A-level PHYSICS 7408/3A Paper 3 Section A Mark scheme (A GUARANTEED) 100% CORRECT GRADED A+ | LATEST SOLUTIONS |

A-level PHYSICS 7408/3A Paper 3 Section A Mark scheme (A GUARANTEED) 100% CORRECT GRADED A+ | LATEST SOLUTIONS | Question Answers Additional comments/Guidelines Mark AO 01.1 finds d by reading position of (lower end of) detector; subtracts 138 mm or wtte 1 annotates Figure 1 to show suitable use of a recognisable set-square 2 for 1 allow ‘reads / measures height of detector’ / ‘distance from detector to bench’; reject ‘measures height of clamp T’ if ‘subtracts 138’ is not seen; allow ‘subtract distance from source to bench’ / ‘between source and bench’ / ‘height of source from ground’ / ‘position of top / open end / mouth of source’; allow ‘measures height of the detector and the source and finds difference’; condone ‘reversed’ subtraction for 2 expect a triangular 90 set-square in contact with a vertical edge of the ruler, top edge aligned with open end of the detector, eg