2026 SSP P1 + P2 + P3 MS

6091/PRELIM/P1/2026 [Turn over SINGAPORE SPORTS SCHOOL PRELIMINARY EXAMINATION 2026 SECONDARY 4 EXPRESS Mark Scheme 1 C 11 D 21 C 31 B 2 A 12 A 22 D 32 D 3 A 13 B 23 A 33 B 4 B 14 A 24 D 34 A 5 B 15 A 25 C 35 C 6 D 16 B 26 D 36 D 7 A 17 A 27 A 37 D 8 C 18 B 28 D 38 A 9 C 19 C 29 C 39 C 10 C 20 B 30 B 40 D

Question Answer Marks 1(a) (pliq =) hρg (in any form) or 0.400 × 1000 × 10 or 2000 or 4000 or 1.02 × 105 (Pa) C1 (p =) patm + hρg (in any form) or 1.00 × 105 + 0.400 × 1000 × 10 or 4000 or 1.02 × 105 (Pa) C1 1.04 × 105 Pa A1 (b)(i) (F =) pA (in any form) or 4000 × 0.025 C1 100  N A1 (b)(ii) (W.D. =) F × x (in any form) or 1.04 × 105 × 0.025 × 0.50 or 4000 × 0.025 × 0.50 or 50 (J) C1 1300  J A1 Question Answer Marks 2(a) molecules close(r) B1 molecules move only small distances (between collisions) or do not move freely B1 molecules move in clusters or slide past each other B1 (b) molecules (in liquid) move faster or gain kinetic energy B1 (c)(i) molecules overcome forces / gain potential energy as the liquid boils B1 (c)(ii) (m =) ρV (in any form) or 0.86 × 50 or 43 (g) C1 (lv =) Q ÷ m (in any form) or 18 000 / 43 or 18 000 / (0.86 × 50) C1 420 J / g or 4.2 × 105 J / kg A1

Question Answer Marks 3(a) electrons travel (a great distance) through the metal or (vibrating) atoms hit (free) electrons B1 electrons hit (distant) particles or transfer energy (to distant atoms) B1 (b) shiny surfaces are poor emitters of radiation B1 B1 (c) less thermal energy emitted as radiation energy lost is proportional to surface area B1 less energy lost to surroundings

Question Answer Marks 4(a) Would not be effective OR No 1 With current on OR the (alternating) current should not be switched off 1 Magnet should be withdrawn from the coil in east west direction slowly 1 OR Magnet would be alternately ma gnetised in different directions (1) Would remain magnetised in the direction occurring at the moment of switching off (1) (b)(i) Coil turns 1 Clockwise/continuously 1 Current (in coil) reverses every half turn/when coil is in vertical position OR force on current in a magnetic fiel d 1 (b)(ii) 1 × (4 × T) 1 2 × (2 × T) 1 3 × (T ÷ 2) 1

Question Answer Marks 5(a) steel (underlined) B1 (b)(i) the direction of the force on a N-pole and left to right / N to S B1 (b)(ii) beam deflects B1 beam deflects into the page B1 moving electrons  / charges constitute a current or left-hand rule or moving electrons / current in a magnetic field experiences a force B1 (b) (part of) beam deflects B1 α-particles deflect in opposite / different direction to β-particles / electrons or all α-particles have similar deflections or α- particles deflect less B1 γ-rays do not deflect B1

Question Answer Marks 6(a) To produce an alternating/changing magnetic field 1 so that current/voltage is induced (continuously) in the secondary coil OR secondary circuit 1 (b)(i) Ns ÷ Np = Vs ÷ Vp in any form OR (Ns =) Np × Vs ÷ Vp OR 8000 × 6 ÷ 240 1 200 1 (b)(ii) IpVp = IsVs in any form OR (Ip =) Is × Vs ÷ Vp OR 2.0 × 6 ÷ 240 1 0.050 A 1 (b)(iii) (Number of lamps =) 2 ÷ 0.05 = 40 1

Question Answer Marks 7(a) radiation that is always present or due to environment or in everyday life B1 soil  / rocks / earth / cosmic rays / space / Sun / weapons testing / radon / nuclear waste B1 (b)(i) alpha-emission (only) B1 alpha-particles do not penetrate (two sheets of) p aper or β-particles and γ-rays pass through (two sheets of) paper B1 (b)(ii) Po଼ସ ଶ ସ / Heଶ ସ B1 204Pb... or 82Pb C1 204 82Pb A1

© UCLES 2018 Page 6 of 9 Question Answer Marks 8(a)(i) Refraction OR reflection 1 (a)(ii) If refraction in (i) Change or increase or decrease in speed of wave OR change of refractive index OR 1 If reflection in (i) Mention of surface or boundary (1) (b)(i) 2 points both labelled F at 3.5 cm either side of optical centre of lens 1 (b)(ii) Any two of: Paraxial ray from tip of O refracted through farther F/3.5 cm Undeviated ray from tip of O through optical centre of lens Ray from tip of O through nearer F refracted paraxially 2 Image/I drawn from intersection of rays to principal axis with indication t hat image is inverted 1 (b)(iii) In range 3.6 to 4.1 cm 1 (b)(iv) (Image is) real and inverted and diminished 3

speed increases as wavelength increases from 10 to 400 m At 4000 m depth, first wave to reach ship has wavelength 600 m and speed 30.6 m/s. Time taken is 2 000 000 / 30.6 = 65360 s = 18 hours This wave takes 22 hours to reach the ship, hence the speed of the wave is 2 000 000 / (22 x 3600) = 25.2 m/s Checking the table, the wave should have a wavelength 400 m since the period of the wave is 19.6 s, the ship is going to move up and down once every 20 seconds frequency = wave speed / wave length = 30.6 / 600 = 0.051 Hz when the frequency increases, the ship will oscillate up and down more times in the same time Q9 as wavelength increases, speed reaches a maximum of 9.9 m/s in shallow waters speed can continue to increase further to 30 m/s in deep waters

Question Answer Marks 10(a) it / velocity / speed changes / increases (with time) C1 it  / velocity / speed increases at constant rate / steadily A1 (b) any three from: • (initial) acceleration caused by weight / force of gravity • acceleration decreases • drag / resistance force increases (with speed) • (finally / at terminal velocity) no acceleration / constant speed • (finally / at terminal velocity) no resultant force B3 (c)(i) (GPE =) mg (Δ) h (in any form) or 0.0021 × 10 × 0.80 or 2.1 × 10 × 0.80 or 17 (J) C1 0.017  J A1 (c)(ii) (KE =) 1 2  mv 2 (in any form) C1 1 2 × 0.0021 × 1.22 or 1 2 × 2.1 × 1.22 or 1.5 (J) C1 1.5 × 10–3 J A1 (c)(iii) (work done against) friction / drag / resistance or thermal energy generated or (displaced) liquid gains gravitational potential energy B1