AS PHYSICS 7407/2 Paper 2

AS PHYSICS 7407/2 Paper 2 Question Answers Additional Comments/Guidance Mark AO 01.1 smooth line drawn within half grid square of points  minimum between 32.6 and 32.8 cm  2 AO3-1a Question Answers Additional Comments/Guidance Mark AO 01.2 value of their minimum (cm)  Within a half grid square 1 AO3-1b Question Answers Additional Comments/Guidance Mark AO 01.3 doubles 0.2 OR calculates percentage uncertainty for 0.2 (half range)  0.8 (%)  Correct answer earns both marks CAO 2 AO3-1b Question Answers Additional Comments/Guidance Mark AO 01.4 recognises that node-to-node spacing = /2  recognises the need to divide by 8  2.36  109 (Hz)  Condone use of 7 or 9 3 sf required For example: λ = 0.509 × 2 or 0.127(25) m seen; top line earns 1 8 and bottom line earns 2  3 ×108× 8  f  =  = 2.36  109 (Hz) earns all 3 marks  0.509 × 2   3 ×108× 7  f  =  = 2.06  109 earns 2 marks  0.509 × 2   3 ×108× 9  f  =  = 2.65  109 earns 2 marks  0.509 × 2  Allow 2 marks for 4.72 × 109 (must be 3 sf) 3 2  AO3-1a 1  AO2-1h Question Answers Additional Comments/Guidance Mark AO 01.5 (microwaves are) polarised  1 AO1-1b Total 9 Question Answers Additional Comments/Guidance Mark AO 02.1 correctly deduces extension is 2.6 or 2.7 mm  Should see AC2 = 1.502 + (6.34  102)2; (new) AC = 1.50134; Extension of AC = (1.50134  1.50 =) 0.00134 m or 1.34 mm; and then doubles this Final value must be to at least 2 sf 1 AO2-1h Question Answers Additional Comments/Guidance Mark AO 02.2 evidence of correct working:  6.34 102 sin  = or  = 2.42° seen their new AC OR W = 2T sin  seen OR suitable vector diagram with  labelled tension correctly calculated from 1.0  2×their sin