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4 marksThe p-n Junction Diode

CAPE Physics Unit 2 · 2014 · Paper 2 · Question 2(b)(iii)

The forward bias characteristic I_D vs V_D of a junction diode is modelled by I_D = I_s \exp(V_D / V_T), where V_T = 27\text{ mV} at 30^\circ\text{C}. Experimental values of V_D / V_T and I_D are given in Table 2.

Use your graph to calculate the reverse saturation current for this diode.

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Other parts of this question

  1. 2(a)On the grid provided, draw a fully labelled sketch of the reverse bias I-V characteristic of a typical silicon p-n junction diode.[3 marks]
  2. 2(b)(i)Complete Column 3 of Table 2 by calculating \ln(I_D).[3 marks]
  3. 2(b)(ii)On the grid provided on page 11, draw a graph of \ln(I_D) vs V_D / V_T.[5 marks]

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