5 13142.02 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) 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) 6 13142.02 7 13142.02