EJC 2023 J2 H2 PRELIM P3

©EJC 2023 9749/J2H2PRELIM/2023 [Turn over EUNOIA JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATIONS 2023 General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CIVICS GROUP 2 2 - REGISTRATION NUMBER PHYSICS Longer Structured Questions 9749/03 19th September 2023 2 hours READ THESE INSTRUCTIONS FIRST Write your name, civics group and registration number on all the work you hand in. The use of an approved scientific calculator is expected where appropriate. Section A Answer all questions. Section B Answer one question only. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use paper clips, highlighters, glue or correction fluid. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 26 printed pages and 2 blank pages. For Examiner’s Use Section A Q1 14 Q2 10 Q3 9 Q4 17 Q5 10 Section B Q6 20 Q7 20 s.f. P3 Total 80

2 ©EJC 2023 9749/J2H2PRELIM/2023 Data speed of light in free space, ( )( ) 81 71 0 12 1 0 91 19 34 27 31 e 27 p 11 23 1 A 23 1 10 m s 10 H m 10 F m 10 F m 10 C 6 63 10 J s 1 3 00 4 8 85 1 36 1 60 9 11 1 67 66 10 kg 10 kg 10 kg J K mol 6 02 10 8 31 1 38 mol 10 J K c. . / e h. u. m m . . . R. N k . . G    − −− −− −− − − − − − −− − −−      = = = =   = = = = = = = =  11 2 2 2 10 N m kg m 67 81 s 6 9 . g. −− − = =  permeability of free space, permittivity of free space, elementary charge, the Planck constant, unified atomic mass constant, rest mass of electron, rest mass of proton, molar gas constant, the Avogadro constant, the Boltzmann constant, gravitational constant, acceleration of free fall,

3 ©EJC 2023 9749/J2H2PRELIM/2023 [Turn over Formulae uniformly accelerated motion, ( ) ( ) 2 22 2 0 0 22 0 12 12 0 0 0 0 0 0 1 2 1 2 2 / K / C 273 15 1 3 3 2 sin cos 1 1 1 4 sin 2 2 exp ln2 at u as V p gh Gm r T T . Nmpc V kT x x t v v t xx R / R / R / R QV r x x t B d NB r s ut v Wp t E Bn t Anvq RR xx              =+  = =− =  + = = = = − ++ = + + = = = = = − = =+ = = = = = I I I I work done on/by a gas, hydrostatic pressure, gravitational potential, temperature, pressure of an ideal gas, mean translational kinetic energy of an ideal gas molecule displacement of particle in s.h.m. velocity of particle in s.h.m. electric current, resistors in series, resistors in parallel, electric potential, alternating current/voltage, magnetic flux density due to a long straight wire magnetic flux density due to a flat circular coil magnetic flux density due to a long solenoid radioactive decay, decay constant

4 ©EJC 2023 9749/J2H2PRELIM/2023 Section A Answer all the questions in this section in the spaces provided. 1 (a) Three sheets of polaroids P, Q and R are placed close to one another. Polaroids P and R have their polarising axes fixed and perpendicular to each other. The incoming beam of intensity Io is polarised parallel to the polarising axis of P before reaching P. Polaroid Q is rotated about the axis of the light beam, as shown in Fig. 1.1. The plane of Polaroid Q remains parallel to that of P and R. Complete Fig. 1.2 to show the variation of the angle of rotation with intensity of the light transmitted after passing Polaroid R. [2] 45 90 135 180 angle of rotation/  0 intensity of transmitted light Fig. 1.2 Fig. 1.1 polaroid R Io

5 ©EJC 2023 9749/J2H2PRELIM/2023 [Turn over (b) A parallel beam of wavelength 600 nm is incident normally on a diffraction grating. Fig. 1.3 shows part of the diffraction grating used. Fig. 1.3 (i) Determine the distance between adjacent slits on the grating. distance = ……………………………. m [2] 10 m

6 ©EJC 2023 9749/J2H2PRELIM/2023 (ii) Fig 1.4 shows how the parallel beam of light that was incident on the diffraction grating. Fig. 1.4 Calculate the total number of images that emerge from the grating within the shaded 90 region shown in Fig. 1.4. total number of images = ………………………… [2] (iii) In a mass production of diffraction gratings with slit separation d, a monochromatic laser light with a fixed wavelength 𝜆 was used to check for the quality of the diffraction gratings produced. In a certain test, a few defective pieces were found. In a good product, the first order maximum occurs at an angle of 𝛼 from the zeroth order maximum. In a defective product, the first order maximum is not a single sharp point but a band of light extending from angle 𝛼 to 𝛽, where 𝛽 is larger than 𝛼. The band of light is brightest at an angle of 𝛼 and reduces towards the angle of 𝛽. Describe what could be the fault in the manufacturing of the grating to result in this observation. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. …………………………………………………………………………………………………….. ……………………………………………………………………………………………..….. [2]

7 ©EJC 2023 9749/J2H2PRELIM/2023 [Turn over (c) On an initially calm day out at sea, water waves of constant speed approach a sea wall and a stationary wave is formed. (i) State how the stationary wave is formed. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. ……………………………………………………………………………………………………….. …………………………………………………………………………………………….….….. [2] (ii) When the waves hit the wall, an increase in amplitude of the wave was observed at the sea wall. State and explain if the water waves experienced a phase change when hitting the wall to result in the increase in amplitude. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… …………………………………………………………………………………………………... [2] (iii) In Fig. 1.5, fine sand is spread along the length of a tube fitted with a piston. A small loudspeaker which emits sound of 72 0 Hz is placed at the opened end and the length of the air column was varied by adjusting the position of the piston. When the air column is 0.78 m, the sand in the tube forms the pattern as shown. Calculate the speed of sound travelling through the air column. speed of sound = ……………………………. m s−1 [2] [Total: 14] Fig. 1.5 0.78 m

8 ©EJC 2023 9749/J2H2PRELIM/2023 2 (a) (i) State the first law of thermodynamics. …………………………………………………………………………………………………... …………………………………………………………………………………………………... ……………………………………………………………………………………………..…[2] (ii) Use first law of thermodynamics to explain how roasting of potatoes causes its temperature to rise. ………………………………………………………………………………………………….... ………………………………………………………………………………………………….... ………………………………………………………………………………………………….... ………………………………………………………………………………………………….... ………………………………………………………………………………………………….... ………………………………………………………………………………………………….... …………………………………………………………………………………………………[3]

9 ©EJC 2023 9749/J2H2PRELIM/2023 [Turn over (b) An ideal gas undergoes a cycle of changes A → B → C → A as shown in Fig. 2.1. Process A to B takes place at constant temperature of 310 K. Process B to C takes place at constant volume and during this process, 55 J of heat leaves the system. T he temperature at C is 280 K. Process C to A takes place with no heat exchange. Fig. 2.1 (i) Calculate the change in internal energy of the gas during the process B to C. change in internal energy = ……………………… J [2] (ii) Determine the work done by the gas during the process C to A. Explain your working cl