ACJC 2024 J2 H2 Physics Prelim P4 Soln

Anglo-Chinese Junior College 2024 H2 Preliminary Exam Paper 4 Guide H2 (9749) Physics JC2 2024 Page 1 of 5 Q1 (a) Value of w (measured to the nearest mm) with unit and in the range 69.0 – 71.0 cm. Value of I1 (measured to the nearest 0.1 mA) with unit. (b) Correct calculation of I1I2 with unit. Value of I2 is smaller than value of I1. (c) Four sets of readings of w, I 1 and I 2 and, the range of w is more than or equal to 30.0 cm Column headings: Each column heading must contain a quantity, a unit and a separating mark where appropriate. The presentation of quantity and unit must conform to accepted scientific convention, e.g. -11 /mw , 42 12 / 10 A−II . Significant figures: All values of 1 w must be given to the same number of s.f. as (or one more than) the number of s.f. in w. All values of 12II must be given to the same number of s.f. as (or one more than) the least number of s.f. in I 1 and I 2. (d)(i) Plotting of points: All observations in the table must be plotted on the grid. Diameter of plotted points must be ⩽ half a small square. Points must be plotted to an accuracy of half a small square in both x and y directions. Line of best fit: There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled). Lines must not be kinked or thicker than half a small square. (d)(ii) Gradient: The hypotenuse of the triangle used must be greater than half the length of the drawn line. Both read-offs must be accurate to half a small square in both the x and y directions. Method of calculation must be correct (not x / y). Gradient sign on answer line matches graph drawn. Value of P = candidate’s gradient Unit for P: A2 m Vertical intercept: Correct read-off from a point on the line and substituted into y = mx + c or an equivalent expression. Read-off accurate to half a small square in both x and y directions. Value of Q = candidate’s intercept Unit for Q: A2 (d)(iii) When 1 0w = , w = . This is not possible to obtain as we only used one metre in length for the wire.

Anglo-Chinese Junior College 2024 H2 Preliminary Exam Paper 4 Guide H2 (9749) Physics JC2 2024 Page 2 of 5 Q2 (a)(i) Zero error recorded. Value of D1 (measured to the nearest 0.002 cm) with repeated readings and in the range 3.500 – 4.500 cm. Correct calculation of C1 with unit. (a)(ii) Justification of the number of significant figures of C1 linked to the number of s.f. in M1 and D1. C1 has the same number of s.f. as (or one more than) the least number of s.f. in M1 and D1. (a)(iii) Value of t (measured to the nearest 0.1 s) with repeated readings. (a)(iv) Percentage uncertainty in t expressed to 1 or 2 s.f. based on an absolute uncertainty of 0.5 – 0.8 s. Correct method of calculation to obtain percentage uncertainty. percentage uncertainty in 100%tt t = (b)(i) Zero error recorded. Value of D2 (measured to the nearest 0.002 cm) with repeated readings and in the range 6.000 – 8.000 cm. Correct calculation of C2 with unit. (b)(ii) Value of t (measured to the nearest 0.1 s) with repeated readings and value of t in (b)(ii) is greater than value of t in (a)(iii). (c) Two values of k calculated correctly with the correct unit. Allow 2 or 3 s.f. (d) Calculation of percentage difference between candidate’s two k values. Valid comment consistent with the calculated values of k, testing against a criterion stated by the candidate. (e) Zero error recorded. Value of d (measured to the nearest 0.002 cm) with repeated readings and in the range 0.550 – 0.650 cm. Correct calculation of two values of a with unit. Value of a with larger N is smaller than value of a with smaller N. Allow 2 or 3 s.f.

Anglo-Chinese Junior College 2024 H2 Preliminary Exam Paper 4 Guide H2 (9749) Physics JC2 2024 Page 3 of 5 Q3 (a)(i) Value of h (measured to the nearest mm) with unit and in the range 59.0 – 61.0 cm. (a)(ii) Value of t1 (measured to the nearest 0.1 s). Evidence of repeated measurement of nT1 where 1 20.0 snT  . T1 is expressed to the correct s.f. with unit. (b)(i) Value of t2 (measured to the nearest 0.1 s). Evidence of repeated measurement of nT2 where 2 20.0 snT  . T2 is expressed to the correct s.f. with unit. (b)(ii) Six sets of readings of h, n1, t1, n2, t2. Range of h is more or equal to 30 cm. Precision of raw values: Value of h measured to the nearest mm Value of t1 and t2 measured to the nearest 0.1 s. Correct precision of raw values in (a)(i), (a)(ii) and (b)(i). Column headings: Each column heading must contain a quantity, a unit and a separating mark where appropriate. The presentation of quantity and unit must conform to accepted scientific convention, e.g. -11 /mh , 2 2 2 21 /sTT− . Significant figures: All values of 1 h must be given to the same number of s.f. as (or one more than) the number of s.f. in h. All values of 22 21TT− must be given to the same number of s.f. as (or one more than) the number of s.f. in T1 and T2. Calculation: Correct calculation of 1 h and 22 21TT− . (c) Linearisation: Plotting statement to linearise the equation. Axes: Sensible scales must be used, no awkward scales (e.g. 3:10 or fractions). Scales must be chosen so that the plotted points occupy at least half the graph grid in both x and y directions. Scales must be labelled with the quantity that is being plotted. Plotting of points: All observations in the table must be plotted on the grid. Diameter of plotted points must be ⩽ half a small square. Points must be plotted to an accuracy of half a small square in both x and y directions. Line of best fit: There must be an even distribution of points either side of the line along the full length. Allow one anomalous point only if clearly indicated (i.e. circled or labelled). Lines must not be kinked or thicker than half a small square. Gradient: The hypotenuse of the triangle used must be greater than half the length of the drawn line. Both read-offs must be accurate to half a small square in both the x and y directions. Method of calculation must be correct (not x / y). Gradient sign on answer line matches graph drawn. Vertical intercept:

Anglo-Chinese Junior College 2024 H2 Preliminary Exam Paper 4 Guide H2 (9749) Physics JC2 2024 Page 4 of 5 Correct read-off from a point on the line and substituted into y = mx + c or an equivalent expression. Read-off accurate to half a small square in both x and y directions. OR Intercept read directly from the graph, with read-off at 1 0h = , accurate to half a small square. Value of X = candidate’s gradient and value of Y = candidate’s vertical intercept. The values must not be fractions. Unit for X: s2 m, s2 cm or s2 mm and unit for Y: s2. (d) Value of m (measured to the nearest 0.01 g) with unit and in the range 68.0 – 78.0 g. Correct calculation of M with unit. (e) Line labelled W with steeper gradient and no change to vertical intercept. (f) • Set up the experiment as shown in Fig. 3.2. • Vary the mass m of the pen