2023 TPSS Phy Prelims Ans

Marking Scheme for 4E 2023 Physics Prelim P1 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 C B D B A B D D D B Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 D D A B C C D D C B Q21 Q22 Q3 Q24 Q25 Q26 Q27 Q28 Q29 Q30 B A D D C C A A D C Q31 Q32 Q33 Q34 Q35 Q36 Q37 Q38 Q39 Q40 D B C C A C B D C A Marking Scheme for 4E 2023 Physics Prelim P2 Section A Qn Answers Mark 1ai  Gradient of the graph [1] 1 1aii 4 min = 240 s [1] (as long as student use this in Any part of the working) **1m only if a is positive (correct value) + t is correct value 2 1b  Displacement of the car [1] *do not accept “distance” 1 1c  At 120 s or 2 min [1] 1 1d Direction = right/opposite direct (B.O.D) [1] **Displacement no penalty if student use t in min **Direction  no mark for “negative direction or backwards” 3 2a 2 2b 2

3a  A point where all the weight appears/considered to act on. [1] 1 3b 2 3c 1 4ai 2 4aii (Prove 01 angle)  Since Angle iAB < angle C [1]  TIR will not occur. [1] 3 4bi  Principal Focus F correctly positioned & Labelled correctly [1]  using one/two OTHER light rays with correct dotted and solid portions with arrow [1]  Completing the existing one ray with correct dotted and solid portions and direction. [1] 3 4bii  Image will be dimmer/less bright OR intensity will be reduced [1] 1 5a 1 5b OR 2 5c  4.0s [1] 1 5d  speed @ Q is lower/decreased or the wave is slower [1]  frequency remains the same/constant [1]  depth of sea @ Q is shallower/decreases [1] 3

6a  Friction between car and air causes electrons to be lost, [1]  Making the car positively charged. **student’s answer must state/display knowledge that the surfaces mentioned is between the car & air. 1 6b Any sensible answer:  Tyres are non-conductors or Tyres act as insulating material between car and ground. [1] 1 6c  Metal strap conducts electrons from the ground to the car [1]  to neutralise the positive charges on the car [1] 2 7a  Reading of Ammeter A1: increases  Reading of Ammeter A2: increases  Reading of Voltmeter V1: no change  Reading of Voltmeter V2: increases (2 correct =1 mark, 3 correct = 2 marks, 4 correct = 3 marks) 3 7b **1 mark for value of I if Rtotal is calculated wrongly 1 8a  The index finger (magnetic field) is perpendicular to middle finger (current) [1]  The direction of the force is perpendicular to the current and the magnetic field lines + The force induced (thumb) on the U frame will be upwards/out of paper. [1]  Causing the U frame to rotate Anti-Clockwise/upwards. [1] 3 8b (OWTTE)  Parallel wires carrying current in the same direction.  Has a stronger magnetic field at its exterior as compared to its interior. OR N-pole on right side & S-pole of left side of each turn OR opposite poles between each turn [1]  This results in a net attractive force [1]  Pushing the coil of wire together/closer. 2 9a 2 9b 2 9c  The transformer has an efficiency of 100%.  No heat loss to the surrou