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6 marksParticulate Nature of Electromagnetic Radiation

CAPE Physics Unit 2 · May/June 2026 · Paper 2 · Question 3(b)(vi)

The photosensitive emitting plate is a polished copper surface of work function 4.7 eV. The plate is illuminated with ultraviolet light of wavelength 100 nm.

Calculate the slope of the graph in (b) (ii) and use it to determine a value for Planck's constant.

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Other parts of this question

  1. 3(a)(i)Identify the components labelled A, B, C and state the role of EACH component identified.[6 marks]
  2. 3(a)(ii)Define the term 'stopping potential'.[2 marks]
  3. 3(b)(i)Using the equation f = c/λ, complete Column 3 of Table 2.[2 marks]
  4. 3(b)(ii)On the axes provided in Figure 7 on page 19, plot a graph of stopping potential, V_s, versus frequency, f. Draw the line of best fit through the points.[3 marks]
  5. 3(b)(iii)Use the graph in (b) (ii) to determine the threshold wavelength for the material of the photosensitive emitting plate.[3 marks]
  6. 3(b)(iv)Explain what is meant by the 'work function of a material'.[2 marks]
  7. 3(b)(v)Calculate the maximum velocity of the ejected photoelectrons.[6 marks]

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