Pure Physics Nov 2018_TYS ANSWERS

Nov 2018_Suggested ANSWERS_as at July 2023 Page 1 of 8 – Nov 2018 Catholic High School | O-Level Physics NOT IN SYLLABUS: 6091 Nov 2018 P1: - Suggested Answers P2: - Paper 1 [40 marks] 1 B 11 A 21 D 31 A 2 D 12 B 22 B 32 A 3 C 13 D 23 C 33 A 4 C 14 C 24 B 34 A 5 C 15 C 25 D 35 D 6 B 16 D 26 B 36 C 7 A 17 A 27 B 37 D 8 C 18 A 28 D 38 B 9 A 19 B 29 B 39 B 10 A 20 D 30 C 40 C *Q. 9: A This question tested the way in which the gravitational fields of the Earth and the Moon interact. It is a commonly held, but erroneous view that beyond the Earth’s atmosphere, objects no longer experience a gravitational force due to the Earth. (B is incorrect.) *Q. 12: B Both of the forces referred to in the question are one force of a Newton’s third law pair and it is necessary to be clear which of the two forces, in each case, is the one being asked for. Confusion with this led to the selection of any of the three incorrect options. *Q. 15: C The question concerns the energy transfer that is taking place as the stone slows down as it moves downwards in the water. Both the kinetic energy and the gravitational potential energy are decreasing during this time. (A and B are incorrect.) *Q. 21: D Convection in air can only transfer heat upwards. Consequently, the options that include convection could not be correct. The question states that the temperature of the air is greater than that of the ice and so there will also be some transfer of heat by radiation. Thermal radiation from gases must be considered. *Q. 30: C It is commonly understood that the resistance of the circuit decreased, and deduced from this that the current supplied by the cell and hence the current in the lamp, increased – thus an increased potential difference across the lamp was often successfully chosen. As there are two significant potential differences in the circuit – one increases whilst the other decreases – it is easy to be confused. (A is incorrect.)

Nov 2018_Suggested ANSWERS_as at July 2023 Page 2 of 8 – Nov 2018 *Q. 32: A This question tested both factual knowledge and one consequence of the fact. Most are aware that a voltmeter measures the potential difference between the two terminals of the component with which it is connected in parallel. The question makes clear that the voltmeter does not affect the current and it is wrong to interpret this to mean that the resistance of the voltmeter had to be small. (B is incorrect.) *Q. 33: A (B and C are incorrect.)

Nov 2018_Suggested ANSWERS_as at July 2023 Page 3 of 8 – Nov 2018 Paper 2 [80 marks] 1 ai The value on the main scale is 7.50 mm, and should be added to 0.48 mm on the rotating scale. 1 1 aii Action: Close the jaws of the micrometer completely. Reason: To check for and subtract away the zero error. OR: Action: Take average of diameters at different positions along cylinder. Reason: The cylinder may not be uniformly shaped. [Note: