Pure Physics Nov 2022_TYS ANSWERS

Nov 2022_Suggested ANSWERS_as at June 2023 Page 1 of 9 – Nov 2021 Catholic High School | O-Level Physics NOT IN SYLLABUS: 6091 Nov 2022 P1: - Suggested Answers P2: - Paper 1 [40 marks] 1 A 11 B 21 B 31 B 2 D 12 B 22 A 32 B 3 C 13 D 23 C 33 C 4 C 14 D 24 A 34 A 5 B 15 D 25 D 35 A 6 D 16 C 26 C 36 B 7 C 17 D 27 A 37 D 8 D 18 A 28 C 38 A 9 B 19 C 29 A 39 C 10 C 20 D 30 B 40 A *Q. 2: D Students who selected C related an acceleration to a change in speed rather than to a change in velocity. *Q. 9: B Students who selected A were able to understand that Y is larger than X and Z due to Newton’s First Law. However, they erroneously thought that the magnitudes of the two forces X and Z are directly proportional to their distances from the centre of gravity. This could be due to them trying to answer using proportions rather than considering the Principle of Moments equation. *Q. 14: D Students who selected A did not consider that the temperature of the vapour and the liquid water are equal, and the effect of temperature on the molecular kinetic energies. *Q. 17: D This question is challenging, with most students selecting C which suggested that the athlete would cool down more quickly rather than more slowly. They may have learnt that shiny surfaces are poor emitters and poor absorbers of infra-red radiation but cou ld not automatically relate this to the reflection properties. Students who selected A or B did not consider it plausible that a shiny surface could result in less radiation being reflected. *Q. 19: C Students commonly selected A. It is important to read the question carefully to distinguish between total internal energy and average internal energy. *Q. 21: B Students who selected D are unable to see the inverse relation between period and frequency based on the formula. They may also not have considered the fact that the straight line shown could have been extrapolated to negative periods or frequencies which, in the context of wave motion, are meaningless concepts.

Nov 2022_Suggested ANSWERS_as at June 2023 Page 2 of 9 – Nov 2021 *Q. 30: B Students who selected C suggested that the filament lamp has a constant resistance, which is incorrect as the lam p is an ohmic conductor with a resistance that increase with voltage/current. *Q. 34: A Students who selected the wrong options may have failed to realise that resistance of (and hence p.d. across) the thermistor (or LDR) decreases when temperature (or light intensity) increases. *Q. 36: B Students who selected A or D ay have confused the magnetic fi eld with an electric field. Students who selected C may not have understood correctly that the direction of (conventional) current used in Fleming’s Left Hand Rule is the same as the direction of movement of positive charges and opposite to the direction of movement of negative charges. *Q. 40: A Students who selected B or D ignored the reduction in