Prelim SAJC (H1) P2 2024 QP

1 SAJC 2024 Prelim / 8867 [Turn Over Class Index Number Name ST. ANDREW’S JUNIOR COLLEGE JC 2 2024 Preliminary Examination PHYSICS, Higher 1 8867/02 Paper 2 Structured Questions 28 August 2024 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and Civics Group in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use a HB pencil for any diagrams or graphs. Do not use staplers, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Section A Answer all questions. Section B Answer any one question The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Section A 1 / 8 2 / 4 3 / 6 4 / 12 5 / 16 6 / 14 Section B 7 / 20 8 / 20 Total / 80

2 SAJC 2024 Prelim / 8867 [Turn Over This question paper consists of 22 printed pages including this page.

3 SAJC 2024 Prelim / 8867 [Turn Over

4 SAJC 2024 Prelim / 8867 [Turn Over Section A Answer all the questions in the spaces provided. 1 (a) A circuit is set up to measure the resistance R of a metal wire. The potential difference (p.d.) V across the wire and the current I in the wire are to be measured. Readings for p.d. V and the corresponding current I are obtained. These are shown in Fig. 1.1. Fig. 1.1 (i) Explain how Fig. 1.1 indicates that the readings are subjected to 1. a systematic uncertainty, ……………………………………………………………………………………………………….. …………………………………………………………………………………………………….[1] 2. random uncertainties. ……………………………………………………………………………………………………….. …………………………………………………………………………………………………….[1] (ii) Use data from Fig. 1.1 to determine R. Explain your working. R = …………………………….. Ω [3]

5 SAJC 2024 Prelim / 8867 [Turn Over (b) In another experiment, a value of resistance R of a wire is determined from the following data: Current I = 0.64  0.01 A and p.d. V = 6.8  0.1 V. Calculate the value of R, together with its uncertainty. Give your answer to an appropriate number of significant figures. R = …………………  ………..……….. Ω [3] 2 Fig 2.1 shows how the gravitational force F acting on a 1 kg mass varies with distance from the centre of the Earth. The radius of the Earth is 6300 km. Fig. 2.1 (a) State Newton’s law of gravitation. ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ……………………………………………………………………………………………………………..[1] F / N 6300 8000 12000 16000 20000 24000 28000 32000 distance / km

6 SAJC 2024 Prelim / 8867 [Turn Over (b) Use Fig. 2.1 to calculate the mean mass of the Earth. mass = ….............................. kg [3] 3 Fig. 3.1 shows two parallel metal plates A and B, each of length 10 cm, at a distance of 4.0 cm apart in a vacuum environment. A proton with speed and charge 1.6 x 10-19 C is emitted from a proton source. The proton travels along a straight path exactly down the middle of the region between the parallel plates when there is no electric field applied between the plates. It then hits a screen where it shows up as a bright spot. Fig. 3.1 (not to scale) proton source proton path 10 cm 4.0 cm screen plate A (higher potential) plate B X

7 SAJC 2024 Prelim / 8867 [Turn Over (lower potential) A uniform electric field is now applied in the region between the plates, where plate A is set at a higher potential. The electric field strength is 1.25 kN C-1 between the plates. (a) Determine the time taken for a proton to travel through the plates. time = ……………………………. s [1] (b) Show that the acceleration on a proton due to the electric field is 1.2 x 10 11 m s -2. Draw on Fig. 3.1, when the proton just enters the electric field region at point X, the direction of this acceleration. acceleration = ……………………………. m s -2 [2] (c) Determine the speed at which the proton emerges from the region of uniform electric field. speed = ……………………………. m s -1 [2] (d) On Fig. 3.1, indicate with a cross (×) where the deflected proton is likely to hit the screen. [1]

8 SAJC 2024 Prelim / 8867 [Turn Over 4 (a) Two charged particles X and Y travelling in the same direction, each with velocity v, enter a uniform magnetic field of flux density B pointing into the plane of the paper in a vacuum. Particles X and Y have the same mass m but different charges qX and qY respectively. The paths of particles X and Y in the magnetic field are shown in Fig. 4.1. The radius of the semi- circular path of particle Y is double that of particle X. Fig. 4.1 (i) Explain why the paths of the charged particles are circular in the magnetic field. ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……[2] (ii) State if the charge of the particles is positive or negative. ……….……….……….……….……….……….……………….……….……….……….……[1] (iii) Calculate the ratio . particles X and Y each with velocity v uniform magnetic field B into plane of paper in a vacuum particle X particle Y

9 SAJC 2024 Prelim / 8867 [Turn Over = ………………………….. [3] (b) Particle X with velocity v now enters another uniform magnetic field region having the same flux density B as before but with air molecules throughout. It moves in a path in the magnetic field as shown in Fig. 4.2. Fig. 4.2 (i) Explain, using any relevant equations, the path of particle X shown in Fig. 4.2. ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……[2] (ii) 1. Show that the expression for the time T taken for one revolution of the path is T = . [2] 2. The tau particle is an elementary particle that has the same charge as an electron but has a mass that is 3000 times that of an electron. The average time that this tau particle can survive before it decays is known to be s. Using the expression in (b)(ii)1, hence explain if particle X in Fig. 4.2 could be a tau particle if B = 1.0 T. uniform magnetic field B into plane of paper in air particle X

10 SAJC 2024 Prelim / 8867 [Turn Over ………….……….……….……….……….……………….……….……….……….……… ………….……….……….……….……….……………….……….……….……….……… ………….……….……….……….……….……………….……….……….……….……[2] 5 (a) The results of the alpha-particle scattering experiment provide evidence for the structure of the atom. Result 1: The vast majority of the alpha -particles pass straight through the metal foil or are deviated by small angles. Result 2: A vey small minority of the alpha-particles is scattered through angles greater than 90o. State what may be inferred (deduced) from: (i) Result 1: ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….……………….……….……….……….……… ……….……….……….……….……….……….………