YIJC 2024 JC2 PRELIM H2 Phy P4 Soln

YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME Suggested Solution & Marking Scheme CG INDEX NO PHYSICS Paper 4 Practical Candidates answer on the Question Paper. Additional Materials: As listed in the apparatus list. 9749/04 26 August 2024 2 hours 30 minutes READ THESE INSTRUCTIONS FIRST This document consists of 7 printed pages and 1 blank page. This - Blank Page - This document consists of 22 printed pages and 4 blank pages. Shift Laboratory For Examiner’s Use 1 /11 2 /11 3 /22 4 /11 Total /55 Write your name and class in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. Answer all questions. You will be allowed a maximum of one hour with the apparatus for Questions 1 and 2, and a maximum of one hour for Question 3. You are advised to spend approximately 30 minutes on Question 4. Write your answers in the spaces provided on the question paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working, where appropriate, in the spaces provided. Give details of the practical shift and laboratory, where appropriate, in the boxes provided. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 2 BLANK PAGE

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 3 1 In this experiment, you will determine the resistivity of a metal. (a) Set up the circuit as shown in Fig. 1.1. Fig. 1.1 Record the voltmeter reading E. E = ………………………………. V Set up the circuit shown in Fig. 1. 2. Fig. 1.2 (not to scale) P and Q are crocodile clips. The distance between the nail and Q is x, as shown in Fig. 1.2. Adjust the position of Q until x is approximately 45 cm. Close the switch. The voltmeter reading is V. Measure and record x and V. x = ………………………………. V = ………………………………. [1] Open the switch. 3.30 V 45.0 cm 1.51 V • x is between 44.0 cm & 46.0 cm with precision 0.1 cm • Range of V is 1.00 V to 2.00 V with precision 0.01 V [1] Marker’s comment: Common mistake where students do not include the units. Some students made errors in the d.p. when recording in metre.

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 4 (b) Vary x by adjusting the position of Q on the wire. For each value of x, measure V. Record your results in a table. x/cm V / V 1 V / V-1 5.0 25.0 35.0 45.0 55.0 85.0 1.35 1.43 1.47 1.51 1.56 1.73 0.741 0.699 0.680 0.662 0.641 0.578 [3] (c) It is suggested that V and x are related by the expression: 1 = Ax+ BV where A and B are constants. Plot a suitable graph to determine values of A and B. A = ..…………………………… B = ….…………………………. [5] Presentation of Measured (M) Data • At least 6 sets of x and V in the table. • Range > 70.0 cm • Precision of x is 0.1 cm • Precision of V is 0.01 V • (x = 45 cm point should be tabulated) [1] Table Headers (H) • Column heading must contain a quantity and a unit (eg x/cm or x (cm). • If no derived data, no mark [1] Calculated (C) Data • Correction calculation for 1/V with appropriate s.f. • If no derived, no mark [1] • Gradient correctly calculated and in 2 or 3 s.f. • y-intercept correctively derived from graph (within 1/2 small sq division) or correctly calculated. In 2sf/3sf [1] • Correct linearisation • Equate gradient to A with correct units (V-1m-1 or V-1cm-1) • Equate y-intercept to B with correct units (V−1) [1] Gradient = A = 0.732-0.589 -0.2040.10-0.80 = A = -0.204 V-1 m-1 To find B Based on y = mx + c 0.732 = -0.204(0.10) + B B = 0.752 V-1 − 0.204 V−1 m−1 0.752 V−1 Marker’s comment: 1. Common mistake in not including the units for 1/V. 2. The range is often incorrect – a range of 70 cm is expected. 3. Students should take care in rounding off the value for the calculated values. 4. Some students made errors in the d.p. when recording in metre. Marker’s comment: 1. Many students were not careful with the units of A and B, either not stating any units, or stating the wrong units. 2. Some students still mistakenly read off the vertical intercept when the graph does not start from x = 0. 3. Some wrongly used data from the table to calculate B. Points must be read off from the graph drawn.

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 5 Sensible choice of scale for axis; no odd scales; plotted graph is more than half page. Axes are labelled. Scale marking must be no more than 2 big squares apart. [1] All points on table are plotted. Plotted points within half small squares in both x and y directions. [1] Line of best fit, gradient coordinates separated at least half length of plotted line. Line must not be ‘kinked’ or thicker than half a small square. Anomalous point must be labelled. [1] Marker’s comment: 1. 1 box to 0.15 is an awkward scale commonly seen in student’s answers. 2. Students who chose good scales committed significantly fewer errors in calculating gradient/y-intercept compared to those with poorly chosen scales. 3. Students should note that graphs can be plotted in landscape (as shown).

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 6 (d) Theory suggests that A is given by the equation   4 2A= d ER where d is the diameter of the wire, R is 22  and  is the resistivity of the metal. Determine a value for .  = …………………………..  m [2] [Total: 11] Range of d is 0.25 – 0.35 mm Repeated readings and finding average [1] Correct calculation of . Allow for ECF. s.f. consistent with raw data. 2/3 sf. rho is between 10-7 to 10-5 ohm m [1] ( ) 2-3 4(-0.2043) = - 0.31×10 (3.30)(22)    = 1.1 x 10-6 m Average diameter d1 = 0.31 mm d2 = 0.31 mm Average diameter d = 0.31 mm 1.1 x 10-6 Marker’s comment: Many students had readings that did not make sense. Most likely some still do not know how to read the micrometre, and others did not realise that this part required measurement of the diameter after the 1h was up.

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 7 2 In this experiment, you will investigate the oscillations of a loaded wooden strip. (a) You have been provided with a rectangular wooden strip with a hole in its centre. Use some of the Blu-Tack to attach the two 100 g masses as near as possible to one end of the strip, as shown in Fig. 2.1 and Fig. 2.2. Fig. 2.1 Fig. 2.2 The distance between the centre of the masses and the hole is d, as shown in Fig. 2.1. Measure and record d. d = ……………………… [1] Blu-Tack Value for d with unit. Range 23.0 cm to 25.0 cm Precision is 0.1 cm Repeated reading not required. [1] 24.0 cm Marker’s comment: 1. Some values are outside the acceptable range.

©YIJC 9749/04/YIJC/PRELIM/2024 [Turn over 8 (b) (i) Attach the two 20 g masses to the other end of the strip so that the distance between the centres of these masses and the hole is equal to d. Insert the nail into the hole in the centre of