7 13142.03 Question 4 Requirements • 15 cm focal length converging lens • lens holder • screen – plain white paper and screen holder • metre rule • power supply 4 light box • ray box • Constructed illuminated object (washer with internal diameter 10 ±1 mm) and crosswires, as shown in Fig. 4.1 used in 2018 AS 3A Illuminated object (washer and cross) construction. Measure the height H of the centre of the lens, mounted in the lens holder above the surface of the bench. Take a sheet of stiff card and use a sharp knife to cut a square aperture of side 40 mm so that the centre of the square is a distance H from the marked edge of the card. The width W of the card depends on the dimensions of the lens holder. Cut a piece of tracing or greaseproof paper about 60 mm square. In the centre of this square use a fi ne felt tip pen (or similar) to mark an “X” with the arms at least 10 mm long. Place the washer over the “X” so that the intersection of the arms is at the centre of the circular hole in the washer. Using transparent self-adhesive tape, attach the washer to the tracing paper. Avoid covering any part of the hole in the washer. Place the tracing paper on the card so that the washer is at the centre of the 40 mm square aperture, with the washer inside the opening. Tape the tracing paper to the cardboard. The completed object is illustrated in Fig. 4.1 tracing paper 60 mm × 60 mm aperture 40 mm × 40 mm washer 10 mm internal diameter tape cardboard marked edge W H Fig. 4.1 Washer and “X” object (not to scale) 13142.03 Preparation Set the metre rule on the desk and place the illuminated washer at the zero mark and the screen at the 100 cm mark. Place the lens in the lens holder and set the lens holder at the 50 cm mark. Action at changeover Reposition the lens holder to the 50 cm mark and check the object and screen are at the 0 and 100 cm marks. 13142.02 ADVANCED SUBSIDIARY (AS) General Certificate of Education 2022 APPARATUS AND MATERIALS LIST Physics Assessment Unit AS 3A Practical Techniques and Data Analysis [SPH31] TUESDAY 10 MAY, MORNING 2 13142.02 PHYSICS UNIT 3 (AS 3A) APPARATUS AND MATERIALS REQUIRED FOR PRACTICAL ASSESSMENT CONFIDENTIAL This document gives preliminary information on the apparatus and materials required for the AS Practical Assessment. Information about the apparatus and materials required for this assessment must NOT be communicated to students. If apparatus/materials have their serial code and/or manufacturer specifi ed then it is essential that centres use this exact apparatus/material. On receipt of this APPARATUS AND MATERIALS LIST, centres must contact Gavin Gray, ggray@ccea.org.uk immediately if they have difficulty in sourcing the specified apparatus or materials. Teachers will be given detailed instructions for setting up the experiment in the Confi dential Instructions for Physics (Advanced Subsidiary) Practical Test, to which they will have confi dential access from April 2022. Teachers will have confi dential access to a copy of the experimental test two working days (48 hours) before the start of the assessment. The AS 3 Practical Techniques Assessment is a test of practical skills consisting of 4 short experimental tests (40 marks). The duration of the assessment is 1 hour. 3 13142.02 The apparatus in the following list will allow for one experiment to be set up for the practical test which makes up questions 1–4. In other words, each set of apparatus (as listed on pages 4 and 5) will accommodate four candidates when doing the circus of experiments. The apparatus can be used for alternative sessions according to the following schedule: Tuesday 10 May - Physics AS 3A (SPH31) (Main Session) 9.15 am–10.15 am (First Alternative) 10.30 am–11.30 am (Second Alternative) 11.45 am–12.45 pm (Third Alternative) 1.15 pm–2.15 pm (Fourth Alternative) 2.30 pm–3.30 pm One set of apparatus for AS 3A (SPH31) will therefore be suffi cient for twenty candidates on Tuesday 10 May if the Main Session and all four alternatives are used. A laboratory may contain one, two, three or more sets of apparatus. This means that four, eight, twelve or more candidates can be accommodated in the same session. To maintain the confi dentiality of details of the practical tests, candidates entered for any of the alternative sessions must be segregated within the centre so that there can be no communication with candidates who have taken an earlier test in any centre. IMPORTANT NOTICE Centres are urged to order items needed for the Physics Practical Tests from the suppliers as soon as possible.