RI 2021 Y6 H2 Phy T3 CT QP A (1)

© Raffles Institution [Turn over RAFFLES INSTITUTION 2021 YEAR 6 JULY COMMON TEST 29 June 2021 Time: 2 hr 30 min H2 PHYSICS RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION Section A INSTRUCTIONS TO CANDIDATES There are 2 sections in this paper. Section A consists of 20 multiple-choice 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 Optical Mark Sheet. You are advised to attempt Section A first . The Optical Mark Sheets will be collected after the first 40 minutes. Section B consists of 6 structured questions and 1 data analysis question . You are to write your answers in the spaces provided. Attempt ALL questions in Sections A and B. There are 10 printed pages, inclusive of the cover page and data & formulae page, in this booklet.

2 © Raffles Institution Data speed of light in free space c = 3.00 × 108 m s−1 permeability of free space 0µ = 4π × 10−7 H m−1 permittivity of free space 0ε = 8.85 × 10−12 F m−1 = (1/(36π)) × 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 = 21 2ut at+ 2v = 2 2u as+ work done on/by a gas W = pV∆ hydrostatic pressure p = ρgh gravitational potential φ = Gm r− temperature T/K = / C 273.15T °+ pressure of an ideal gas p = 21 3 Nm cV mean translational kinetic energy of an ideal gas molecule E = 3 2 kT displacement of particle in s.h.m. x = 0 sinxt ω velocity of particle in s.h.m. v = 0 cosvt ω 22 0xxω= ±− electric current I = Anvq resistors in series R = 12 RR++  resistors in parallel 1/R = 1211 RR++  electric potential V = 4 Q rε0π alternating current/voltage x = 0 sinxt ω magnetic flux density due to a long straight wire B = 0 2 d µ π I magnetic flux density due to a flat circular coil B = 0 2 N r µ I magnetic flux density due to a long solenoid B = 0nµ I radioactive decay x = ( )0 expxt λ− decay constant λ = 12ln2 t

3 © Raffles Institution [Turn over 1 The following statements concern two systems in thermal contact with each other. Which of them is not equivalent to the rest? A The two systems are at the same temperature. B The two systems are in thermal equilibrium with each other. C The molecules of the two systems have the same mean speed. D The molecules of the two systems have the same mean kinetic energy. 2 A heat-insulating container is divided into two compartments, of volumes 0.30 m3 and 0.50 m3, by a fixed wall that is permeable to heat , as shown in the diagram below. The left and right compartments are filled with 2.0 mol and 3.0 mol of ideal gases, respectively. At equilibrium, what is the ratio of the pressure in the left compartment to that in the right compartment? A 0.40 B 0.90 C 1.1 D 2.5 3 An ideal gas of fixed quantity can undergo the three different processes 1, 2 and 3 as shown in the figure below. The dotted lines are isotherms of temperatures T1 and T2. Which process(es) can be adiabatic? A 1, 2 and 3 B 2 and 3 C 2 only D 3 only P V T1 T2 1 2 3 T1 T2 heat-insulating wall fixed wall permeable to heat V1 = 0.30 m3 n1 = 2.0 mol V2 = 0.50 m3 n2 = 3.0 mol

4 © Raffles Institution 4 Which of the following statements is true? A For a system of fixed mass, an increase in temperature is always accompanied by an increase in internal energy. B For a system of fixed mass, an increase in internal energy is always accompanied by an increase in temperature. C A system at a higher temperature must have more internal energy than another system at a lower temperature. D A system with more internal energy must be at a higher temperature than another system with less internal energy. 5 X and Y are two small identical conducting spheres with their centres separated by a distance d. X has a charge +6.0 μC and Y has a charge –2.0 μC. Both spheres experience an electric force of magnitude F towards each other. The spheres are brought into contact and then separated to a distance 2 d . Which of the following correctly describes the electric force acting on each of the spheres after they are separated to a distance 2 d ? magnitude direction A 2 3 F attractive B 2 3 F repulsive C 4 3 F attractive D 4 3 F repulsive

5 © Raffles Institution [Turn over 6 The diagram shows two large horizontal metal plates situated 30 mm apart. The top and bottom plates are at potentials −50 V and −10 V respectively. Point X is midway between the metal plates and point Y is a distance 20 mm from X as shown. What is the work done by the electric f orce when a charge of −5.0 µC is moved from point X to point Y? A −1.3 × 10−4 J B −8.0 × 10−5 J C 8.0 × 10−5 J D 1.3 × 10−4 J 7 The diagram shows four point charges of different magnitudes placed at the corners of a square of length 1.0 m. X lies at the geometrical centre of the square. What is the resultant electric potential at X? A −7.2 × 1010 Q B −5.0 × 1010 Q C −2.5 × 1010 Q D 1.3 × 1011 Q 8 A copper wire of diameter 2.1 mm carries a current of 20 A. The drift velocity of the electrons in the wire is 4.5 × 10−4 m s−1. What is the number of electrons per unit volume of the wire? A 1.3 × 1010 m−3 B 1.3 × 1026 m−3 C 6.3 × 1028 m−3 D 8.0 × 1028 m−3 −50 V −10 V 12 mm 20 mm 16 mm X Y 30 mm 1.0 m 1.0 m X −4Q −3Q +2Q +Q

6 © Raffles Institution 9 A cell of internal resistance r is connected to a load of resistance R. Which statement is correct when switch S is closed? A The e.m.f. of the battery decreases because there is work done in driving charges through the internal resistance r of the battery. B The e.m.f. of the battery decreases because there is work done in driving charges through the resistance R. C The potential difference across the battery decreases because there is work done in driving charges through the internal resistance r of the battery. D The potential difference across the battery decreases because there is work done in driving charges through the resistance R. 10 The graph shows the current-voltage (I-V) characteristics of a thermistor. Which of the following statements explains the shape of the graph? A As the temperature increases, the charge carriers collide with the atomic lattice more often and moves faster. B As the temperature increase s, there is a significant increase in the number of charge carriers. C As the