Prelim (H2) P2 2021_QP and Solutions

1 Class Index Number Name 20S ST. ANDREW’S JUNIOR COLLEGE JC 2 2021 Preliminary Examination PHYSICS, Higher 2 9749/02 Paper 2 Structured Questions 13th September 2021 2 hours Candidates answer on the Question Paper. No additional materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and Civics Group on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Answer all questions. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 7 2 / 10 3 / 8 4 / 6 5 / 13 6 / 8 7 / 6 8 / 22 Total / 80 This document consists of 25 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 in the spaces provided. 1 Experimental measurements of the gravitational constant G in different years are shown in the table. (a) State the year in which the measurement of G appears to be the most precise. Explain your answer. …………………