = 0.75 s is 0.53 m s-1.

6 SAJC 2023 Preliminary Examination / 9749 [Turn Over 6 A 1.200 m light beam carries a mass M at one end. A light cord affixed to the wall is supporting the beam at 0.805 m from the wall as shown. What is the maximum mass M that can be supported if the maximum allowed tension in the cord is 300 N? A 10.3 kg B 17.8 kg C 20.5 kg D 101 kg 7 A helium balloon of volume V carrying a light weather instrument rises into the atmosphere. The total mass of the balloon skin and the weather instrument is M kg. Given the gravitational field strength is g, the density of air is ρair, and the density of helium is ρHe, the net force acting on the balloon is A (ρair - ρHe)Vg B (ρair)Vg – Mg C (ρair - ρHe)Vg – Mg D (ρHe - ρair)Vg - Mg 30 M 0.805 m 1.200 m light cord wall light beam

7 SAJC 2023 Preliminary Examination / 9749 [Turn Over 8 A metal wire is stretched by a varying force F, causing its extension x to increase as shown by the line OPQ on the graph. The force is then gradually reduced to zero and the relation between force and extension is indicated by line QR. Which of the following correctly represents the work done by the force F in stretching the wire to Q and the corresponding elastic potential energy stored in the wire Work done by the force F in stretching the wire to Q Elastic potential energy stored in the wire A Y+X X B Y Z C Y+Z Z D Y+Z Y+Z 9 A car moves with the same speed over each of the 4 bridges shown below. In which option is the force which the car exerts on the midpoint of the bridge the smallest?

8 SAJC 2023 Preliminary Examination / 9749 [Turn Over 10 An isolated spherical planet has mass M and radius R. The acceleration of free fall on the surface of the planet is g. What is the work done to move a small mass m from the surface to a height 2 R above the surface? A 0.50 mgR B 0.67 mgR C mgR D 2.0 mgR 11 The temperature of 1 kg of Hydrogen gas is the same as that of 1 kg of Helium gas if A the gases have the same internal energy B the gas occupy equal volumes C the gas molecules have the same root mean square speed D the gas molecules have the same mean translational kinetic energy 12 A 40 W filament lamp has been operating normally for some time so that its temperature is stable. Which of the following shows the correct quantities with respect to the filament? rate of heating the filament / W rate of doing work on filament / W A - 40 +40 B 0 +40 C +40 0 D +40 -40 13 A small mass executes s.h.m. about a point O with amplitude a and period T. Its displacement from O at time T/8 after passing through O is A 8 a B 22 a C 2 a D 2 a

9 SAJC 2023 Preliminary Examination / 9749 [Turn Over 14 Fig. 14.1 shows the variation with displacement x of velocity v of a simple harmonic oscillator. Fig. 14.2 shows the