FHSS 2026 Physics P2 MS

2026 FHSS Prelim O Level Physics Mark Scheme 1 (a) 400 m [1] (b) v = gradient of s-t graph v = 300/20 [1] = 15 m/s [1] (c) Velocity is decreasing OR deceleration [1] Gradient is decreasing [1] (d) Label v-axis Horizontal line at 15 m/s from 0s to 20s Straight line or concave line or convex line from 20s to 33s from 15 m/s to 0 m/s Horizontal line at 0 m/s from 33s to 70s 4 points – 3m 2 or 3 points – 2m 1 point – 1 m [3] 2 (a) (i) P = F/A P = 150/0.020 [1] P = 7500 N/m2 [1] (ii) 7500 = upward force/0.016 [1] upward force = 120 N [1] (b) (i) Vibration of particles transfer energy to neighbouring layer. Neighbouring layer vibrate faster and transfer to the next layer. [1] Free moving electrons transfer kinetic energy when colliding with particles that are vibrating slower. [1] (ii) Water is heated, becomes less dense and rises [1] Cooler water, which is denser, sinks to take its place. [1] 3 (a) Resultant force = 0 N [1] Resultant moment = 0 Nm OR Total clockwise moment about a pivot is equal to total clockwise moment about the same pivot. [1] (b) W = (12)(10) = 120 N [1] t / s v m/s/ 0 10 20 30 40 50 60 70 0 1 2 3

2026 FHSS Prelim O Level Physics Mark Scheme (F)(0.50) = [(3.00/2)-0.50](120) [1] F = 240 N [1] (c) 𝑃 = (240)(0.20) 1.5 (ecf) [1] 𝑃 = 32𝑊 [1] 4 (a) Oscillation of particles is parallel / same direction as direction of wave travel [1] (b) Difference: frequency of ultrasound is greater than 20000 Hz but audible sound falls between 20 Hz and 20000 Hz. (accept: less than 20000 Hz) [1] Similarity: both require medium to transfer OR both transfer energy (reject longitudinal wave – given in (a)) [1] (c) v = 2d/t 1500 = (2)(d)/0.40 [1] d = 300 m [1] (d) v = 𝑓λ 1500 = (40000)(λ) [1] λ = 0.0375 m [1] (e) Prenatal scanning OR detect cracks in metals OR clean delicate objects OR medical scanning of soft tissue [1] 5 (a) All rays parallel to principal axis converging to a point after passing through the convex lens. [1] (b) Arrow on every light ray One ray parallel to principal axis One ray through F One ray through optical centre Full image labelled “𝐼” and inverted arrow at 2F 5 points – 3m 3 to 4 points – 2m 2 points – 1m [3] (c) Size enlarge [1] Distance increases [1] F1 F2 10.0 cm

2026 FHSS Prelim O Level Physics Mark Scheme 6 (a) (i) Current in a conductor is directly proportional to the potential difference across it provided the external (or physical) conditions remain constant. [1] (ii) R. straight line graph passing through the origin. [1] (iii) R = V/I R = 6.0/0.42 [1] R = 14.286 Ω R = 14.3 Ω (3 sf) OR 14 Ω (2 sf) [1] (b) (i) Effective resistance decreases [1] Current increases. [1] (ii) Under dark condition, potential difference across LDR is higher than across 50 Ω resistor. When the potential difference exceeds 10 V, the lamp lights up. [1] Under bright condition, potential difference across LDR is lower than across 50 Ω resistor. When the potential difference falls below 10 V, the lamp switches off. [1] 7 (a) (i) up [1] (ii) 1 Up [1] 2 When AB is nearer to north pole, it will turn towards South pole. But when AB is nearer to south pole, it will turn towards North pole. It reaches a state where the resultant force becomes zero and the coil remains vertical OR Direction of current is not reversed every half rotation so it cannot rotate continuously OR Force on AB is always upwards and force on CD is always downwards regardless of orientation. [1] (b) (i) Like charges repel [1] Negative charges nearer to negatively charged metal sphere are repelled to the right side into the earth, forming the momentary deflection in the galvanometer. [1] (ii) (iii) At least 3 positive charges on rod – 1m Current from galvanometer to copper plate – 1m [2] 8 (a) 15 protons and 17 neutrons [1] (b) {𝑢 = 32, 𝑣 = 16} – 1m {𝑥 = 0, 𝑦 = -1} – 1m [2] + + +

2026 FHSS Prelim O Level Physics Mark Scheme (c) (i) Radiation in an environment where no radioactive source has been deliberately introduced. [1] (ii) 𝑐𝑜𝑢𝑛𝑡 𝑟𝑎𝑡𝑒: 640 → 320 → 160 → 80 𝑑𝑎𝑦𝑠: 0 → 14 → 28 → 42 [1] Time taken = 42 days [1] (d) treat cancer [1] Does not remain in body for too long [1] 9 (a) Gravitational field strength is equal to initial acceleration [1] Air resistance is zero. OR the only force is the weight. [1] (b) W – f = ma (2)(12) – 4 = (2)(a) [1] a = 10 m/s2 [1] (c) Weight in L is larger than weight in K [1] Lower terminal velocity in L implies greater air resistance in L [1] L has denser atmosphere OR L has greater air density [1] (d) (i) 8.0 N [1] (ii) Energy in gravitational potential store of probe is transferred mechanically to energy in internal store of the probe. mechanically – 1m gravitational potential store, internal store – 1m [2] 10 (a) (i) volume = (π)(40)2(12) = 60320 m3 = 60300 m3 (3 sf) OR 60000 m3 (2sf) [1] (ii) 𝜌 = 𝑚 𝑉 1.2 = 𝑚 60320 m = 72384 kg [1] Ek = ½ mv2 Ek = ½ (72384)(12)2 [1] Ek = 5.212  106 J Ek = 5.21  106 J (3 sf) OR 5.2  106 J (2 sf) [1] (b) (i) 160 V [1] Rate of change of magnetic flux linkage is the maximum. [1] (ii) 1m – peak at 80 V. 1m – double period. [2] (c) Low current, less energy loss along transmission lines [1] (d) Disadvantage: depends on weather / kills birds that strike the windmill / use a lot of space [1] V t -400 -200 0 200 400

2026 FHSS Prelim O Level Physics Mark Scheme 11 (a) Control amount of current flowing through OR control resistance of circuit. [1] (b) Particles vibrate slower at 20 °C than at 60 °C. [1] (c) 𝑟𝑎𝑡𝑒 = 68 − 20 300 = 0.16 ℃/𝑠 [1] (d) (i) Pt = mcΔ𝜃 (50)(300) = (0.80)(c)(48) [1] c = 391 J/(kg °C) (3 sf) or c = 390 J/(kg °C) (2 sf) [1] (ii) Specific heat capacity refers to the energy needed to change one unit mass by one Kelvin but heat capacity refers to the energy needed to change a substance by one Kelvin. [1] (e) (i) More energy needed to raise 1 kg of substance by 1 °C with same heater. Therefore temperature rise is smaller [1] Gradient is gentler [1] (ii) Different substance has different particles [1] Energy needed to change kinetic energy of particles in second metal is greater than energy needed to change kinetic energy of particles in first metal for the same mass. [1] 0m if students use definition.