TMJC MYE 2024 Section A solutions

CANDIDATE NAME ( ) CIVICS GROUP _________________________________________________________________________ H2 PHYSICS 9749 28 June 2024 30 minutes Additional Materials: Multiple Choice Answer Sheet _________________________________________________________________________ Section A: Multiple Choice Question Booklet READ THESE INSTRUCTIONS FIRST You do not need to submit this Booklet at the end of the examination. Write in soft pencil. Do not use paper clips, glue or correction fluid. Write your name, class and index number on the Multiple Choice Answer Sheet in the spaces provided. There are fifteen questions on this paper. Answer all questions. For each question there are four possible answers A, B, C, D. Choose the one you consider correct and record your choice in soft pencil on the Multiple Choice Answer Sheet. Read the instructions on the 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 in this booklet. The use of an approved scientific calculator is expected, where appropriate. You are to spend 30 minutes on Section A. This document consists of 11 printed pages and 1 blank page. TAMPINES MERIDIAN JUNIOR COLLEGE JC2 MID-YEAR EXAMINATION

2 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics Data speed of light in free space c = permeability of free space o = permittivity of free space ε0 = = elementary charge e = the Planck constant h = unified atomic mass constant u = rest mass of electron me = rest mass of proton mp = molar gas constant R = 8.31 J K−1 mol−1 the Avogadro constant NA = the Boltzmann constant k = gravitational constant G = acceleration of free fall g = 813.00 10 m s − 714 10 H m −− 12 18.85 10 F m−− ( )( ) 911/ 36 10 F m −− 191.60 10 C− 346.63 10 J s− 271.66 10 kg− 319.11 10 kg− 271.67 10 kg− 23 16.02 10 mol − 23 11.38 10 J K−− 11 2 26.67 10 N m kg−− 29.81 m s−

3 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics Formulae uniformly accelerated motion s = ut + at2 v2 = u2 + 2as work done on / by a gas W = pV hydrostatic pressure p = gh gravitational potential  = temperature T /K = T /°C + 273.15 pressure of an ideal gas p = mean translational kinetic energy of an ideal gas molecule E = kT displacement of particle in s.h.m. x = xo sin t velocity of particle in s.h.m. v = vo cos t =   electric current I = Anvq resistors in series R = … resistors in parallel = … electric potential V = alternating current / voltage X = xo sin t magnetic flux density due to a long straight wire B = magnetic flux density due to a flat circular coil B = magnetic flux density due to a long solenoid B = radioactive decay x = decay constant = 1 2 GM r− 21 3 Nm c V 3 2 22 oxx − 12RR++ 1 / R 121/ 1/RR++ 04 Q r 0 2 d   I 0 2 N r  I 0n I ( )0 expxt −  1 2 ln2 t

4 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics Section A: Multiple Choice Questions 1 The diagram shows gravitational equipotential lines of a region in space. The gravitational potential of each line is indicated in MJ kg−1. A point mass m is placed as shown and is then released. What is the direction of motion of the point mass and the change in its acceleration as it moves? direction of motion acceleration A to the right increasing B to the right decreasing C to the left increasing D to the left decreasing Q1 Ans: C The gravitational potential becomes more negative towards the left. This means that the gravitational force is pointing towards the left. If an object is released at the point shown, it will move towards the left due to the gravitational force. The spacing between the equipotentials is becoming closer towards the left. This means that the gravitational field strength is increasing towards the left. Since the acceleration due to gravity is equal to the gravitational field strength, the acceleration is increasing as the object moves further left. −10 − 8 − 6 − 4 − 2 m

5 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 2 When a beam of white light is shone onto a diffraction grating, only 3 orders of the entire visible spectrum (400 nm to 700 nm) are observed on the screen. What is the number of lines per metre of the diffraction grating? A 100 000 lines B 400 000 lines C 500 000 lines D 800 000 lines Q2 Ans: B ( )( ) 9 3, sin 1 , where is number of lines per m 11sin 1 476190 3 700 10 n d n dN N N n    − == =    =  

6 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 3 Interference fringes are produced by the Young’s double slit experiment using monochromatic light. Which one of the following graphs correctly shows the relationship between fringe spacing x and slit separation a? A B C D Q3 Ans: B Since x =  D/ a x  1/ a 0 a 0 a x 0 a 0 a x x x

7 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 4 A solid X is in thermal equilibrium with a solid Y, which is at the same temperature as a third solid Z. The three bodies are of different materials and masses. Which one of the following statements is certainly correct? A X and Y have the same heat capacity. B Y and Z have the same internal energy. C There is no net transfer of energy if X is placed in thermal contact with Z. D It is not necessary that Y should be in thermal equilibrium with Z. Q4 Ans: C X is in thermal equilibrium with Y  X and Y same temperature Y and Z same temperature, so X, Y and Z are all same temperature So there will be no net heat flow if X is placed in thermal contact with Z.

8 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 5 Two vessels X and Y, of volumes Vx and Vy are kept at temperatures Tx and Ty. They are filled with the same ideal gas and are connected by a narrow tube. What is the ratio amount of gas in X amount of gas in Y ? A XX YY TV TV B XY YX TV TV C YY XX TV TV D YX XY TV TV Q5 Ans: D The gases are connected by a narrow tube  they have the same pressure pV nRT=  n  V T so X X X Y X YY X Y Y V n T T V Vn T V T ==

9 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 6 The circuit shows three resistors, each of resistance R, connected to a battery of constant electromotive force (e.m.f.) E with negligible internal resistance. What happens to the electric potential at P and at Q when the switch S is closed? potential at P potential at Q A unchanged unchanged B increases increases C increases decreases D decreases decreases Q6 Ans: D When switch S is closed, R1 and R2 become a parallel arrangement. Thus, p.d. across R1 and R2 decreases while p.d. across R3 increase since e.m.f. remains the same. As the potential at the earthed junction is zero, the potential at P becomes less positive, hence decrease while the potential at Q becomes more negative (hence, decrease). S Q P R R R E S Q P R2 R1 R3 E

10 Tampines Meridian Junior College 2024 JC2 Mid-Year Examination H2 Physics 7 Batteries that have the same electromotive force (e.m.f.) E but different internal resistances are used to power two lamps, either connected in series or parallel. Which circuit gives the highest brightness for each lamp? A B C D Q7 Ans: A The potential difference across and power of each lamp are calculated: Circuit A Vlamp = 0.50 E, P = V2 / R = 0.13 E2 Circuit B Vlamp = 0.29 E, P = V2 / R = 0.041 E2 Circuit C Vlamp