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 resistanc