HCI 2022 Prelim P3 (Section B)

This document consists of 11 printed pages. HWA CHONG INSTITUTION JC2 Preliminary Examination Higher 2 CANDIDATE NAME CT GROUP 21S CENTRE NUMBER INDEX NUMBER PHYSICS Paper 3 Longer Structured Questions SECTION B BOOKLET Candidates answer on the Question Paper. No Additional Materials are required. 9749/03 15 September 2022 2 hours INSTRUCTIONS TO CANDIDATES Write your Centre number, index number, name and CT class clearly on all work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paperclips, highlighters, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer one question only. Circle the question number on the cover page. You are advised to spend one and a half hours on Section A and half an hour on Section B. The number of marks is given in brackets [ ] at the end of each question or part question. You are reminded of the need for good English and clear presentation in your answers. For Examiner’s Use SECTION B (circle 1 question) 8 20 9 20 Deductions

2 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 Data Formulae speed of light in free space, c = 3.00  10 8 m s −1 permeability of free space, 0 = 4  10 −7 H m −1 permittivity of free space, 0 = 8.85  10 −12 F m −1  (1/(36))  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  10 23 mol −1 the Boltzmann constant, k = 1.38  10 −23 J K −1 gravitational constant, G = 6.67  10 −11 N m 2 kg −2 acceleration of free fall, g = 9.81 m s −2 uniformly accelerated motion work done on / by a gas hydrostatic pressure gravitational potential temperature pressure of an ideal gas mean translational kinetic energy of an ideal gas molecule displacement of particle in s.h.m. velocity of particle in s.h.m. electric current resistors in series resistors in parallel electric potential alternating current / voltage magnetic flux density due to a long straight wire magnetic flux density due to a flat circular coil magnetic flux density due to a long solenoid radioactive decay decay constant s = ut + 2 1 at2 v 2 = u 2 + 2as W = p V p = gh  = − Gm r T/K = T/C + 273.15 p = 21 3 Nm cV  kTE 2 3= x = x0sint v = v0cost = 22 0()xx− I = Anvq R = R1 + R2 + . . . 1/R = 1/R1 + 1/R2 + . . . V = Q 40r x = x0sint B = 0I 2d B = 0NI 2r B = 0nI x = x0 exp(−t )  = ln 2 t 1 2

3 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 Section B Answer one question from this Section in the space provided. 8 (a) (i) State the principle of superposition. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………..…………………………. [2] (ii) When two waves superpose, state three conditions necessary for a stable and observable interference pattern. 1. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… 2. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… 3. ………………………………………………………………………………………………… ………………………………………………………………………………………………… ………………………………………………………………………………………………… [3]

4 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 (b) Two coherent transverse wave sources produce wavefronts as shown in Fig. 8.1. The sources S1 and S2 are 3.0 mm apart. The line CC is parallel to the line joining S 1 and S2 and it is 1.00 m away from the sources. Fig. 8.1 is not drawn to scale. Fig. 8.1 (not to scale) Lines where the amplitude of the resultant wave is minimum is known as a nodal line. Lines where the amplitude of the resultant wave is a maximum is known as an antinodal line. (i) Line MM is a nodal line. Hence, deduce the phase difference (in degrees) between the sources S1 and S2. phase difference = …………………… o [1] (ii) On Fig. 8.1, draw a line where the path difference in terms of wavelength λ of the waves from the two sources is 1. 2 λ. Label this line EE. [1] 2. 0.5 λ. Label this line FF. [1] (iii) State whether the line FF is a nodal or antinodal line. Line FF: …………………………………………………………..………… [1] S1 3.0 mm S2 1.00 m C C M M

5 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 (iv) Identify the particular interference pattern detected along line S1S2. .……………………………………………………………………………………………… [1] (v) Show that the wavelength of the waves generated by the two sources is 0.5 mm. [1] (vi) Along line S 1S2 , determine the number of minimas (locations where the resultant wave has the smallest amplitude) detected between the two sources. Ignore what is detected at the sources. number of minimas = …………………….. [3] (vii) Determine the distance between each maxima that can be detected along line CC. distance between each maxima = …………………….. m [2]

6 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 (viii) Describe how the new interference pattern detected along lines CC and S 1S2 compares with the old pattern when the following changes are made separately. 1. The distance between S1 and S2 is increased. CC: ………………………………………………………………………………………….. ………………………………………………………………………………………………… ………………………………………………………………………………………………… S1S2: …………………………………………………………………………………………. ………………………………………………………………………………………………… ………………………………………………………………………………………………… [2] 2. The amplitude of waves from S1 is smaller than the waves from S2. CC: …………………………………………………………………………………………... ………………………………………………………………………………………………… ………………………………………………………………………………………………… S1S2: …………………………………………………………………………………………. ………………………………………………………………………………………………… ………………………………………………………………………………………………… [2] [Total: 20]

7 © Hwa Chong Institution 9749 / 03B / C2 Preliminary Examinations 2022 9 (a) State Coulomb’s Law. ………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………. ………………….…………………………………………………………..…………………………. [1] (b) In a simple model of the structure of an atom, a hydrogen atom can be thought of as consisting of an electron in circular orbit around a proton, as shown in Fig. 9.1.