2021 H2 Phy Prelim Paper 4 Question Paper with Answers (Mark Scheme) (forJCs)

YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO PHYSICS Paper 4 Practical Candidates answer on the Question Paper. No Additional Materials are required. 9749/04 26 Aug 2021 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 17 printed pages and 3 blank pages. ©YIJC [Turn over Marking Scheme 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. 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 boxes 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. Shift Laboratory For Examiner’s Use 1 /16 2 / 6 3 /21 4 /12 Total /55

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1 In this experiment you will investigate an electrical circuit. You are provided with several groups of resistors connected in parallel. (a) Assemble the circuit as shown in Fig. 1.1 A, B, C, D and E are crocodile clips. Measure and record the length Lo of the resistance wire between the ends of A and B, as shown in Fig. 1.1. Lo = …………………………… [1] (b) (i) Select from the groups of resistors connected in parallel, N=4 and connect it across D and E as shown in Fig.1.1. (ii) Close the switch. Move C along the wire until the voltmeter reading is zero. Measure and record the distance L between A and C when the voltmeter reading is zero, as shown in Fig. 1.1. L = …………………………… [1] Open the switch. ©YIJC [Turn over  to nearest mm with units  0.580 m  Lo  0.620 m [1] 60.0 cm (0.600 m)  nearest mm with units  L depends on N and is less than Lo [1] 16.8 cm (0.168 m) 3

(c) Select a different group of resistors and repeat (b)(ii) until you have at least six sets of values of N and L. Record your results in a table. Include values of and in your table of results. N L / m 2 0.098 0.500 10 3 0.141 0.333 7.09 4 0.168 0.250 5.95 5 0.196 0.200 5.10 6 0.220 0.167 4.55 7 0.245 0.143 4.08 8 0.262 0.125 3.82 [6] (d) (i) It is suggested that the quantities L and N are related by the equation where a and b are constants. Plot a suitable graph to determine a and b. Give appropriate units. A graph of against is plotted with the gradient equals to a and the y-intercept equals to b. Gradient =  a = 17.3 m-1 ©YIJC [Turn over  Award 2 mk if collected 6 or more sets of data wo assistance. Award 1 mk if collected 5 sets of data wo assistance. Zero if less than 5 sets. [2]  Column headings must contain a quantity and a unit where appropriate eg [1]  Raw values for L must be given to nearest mm (precision) [1]  Number of s.f. for calculated values should be same or one more than that for L. [1]  Correct calculation for 1/N and 1/L. [1]  Allow for one miscalculation.  Correct linearising of equation. Not necessarily to be that given above [1]  The hypotenuse of the gradient triangle must be greater than half the length of the drawn line of best fit. Gradient points are read off accurate to half a small square. [1]  Zero mark for above if gradient obtained from plotting reverse axis (x-y graph)  Calculation for gradient is correct. Value for a is in 3 s.f. with correct units (m-1 or cm-1) [1] 4

Determining the y-intercept Substituting (0.450, 9.40) into y = ax + b 9.40 = (17.3)(0.450) + b b = 1.62 m-1 a = …………………………… b = …………………………… [7] ©YIJC [Turn over  Either correct read off (with ½ small square precision) from y-intercept (1/N = 0) or by calculation using substitution into y=ax + b.  Value for b is correctly calculated, in 3 .s.f and with correct unit. ECF allowed. [1]  Zero mark if use data point not on the line of best fit for substitution. 17.3 m-1 1.62 m-1 5

©YIJC [Turn over 0.100 0.200 0.300 0.400 0.500 4.00 3.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 (0.150, 4.20) (0.450, 9.40) W Axes [1]  Axes are clearly labelled with units  Sensible scales (no awkward scale eg 3:10)  Scales chosen so that plotted points occupy at least 4 by 6 big squares.  Scale markings should not be more than 2 big squares apart. Plotting of points [1]  Number of plotted points tally with observed data in table.  Diameter of plotted points  half a small square.  Plots accurate to half a small square in both x and y direction. Quality of best fit line [1]  Reasonable line of best fit with even scatter of points.  Line must not be thicker than 1 small square, ‘hairy’ or ‘kinked’.  One anomalous point allowed. To be circled/identified so that it does not influence the line of best fit. 6

(e) Without taking further readings, sketch a line on your graph grid to show the results you would expect if the experiment was repeated with the wire across AB replaced by one with the same length but with a larger resistance per unit length. Label this line W. [1] [Total : 16] ©YIJC [Turn over  The line W is the same as the original line plotted [1]  The line MUST be labelled to show the same line is expected. No mark if line is not labelled clearly. No need for explanation.  The potential difference across the length of wire AB is the same. Thus, the potential divider principle remains the same regardless of the resistance. The potential ratio is the same. When p.d. = 0, by potential divider principle.  In theory, since Lo = 0.60 m b = 1/Lo = 1/0.60 = 1.67 m-1 a = 10/Lo = 10/0.60 = 16.7 m-1 Changing the resistance AB of same length does not impact the graph as Lo is still the same. 7

2 In this experiment, you will investigate the oscillatory motion of a loaded metre rule supported at one end by a spring. (a) Secure the cork in the clamp so that the pin is mounted horizontally. Suspend one end of the rule from the pin by passing the pin through the hole in the rule. The rule should be able to pivot around the pin. The other end of the metre rule has a spring attached to it through a small loop of string at the 0.5 cm mark. Hook the other end of the spring to the rod of another clamp as shown in Fig. 2.1. The clamps should be adjusted so that the rule is approximately horizontal. Fig. 2.1 (b) Hang the loop of string onto the rule to suspend a mass of 350 g a distance d from the pin as shown in Fig 2.2. The mass should be about halfway along the rule. Adjust the position of the clamps to make the rule approximately horizontal again. Fig. 2.2 ©YIJC [Turn over spring pin and cork (clamped) stand clamp rule string at 0.5 cm mark of rule mass of 350 g 8

(c) (i) Based on the scale on the metre rule, record the position of the loop attached to the hanging mass, XA. Record the position of the pin, XB. XA = .…….………………......... XB = .…….……………….