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3 marksCapacitors

CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 2 · Question 1(a)

A capacitor discharges through a resistor with current given by I = I_0 e^{-t/RC}. Using the circuit in Figure 1, data was collected to plot a linear graph.

Write a suitable linear equation and complete the table of t/\text{s}, I/\mu\text{A}, and \ln(I/\mu\text{A}).

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Other parts of this question

  1. 1(b)Plot the required linear graph using the student's results on the provided grid.[5 marks]
  2. 1(c)(i)Use the graph to find the value of the current at time t = 0.[2 marks]
  3. 1(c)(ii)Use the graph to find the time constant for the discharge.[2 marks]
  4. 1(d)(i)On the provided grid, sketch a graph showing how the potential difference across the capacitor varies with time during this discharge.[2 marks]
  5. 1(d)(ii)Write an equation for this voltage change using the actual values for the constants in it.[1 mark]

More practice: the rest of this paper · more Capacitors questions · all CAPE Physics Unit 2 past papers