Mark Scheme – As Physics – 7407-2 – June .

MARK SCHEME – AS PHYSICS – 7407/2 – JUNE 2023/2024 Question Answers Additional Comments/Guidance Mark AO details 01.1 Max one from:  internal ray is a radius (of the block) OR internal ray travels along a normal OR ray meets (glass-air) boundary at 90 OR angle of incidence is zero (so angle of emergence/refraction is zero) 1 2.1c 01.2 Straight line ruled from centre of protractor through ABC  Takes a pair of readings: 24 or 66; and angle consistent with their line  Use of Snell’s Law with their angles  1.48 or 1.52  for 1 line must be reasonable and must pass through intersection of the cross-wires and must not pass above the centre of A or below the centre of B Must be between 0° and 90° Must be a positive value to 3 sf. 4 3.2b 2.1h 2.1h 2.1h 01.3 1.47 or 1.471  Reject 1.5 or 4 sf; ignore any unit written 1 3.1a 6 Distribution of this document is illegal S - The Marketplace for Revision Notes & Study Guides MARK SCHEME – AS PHYSICS – 7407/2 – JUNE 2020 01.4 0.08 (mm)  Only acceptable answer 1 3.1a Question Answers Additional Comments/Guidance Mark AO details 01.5 Calculates one percentage uncertainty OR Calculates max or min value  Adds their percentage uncertainties OR 0.5(max − min) attempt to use percentage n = × 100  1.47 1.4(%)  For 1 allow ecf from 01.4; expected answers are % uncertainty in (R2 – R0) = 100 × 0.08 = 0.56(0)% 14.28 % uncertainty in (R2 – R1) = 100 × 0.08 = 0.82(4)% 9.71 n = 14.28 - 0.08 = 1.45(0); min 9.71 + 0.08 n = 14.28 + 0.08 = 1.49(1); max 9.71 - 0.08 Ecf for 2 from wrong percentage uncertainties or wrong max or min values Condone 3 or 4 sf 3 3.1b 3.1b 3.1b Total 10 7 Distribution of this document is illegal S - The Marketplace for Revision Notes & Study Guides MARK SCHEME – AS PHYSICS – 7407/2 – JUNE 2023/2024 Question Answers Additional Comments/Guidance Mark AO details 02.1 to limit (maximum) current (when variable resistor is set to zero)  to prevent overheating (of cell) OR to prevent damage to cell OR otherwise cell would discharge quickly  Accept ‘so cell is not short-circuited’ for 1 ‘to avoid damaging components’ is not enough for 2 2 3.2b 3.2b 02.2 Line ruled through bottom of second error bar and top of ninth (3rd from right) error bar  Determines their gradient, with x ≥ 0.2 (A)  (–)1.0 ± 0.1 (/ V A–1)  Ignore unit if given. Allow tolerance of 2 mm inside either error bar. Expect to see 2 sf in any answer 3 3.1a 2.1h 2.1h 02.3 Attempt to calculate mean of their Gmin and –1.3  1.1 ()  Allow positive G values Ecf from 02.2. 1 mark max if r given as negative 2 3.1a 3.1a 8 Distribution of this document is illegal S - The Marketplace for Revision Notes & Study Guides MARK SCHEME – AS PHYSICS – 7407/2 – JUNE 2023/2024