SSS 4NA Prelim 2022 MS

1 5105/02/SSP/PRELIM/22 SINGAPORE SPORTS SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY 4 NORMAL (ACADEMIC) Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 C B C A C D C B B C Q 1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 B A D B D C C A B D MARK SCHEME

2 5105/02/SSP/PRELIM/22 Section A Answer all the questions in the spaces provided. 1 The diagram shows a silver metal pot filled with water and placed directly above a flame that heats the water until it boils. (a) Describe how heat is transferred throughout the water by convection. When the water near the base of the pot is heated, it expands, beceomes less dense and rises. [1] The cooler, denser water sinks to take its place. [1] Process repeats, setting up convection currents, which heat up all the water in the metal pot. [1] (b) What is the advantage of having a silver-coloured pot when boiling water? Silver surface is a poor radiatorof infra-red radiation. [1]

3 5105/02/SSP/PRELIM/22 2 The diagram shows a transverse wave travelling in air through points A and B. The distance between A and B is 40 cm and wave speed is 3.2 m/s. Determine (a) the wavelength wavelength = 16 cm [1] (b) the amplitude, amplitude = 10 cm [1] (c) the frequency, 16 cm = 0.16 m f = v /  [1] = 3.2 / 0.16 = 20 Hz [1] frequency = ……………………... Hz [2] (d) the time taken for the wave to travel from A to B. t = 40 / 320 = 0.125 s [1] time = ……………………. s [1] 20 cm A B

4 5105/02/SSP/PRELIM/22 3 A circuit is set up as shown. (a) When switch S is opened, (i) calculate the total resistance in the circuit. 80 + 40 = 120  [1] resistance = …………………..  [1] (ii) determine the current flowing through the ammeter. I = V/R = 24 /120 = 0.20 A [1] current = …………….. A [1] (b) Switch S is then closed. (i) Calculate the total resistance in the circuit. (1/40 + 1/60)-1 = 24  [1] 24 + 80 = 104  [1] resistance = ………………  [2] (ii) Will the reading of the ammeter be smaller, greater or the same as that in (a)(ii)? Greater [1] 24 V 80  40  60 

5 5105/02/SSP/PRELIM/22 Section B Answer any two questions from this section in the spaces provided. 4 A box of mass 2.0 kg is pushed horizontally on a rough surface by a 10 N force. The box moves at constant speed. (a) State the magnitude of the frictional force acting on the box. Explain your answer. 10 N [1] The acceleration of the box is 0 m/s2. Hence, resultant force acting on the box = 0 N. [1]