EJC 2023 J2 H2 PRELIM P4 MS

©EJC 2023 9749/04/J2H2Prelim/2023 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2023 9749 PHYSICS MARK SCHEME Paper 4 – Practical Qns Answer Marks 1aiii • Maximum reading for w is 6.5 cm • Correct precision of 0.1 cm and corresponding unit • Repeated readings 1 1bii • No. of oscillations stated clearly • Measured time precise to 0.01 s with correct unit Duration > 10s • Repeated readings 1 • Period calculated to least s.f. with correct units 1 1ci Largest value is 6.3 cm (Accept 6.0-6.5 cm) Corresponds to the width of the bull dog clip provided OR Largest value is 8 cm (Accept 7-14 cm) Oscillation dies down too quickly when w is larger. 1 1cii • All headings accurately labelled with correct units. • Repeated readings for t • At least 6 sets of data collected 1 • w / cm recorded to 0.1 cm • t / s recorded 0.01 s • t > 10s • N, n recorded 1 • t average calculated and given to 0.01 s (same d.p. as t) • T calculated and given to least s.f. • 1/w calculated and given to least s.f. 1 If table is split (e.g. 1/w or T in a separate table, minus 1 mark from 1cii MINUS 1 1di • Axes labelled with correct quantity and corresponding units • Labelled at every 2 cm or 4 cm interval • Plotted points cover at least half of the grid given 1 • All points from table are plotted correctly (should not have more crosses than data sets from the table) • Best fit straight line drawn with anomalous points clearly labelled as “anomalous”, where applicable (not allowed to consider points as anomalous if data set is less than 6 sets) 1

2 ©EJC 2023 9749/04/J2H2Prelim/2023 Qns Answer Marks 1dii • One point clearly identified – this point cannot be an anomalous point. • Expected T read to half the precision of a grid • Measured T can be read to the precision of the grid OR can be read from the table directly. • Difference in T calculated with correct units 1 1diii If candidate drew a straight line: If the relationship is valid, the plot of T against 1/w should give a line through the origin. OR The relationship is not valid because the best fit (straight) line does not pass through the origin. OR, if candidate drew a curve: If the equation is valid, the plot of T against 1/w should give a straight line through the origin. 1 The y-intercept of the graph is 0.6, and the difference of the y-intercept to zero is larger than the maximum difference between the best fit line and the data points as calculated in (d)(i), which is 0.3. Hence, the graph is a straight line which does not pass through the origin, and therefore, the results do not support the relationship. OR, if candidate drew a straight line: From the plot in (d)(i), the best fit line fit a curve, not a straight line. The difference in (d)(ii) shows a maximum percentage difference of ____ for the value of T based on a best fit straight line, which is larger than 10%. Hence, my results do n