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  QUESTION 2 Einkaufen    Was kaufen sie heute?       Beispiel: Romy     2.1 A [ans1]  (1)   2.2 B [ans2]  (1)   2.3 C [ans3]  (1)   2.4 E [ans4]  (1)   2.5 F [ans5]  (1)   2.6 G [ans6]  (1)

1 A wave has amplitude A, period T, and wavelength λ.   Which of the following can be used to calculate the speed of the wave? (1)

*18 The circuit diagram shows three identical resistors and two switches, X and Y. The battery has negligible internal resistance.   See addendum Figure 18.1   Each resistor consists of a wire of diameter 0.181 mm and length 55.0 cm. At room temperature, the resistivity of the wire is 1.10 × 10−6 Ω m.   (a) Show that the resistance of one resistor at room temperature is about 24 Ω. (3)       (b) A student suggests that the maximum power output from the resistors in this circuit will be greater than 12 W. Assess whether the student’s suggestion is correct. (4)       (c) Switch X was open and switch Y was closed.   (i) Calculate the number of conduction electrons passing through the resistor every second immediately after switch Y was closed. (3) (ii) After switch Y had been closed for a few minutes, the power dissipated by the resistor decreased. Explain why. (3)   (Total for question 18 = 13 marks)

4 The diagram shows some of the energy levels of a hydrogen atom.   See addendum Figure 4.1 An excited electron in the level –0.54 eV drops to the level –13.60 eV, resulting in the release of at least one photon.   Which of the following photon energy values could not be produced from this electron transition? (1)

3 Which of the following statements is correct for minimum displacement of the particles in a longitudinal wave? (1)

4 The diagram shows some of the energy levels of a hydrogen atom.   See addendum Figure 4.1 An excited electron in the level –0.54 eV drops to the level –13.60 eV, resulting in the release of at least one photon.   Which of the following photon energy values could not be produced from this electron transition? (1)

13 A student used two sources, A and B, of electromagnetic radiation to investigate the photoelectric effect. Radiation from A has a photon energy of 2.0 eV.   (a) The radiation from B has a wavelength of 280 nm. Show that this radiation has a photon energy of about 4.4 eV. (4)       *(b) The student used the two sources of radiation to investigate the photoelectric effect for two different metals, copper and zinc.   The following statements were made by the student.   See addendum  Paragraph 13.1   Explain the conclusions that can be made from these statements. (6)   (Total for question 13 = 10 marks)

  SECTION B   Answer ALL questions on folio paper.

14 A student used the apparatus shown in Photograph 1 to determine the speed of sound in air.   See addendum Figure 14.1   The student switched on the signal generator. The oscilloscope showed one trace from the signal generator and another trace from the microphone. Initially the peaks of one trace were directly above the troughs of the other trace, as shown in Photograph 2.   See addendum Figure 14.2   The horizontal axis of the oscilloscope screen represents time. The number of milliseconds per division on the horizontal scale is known.   (a) Explain how the apparatus shown in Photograph 1 could be used to determine the speed of sound in air. (5)       (b) The student changed the position of the microphone. The traces on the oscilloscope screen before and after changing the position of the microphone are shown in Photograph 2 and Photograph 3.   See addendum Figure 14.2 & Figure 14.3   Explain what change the student made to the position of the microphone between Photograph 2 and Photograph 3.    (3)   (Total for question 14 = 8 marks)

1.13 Noem twee (two) diere (animals) wat dolfyne eet (eat).    (2)   Druk op die knoppie hieronder om die prentjie oop te maak.