2022 XMS P1 AND P2 PRELIM MS

1 Created by Mr. Zhuang HY 4E Prelim 2022 Physics Paper 1 (40 marks) 1 2 3 4 5 6 7 8 9 10 D D B B A C A C D A 11 12 13 14 15 16 17 18 19 20 D B B C D C C A B A 21 22 23 24 25 26 27 28 29 30 A B B C A D C B B A 31 32 33 34 35 36 37 38 39 40 B D A D D B C C B D Paper 2 Section A (50 marks) 1a External diameter = 9.67 cm [1] Internal diameter = 8.18 cm [1] [2] 1b Density is the mass per unit volume of a substance. *Do NOT accept formula as the answer. [1] 1c 3 700 1.54 9.67()32 m V  = =  g cm-3 (2 or 3 s.f) [2] Since the density of the hollow spherical capsule is more than the density of water, it will sink. [1] Working [1] Ans [1] Explain [1] Total [6] 2a As the air is released from the can, the number of air molecules within the can decreases. [1] The frequency of collisions between the air molecules and the walls of the can decreases [1], thus reducing the average force per unit area exerted on the walls of the can [1], causing pressure to decrease. [3] 2b 4 552 1 1 2 2 1 2 4 1 9.4 10(1.0 10 )( ) 5.2 101.8 10 VPV P V P P V − − = → = =     Pa (2 or 3 s.f) Working [1] Ans [1] Total [5]

2 Created by Mr. Zhuang HY 3ai It is the distance between the principal focus and the optical centre of the converging lens. [1] 3aii [1] for correct position and labelling of lens [1] for correct position and labelling of focal point [1] for all three correct light rays [3] 3bi [1] for correct normal and marking of angle of incidence [1] for correct light ray in the lens and exiting the lens [2] 3bii The larger the refractive index, the smaller the focal length. [1] A larger refractive index will cause the light ray to bend more towards the normal as it enters the lens and will bend further away from the normal as it exits the lens , this causing the light ray to cut the principal axis closer to its optical centre. [1] [2] Total [8] 4a The centre of gravity of an object is defined as the point through which its whole weight appears to act for any orientation of the object. [1] lens F i

3 Created by Mr. Zhuang HY 4b Taking moments about his feet, Sum of CW moments = Sum of ACW moments 850 (1.10) (0.50 1.10)F =  + 850 1.10 5801.60F = N (2 or 3 s.f) Working [1] Ans [1] Total [3] 5a Temperature is the measure of the hotness and coldness of a body. OR Temperature is a measure of the average kinetic energy of the particles in the body. [1] 5b 1. The darker the colour of the body, the higher the rate of thermal radiation. 2. The duller the surface of the body, the higher the rate of thermal radiation. 3. The larger the surface area of the object, the higher the rate of thermal radiation. 4. The higher the surface temperature of the surface of the object relative to the surrounding, the higher the rate of thermal radiation. *Any 2, [1] each [2] 5c Rate of heat loss by chamber and a monkey = t cm w aterw ater  = 3600 )2532(42000.3 − = 24.5 W [1] Rate of heat loss by chamber and 2 monkeys = t cm w aterw ater  = 3600 )2532(42000.7 − ≈ 57.17 W [1] Rate of loss of thermal energy of the 2nd monkey = 57.17 – 24.5 ≈ 33 W [2] (2 or 3 s.f) Working [3] Ans [1] Total [7]

4 Created by Mr. Zhuang HY 6a 502.0 1.0100vf = →  = m s-1 1.0 0.060 0.060dv d v tt= → =  =  = m (2 or 3 s.f) Working [1] Ans [1] 6b [1] Total [3] 7a Visible light [1] 7b Sunbeds for artificial tanning Sterilisation of medical equipment Forgery detection *Any one, list not exhaustive [1] 7c 8 12 6 3.0 10 3.0 10100 10 vv f f   − = → = = =   Hz (2 or 3 s.f) Working & Ans [1] 7d Electromagnetic waves can travel through vacuum but sound waves cannot. OR Electromagnetic waves are transverse waves but sound waves are longitudinal waves. [1] Total [4] 8a Electric field is a region where an electric charge experiences an electric force. [1]

5 Created by Mr. Zhuang HY 8bi [1] for correct shape [1] for correct direction [2] 8bii [1] Total [4] 9a P: South pole Q: North pole *Both correct to get [1], [0] otherwise. [1] 9b Bar A: Magnetised [1] Like poles repel. This will imply that bar A must a magnet. [1] Bar B: Undetermined [1] Attraction can happen between two unlike poles, or between a magnet and an unmagnetised magnetic material. [1] [4] Total [5] 10a The e.m.f source will last longer. [1] +100 V -100 V +100 V -100 V

6 Created by Mr. Zhuang HY 10bi 12 1 1 1 1 1 1 0.73 3.0TXR R R R= + → = + 1 1 1 0.964 0.960.73 3.0 X X RR = − →   Ω (2 or 3 s.f) Working [1] Ans [1] 10bii 0.73 2.0 0.53482.0 0.73 XV =  + V 0.5348 0.550.964 X X X VI R= =  A (2 or 3 s.f) Working [1] Ans [1] Total [5] Paper 2 Section B (30 marks) 11a = → = = = 7100 17.75 18400 PP VI I V A (2 or 3 s.f) Working [1] Ans [1] 11bi Total mass = +=610 70 680 kg Total weight = =680 10 6800 N Taking upwards as positive, = + =RF T W ma + − =  → = + = ( 6800) 680 0.61 414.8 6800 7214.8 7200TT N (2 or 3 s.f) Working [1] Ans [1] 11bii Weight of passenger = 70 10 700mg=  = N Taking upwards as positive, = + =RF N W ma ( 700) 70 0.61 42.7 700 742.7 740NN+ − =  → = + =  N (2 or 3 s.f) Working [1] Ans [1] 11c −−= → =( ) ( 0) 0.61 2.6 v u va t =  = 0.61 2.6 1.586 1.6v m s-1 (2 or 3 s.f) Working [1] Ans [1] 11d Total energy supplied =  =  =7100 14 99400Pt J [1] Useful energy supplied to lift = 21 2mgh mv+ = 21(680 10 13) ( 680 1.586 ) 892552  +    Efficiency = 89255 100 90%99400 (2 or 3 s.f) Working [2] Ans [1] Total [11]

7 Created by Mr. Zhuang HY 12ai Energy can neither be created nor destroyed. It can only be converted from on form to another, or transferred from one body to another, with the total amount remaining constant. [1] 12aii GPE at A 490 10 30 147000 150000mgh= =   =  J (2 or 3 s.f) Working [1] Ans [1] 12aiii KE at C = 2211 490 10 2450022mv =   = J [1] GPE at C = 490 10 10 49000mgh=   = J W.d aginst friction = 147000 – 24500 – 49000 = 73500 ≈ 74000 J (2 or 3 s.f) [2] Working [2] Ans [1] 12bi * Correct arrow and label must be present to get [1]. [1] 12c Incorrect. [1] Due to inertia, the children will continue to move forward as the carriage turns left, thus causing the children to be closer to the right side of the carriage. [1] [2] Total [10] EITHER 13a 7.18.1 3 =f Hz (2 or 3 s.f) Working [1] Ans [1] 13b 10 mm [1] 13ci A magnetic field is created around the coil as the coil is switched on. [1] As the copper plate, an electrical conductor, oscillates, it cuts the magnetic field of the coil. [1] According to Faraday’s law of electromagnetic induction, an induced e.m.f will be created across the copper plate, thus creating induced eddy current in the copper plate. [1] [5] v

8 Created by Mr. Zhuang HY According to Lenz’s law, the induced eddy current will create a magnetic field to oppose the change producing itself.[1] This will create a resistive force that will dampen the oscillation of the copper plate, thereby reducing the amplitude of oscillations. [1] 13cii As the amplitude decreases, the copper plate will cut the magnetic field of the coil at a lower rate. [1] This will result in a lower resistive force created to dampen the oscillation. [1] [2] Total [10] OR 13a If wire B instead of wire A is connected to the live terminal , the light bulb will be still connected to the high potential even if the switch is opened. [1] If the bulb is faulty, the user, who is at a lower potential, will get electrocuted if he or she touched the faulty light bulb which is at high potential. [1] [2] 13bi The fuse is to prevent a current surge (current that is larger than the operating current) from damaging the table lamp. [1] If the current is larger than the fuse’s rating, the heat generated by the large current [1] will melt the connect