Quelpr
3 marksCapacitors

CAPE Physics Unit 2 · 2014 · Paper 2 · Question 1(b)(ii)

Figure 1 shows a circuit containing two capacitors in series, C_A and C_B = 60\text{ }\mu\text{F}, connected with a switch S, a 300\text{ V} supply, and a 1\text{ M}\Omega resistor with voltage V_R. The voltage across C_B is 100\text{ V}.

Use your results from (b)(i) to calculate the value of the capacitance, C_A.

This question uses a figure or table from the paper — you'll see it when you practise.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 1(a)(i)Define the term 'capacitance'.[1 mark]
  2. 1(a)(ii)State the unit in which capacitance is measured.[1 mark]
  3. 1(a)(iii)Identify the two SI units that comprise the unit for capacitance stated in (a)(ii).[1 mark]
  4. 1(b)(i)Calculate the value of the voltage, V_A, when the switch, S, is in Position 1.[2 marks]
  5. 1(b)(iii)Show that the two capacitors in series in Figure 1 are equivalent to a single capacitor of value 20\text{ }\mu\text{F}.[2 marks]
  6. 1(c)(i)On the grid provided on page 7, plot a graph of V_R against t for these results.[3 marks]
  7. 1(c)(ii)Draw the tangent to the curve at the point where t = 0.[1 mark]
  8. 1(c)(iii)Hence, determine the time constant of the voltage decay.[1 mark]

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