Cambridge IGCSE Physics 0625 — 2022 May/June Paper 6 · Variant 3

1 A student investigates the forces supporting a metre rule. He uses the apparatus shown in Fig. 1.1. The scale of the metre rule faces upwards. clamp newton meter P newton meter Q stand metre rule 0.0 cm mark d loop of thread 1.00 N load bench Fig. 1.1 (a) The student ensures that the metre rule is horizontal. Briefly describe how to check that the rule is horizontal. You may draw a diagram if it helps to explain your answer. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (b) (i) The student sets the distance d between the 0.0 cm mark and the 1.00 N load as shown in Fig. 1.1. He moves the thread supporting the 1.00 N load so that it is at the mark on the metre rule shown in Fig. 1.2. thread supporting 1.00 N load 14 15 16 17 Fig. 1.2 Record the distance d indicated on Fig. 1.2. d = .................................................... cm [1] (ii) The readings on newton meter P and newton meter Q are shown in Fig. 1.3. N N 0.0 0.0 0.5 0.5 1.0 1.0 1.5 1.5 2.0 2.0 2.5 2.5 newton meter P newton meter Q Fig. 1.3 Record FP, the reading on newton meter P shown in Fig. 1.3. Record FQ, the reading on newton meter Q shown in Fig. 1.3. FP = ............................................................... FQ = ............................................................... [1] (c) The student moves the 1.00 N load to distances d = 25.0 cm, d = 35.0 cm, d = 45.0 cm, d = 55.0 cm and d = 65.0 cm. He reads the value FP on newton meter P and the value FQ on newton meter Q. His readings are shown in Table 1.1. Table 1.1 d / cm FP / N FQ / N 25.0 1.81 1.19 35.0 1.70 1.30 45.0 1.56 1.45 55.0 1.44 1.55 65.0 1.31 1.69 Using the values from Table 1.1, plot a graph of FP / N (y-axis) against d / cm (x-axis). On the same axes, and using the same scales, plot a graph of FQ / N (y-axis) against d / cm (x-axis). Draw two best-fit lines, one for each set of plots. Show clearly on your graph which line is for FP and which line is for FQ. FP / N FQ / N [5] (d) From your graph, determine F0, the value of FP where the two best-fit lines cross. F0 = ............................................................... Calculate the weight WR of the metre rule, using the equation WR = (2 × F0) – k, where k = 1.00 N. WR = ............................................................... [2] (e) Another student does the experiment with the same equipment. He reads values of FP which are the same as those in Table 1.1 but his values of FQ are all 0.10 N greater than those in Table 1.1. Suggest a reason for this difference. Assume that the values in Table 1.1 are correct. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] [Total: 11]

Mark scheme: 1(a) any valid method e.g. check equal distance between rule and bench at two places OR use set square/protractor between stand and rule OR line up with suitable (named) surface 1 1(b)(i) d = 15.2 (cm) 1 1(b)(ii) FP = 1.05 (N) and FQ = 1.95 (N) 1 1(c) graph:  x-axis labelled with quantity and unit 1  suitable scales (plots occupying at least 3 large squares in both directions) 1  plots all correct to ½ small square and precise plots 1  2 well judged lines and thin lines 1  intersection at d = 50.0 cm to 1 small square 1 1(d) F0 present and WR in range 1.8 (N) to 2.2 (N) 1 WR expressed to 2 or 3 significant figures and with unit of N 1 1(e) forcemeter Q has zero error OR has not been set to 0 at start 1

More questions on Physical quantities and measurement techniques

2 A student investigates how the volume of water affects the rate at which water in a beaker cools. She uses the apparatus shown in Fig. 2.1. thermometer stand beaker bench 30 20 10 0 Fig. 2.1 (a) (i) Record the room temperature θR shown on the thermometer in Fig. 2.1. θR = ......................................................... [1] (ii) Describe one precaution that can be taken to ensure that temperature readings in the experiment are as accurate as possible. ........................................................................................................................................... ..................................................................................................................................... [1] (b) The student pours a volume of 150 cm3 of hot water into the beaker and records the temperature θ at time t = 0. She records the temperature of the water in the beaker every 30 s. She tips the water out and pours a volume of 50 cm3 of hot water into the beaker. The student repeats the temperature measurements for this volume of water. Her readings are shown in Table 2.1. Complete the headings in Table 2.1. Table 2.1 beaker beaker with 150 cm3 of hot water with 50 cm3 of hot water t / θ/ θ/ 0 88.0 86.0 30 86.0 82.0 60 84.0 79.0 90 82.5 76.5 120 81.0 74.5 150 79.5 73.0 180 78.5 72.0 [1] (c) Write a conclusion stating how the volume of water affects the rate of cooling of the water. Justify your answer by reference to the results. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (d) (i) Using the results for 50 cm3 of water, calculate the average cooling rate x for the first 90 s of the experiment. Use the readings from Table 2.1 and the equation θ0 – θ90 x = T where T = 90 s and θ0 and θ90 are the temperatures at t = 0 and t = 90 s. Include the unit for the cooling rate. x = ......................................................... [2] (ii) Another student does this experiment with the same starting temperature but in a room with a much higher room temperature than θR from (a)(i). State how this affects his value of x in d(i). Explain your answer by reference to the results in Table 2.1 for the beaker with 50 cm3 of hot water. statement .......................................................................................................................... explanation ........................................................................................................................ ........................................................................................................................................... ........................................................................................................................................... [2] (e) Some thermal energy is lost from the sides of the beaker. The student wishes to find out how much this loss of thermal energy affects the cooling rate of 50 cm3 of water. Briefly describe an additional experiment that the student can carry out to investigate this. Explain how the results can be used to determine how much this loss affects the cooling rate. additional experiment ............................................................................................................... ................................................................................................................................................... use of results ............................................................................................................................ ................................................................................................................................................... [2] [Total: 11]

Mark scheme: 2(a)(i) 1 2(a)(ii) suitable precaution e.g. line of sight perpendicular to scale OR wait until reading stops rising (at start) 1 2(b) s, °C both correct 1 Question Answer Marks 2(c) statement matching readings in table 1 comparison of temperature changes over 180 s, matching statement 1 2(d)(i) x = 0.106 1 unit °C / s 1 2(d)(ii) value of x will be less/lower 1 temperature difference between beaker and room is less and values from table referred to 1 2(e) repeat experiment with a lid 1 (calculate cooling rate) subtract from x to find cooling rate without transfer from sides OR a comparison of cooling rates 1

More questions on Transfer of thermal energy

3 Some students determine the focal length of a converging lens by different methods. Method 1 One student uses the apparatus shown in Fig. 3.1. mirror illuminated triangle f1 lens card bench Fig. 3.1 (a) The student sets the distance between the illuminated triangle and the mirror to 40 cm. He moves the lens until he sees a sharp image of the triangle on the card, by the side of the illuminated triangle. (i) On Fig. 3.1, measure the distance f1 between the illuminated triangle and the lens. f1 = ............................................................... Fig. 3.1 is drawn to 1/5th scale. Calculate the actual distance F1 between the illuminated triangle and the lens in this experiment. This is a value for the focal length of the lens. F1 = ............................................................... [2] (ii) Briefly describe a technique to obtain an image on the card that is as sharp as possible in this experiment. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] Method 2 Another student sets up apparatus as shown in Fig. 3.2. illuminated triangle U screen lens card bench Fig. 3.2 (b) The student sets the distance between the illuminated triangle and the lens to U = 20.0 cm. She moves the screen until a sharp image of the triangle appears on the screen. (i) Measure hO, the height of the illuminated triangle as shown in Fig. 3.3. hO = ............................................................... Measure hI, the height of the image on the screen as shown in Fig. 3.4. hI = ............................................................... [1] hI hO Fig. 3.3 Fig. 3.4 (ii) Describe one difficulty when measuring the height of the image in this type of experiment. Suggest an improvement to overcome this difficulty. difficulty ............................................................................................................................. ........................................................................................................................................... improvement ..................................................................................................................... ........................................................................................................................................... [2] hO (iii) Calculate a value W using the equation W = . hI W = ............................................................... Calculate a second value F2 for the focal length of the lens, using the equation U F2 = (W + 1). F2 = ............................................................... [2] (c) A student suggests that F1 and F2 should be equal. State whether the results support this suggestion. Justify your statement with reference to the results. statement .................................................................................................................................. justification ................................................................................................................................ ................................................................................................................................................... [2] (d) Describe one precaution that can be taken to obtain reliable measurements of F1 and U in the experiment. ................................................................................................................................................... ............................................................................................................................................. [1] [Total: 11]

Mark scheme: 3(a)(i) f1 = 3.1 (cm) 1 F1 = 15.5 (cm) 1 3(a)(ii) move lens backwards and forwards slowly OR move lens slowly 1 3(b)(i) hO = 1.2 (cm) and hI = 5.1 (cm) 1 3(b)(ii) hand gets in way of light 1 mark on screen and measure later OR use screen with scale OR use translucent screen and measure at rear 1 Question Answer Marks 3(b)(iii) F2 = 16.1 or 16.2 (cm) 1 F2 expressed to 2 or 3 significant figures with matching unit 1 3(c) statement matching results 1 values within limits of experimental accuracy/owtte and values quoted in justification 1 3(d) any one from: mark position of lens on holder clamp/place rule on bench ensure screen, lens and object all perpendicular view rule perpendicularly repeat and take average use darkened room/brighter light 1

More questions on Light

4 A student investigates the resistance of a light-dependent resistor (LDR). The resistance of an LDR changes as the intensity of light falling on it varies. V The resistance R of the LDR is calculated using the equation R = I where V is the potential difference (p.d.) across the LDR and I is the current in the LDR. Plan an experiment to investigate how the light intensity affects the resistance of an LDR. The apparatus available includes: an LDR equipment to connect the circuit, part of which is shown in Fig. 4.1 a lamp with a power supply. In your plan, you should: • complete the circuit diagram in Fig. 4.1 to show a voltmeter connected to measure the potential difference across the LDR • state how the light intensity falling on the LDR will be varied and list any additional apparatus needed • explain briefly how to do the experiment, including any precautions taken to ensure reliable results • state one key variable to be kept constant • draw a table, or tables, with column headings, to show how to display the readings (you are not required to enter any readings in the table) • explain how to use the readings to reach a conclusion. A power supply LDR Fig. 4.1 .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. .................................................................................................................................................................. ............................................................................................................................................................ [7]

Mark scheme: 4 MP1 apparatus: voltmeter – correct symbol in parallel with LDR 1 MP2 independent variable: statement identifying the independent variable e.g. light intensity, distance, current, voltage 1 MP3 method: measure independent variable (e.g. metre rule to measure distance between lamp and LDR) measure p.d. and current calculate resistance of LDR 1 MP4 repeat for new value of independent variable 1 MP5 control variable: any variable appropriate to independent variable (e.g. distance from lamp to LDR if current through lamp is the independent variable, p.d., power, intensity) 1 MP6 table: columns, with units, for independent variable, measured dependent variable and resistance (not just resistance without raw measurements) 1 MP7 analysis: compare resistance values (in table) to see if change in independent variable produces change in resistance plot line graph (with axes specified) 1

More questions on Electric circuits