PLS 2022 EOY 4NA Science Physics MS

2022 MYE 4NA Science (Physics) Answer 1 B 11 A 2 B 12 B 3 A 13 B 4 D 14 D 5 B 15 D 6 D 16 C 7 C 17 C 8 B 18 A 9 A 19 D 10 C 20 A Section A 1 (a) 𝜇 1 (b) 60 000 1 (c) tavg for 20 oscillations = (35.26 + 36.23 + 34.83 + 34.94 + 36.02)/5 = 35.456 s period = 35.456/20 = 1.77 s (3 s.f.) 1 1 2 (a) 1 / 20 = 0.05 s 0.05 x 6 = 0.3 s 1 1 (b) v = (0.6)/(2 x 0.05) = 6.0 m/s 1 (c) accelerates/increasing velocity 1 3 (a) 80 F = 20 x 42 F = 10.5 N 1 (b) 42 ÷ 100 = 0.42 N/kg 1 (c) 0.42 x 300 = 126 N 1 (d) Work is needed to compress the air. 4 wire colour of insulation earth Yellow and green live Brown neutral blue 2 marks for 3 correct. 1 mark for 2 correct. Section B 5 (a) convection 1 (b) Water near the coil is cooled, contracts, become denser and sink, displacing the water below. The water below, being less dense, rises and is cooled by the coil. The process repeats and convection current is formed below the coil. 1 1 1 (c) Internal energy decreases as temperature of the water 1 and hence the internal kinetic energy decreases. 1 (e) The graph will be less steep. As rate of heat transfer decreases since plastic is a poor conductor of heat. 1 1 6 (a) (i) 5 m (ii) 1 s (iii) 5 m/s (iv) 2 m 1 1 1 1 (b) FFTTTFFF 1 for every 2 correct 7 (a) (1/6+1/3)-1 = 2 R = 7 + 2 + 6 = 15 Ω 1 1 1 (b) I=12/15=0.8 A 1 (c) V=0.8 x 7 =5.6V 1 (d) VW = 0.8 x 6 = 4.8 VX = 12 – 5.6 – 4.8 = 1.6 V P = V2/R = 1.62/6 = 0.427 W 1 1 (e) E=0.42667 x 60 = 25.6 J 1