Pure Physics Nov 2021_TYS ANSWERS

Nov 2021_Suggested ANSWERS_as at July 2023 Page 1 of 6 – Nov 2021 Catholic High School | O-Level Physics NOT IN SYLLABUS: 6091 Nov 2021 P1: - Suggested Answers P2: - Paper 1 [40 marks] 1 C 11 D 21 B 31 C 2 B 12 B 22 C 32 B 3 D 13 D 23 B 33 A 4 A 14 C 24 B 34 A 5 A 15 A 25 A 35 C 6 B 16 C 26 A 36 D 7 C 17 B 27 D 37 C 8 C 18 C 28 D 38 B 9 C 19 B 29 D 39 A 10 D 20 D 30 A 40 C *Q. 1: C Students who selected B or D are unable to understand the fact that R should start from the start point of vector V and end at the end point of vector W. Students who selected A failed to realise that the wind is blowing from west to east and not from east to west. *Q. 2: B Students who struggle to know how to start should think of any formula for acceleration, and then proceed to break down the terms in the formula further based on information in the question. In this case, a = (v – u)/t, and t = distance between posts / average speed of car between posts. *Q. 11: D Students who selected C did not understand that stability is related to the position of the centre of gravity of an object. *Q. 12: B Students who selected the wrong answers were unable to convert the incompatible units in the question to standard SI units and then to convert the answer to the non -SI metric unit of N / cm 2. Students who selected A may have forgotten to factor in gravitational field strength in their calculations. *Q. 13: D Students who selected C took the area of the piston on the right to be double that of the piston on the left. *Q. 14: C Students who selected A did not use the formula P = Patm + dρg to deduce that the y-intercept of the graph is atmospheric pressure, and that P varies linearly with d. *Q. 21: B Students who selected D took the two fixed points as the two ends of the full range of the thermometer rather than the melting point of pure ice and the boiling point of pure water. *Q. 22: C Students who selected A or B did not understand that at constant temperature, the average kinetic energy of the molecules does not change. Students who

Nov 2021_Suggested ANSWERS_as at July 2023 Page 2 of 6 – Nov 2021 selected D did not understand that potential energy is related to the average intermolecular distance, and that condensation reduces this. *Q. 26: A Students who selected B failed to understand that while the incident ray is reflected in the correct direction, it does not undergo total internal reflection, unlike A. *Q. 34: C Students need to be clear that as R = V/I, J has the highest resistance as current is 0. Students who chose B or D mistakenly thought that the gradient of the current-p.d. graph is related to the magnitude of the resistance, when in fact resistance is the ratio of p.d. to cur rent, not the gradient (or the reciprocal of the gradient) of the current-p.d. graph. *Q. 35: C Students can consider using the formula I = V/R (where V is the e.m.f. of the circu