Quelpr

Alternating Currents · CAPE Physics Unit 2

75 past-paper questions on Alternating Currents, part of AC Theory and Electronics, from every CAPE Physics Unit 2 paper on Quelpr.

Practise Alternating Currents
  1. 4(a)(i)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1Find the amplitude of the current.
  2. 4(a)(ii)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1Find the period of the alternating current.
  3. 4(a)(iii)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1Find the frequency of the alternating current.
  4. 4(b)2 marks· CAPE Physics Unit 2 · 2001 · Paper 1For the waveform represented in Figure 4, write an equation which represents how the alternating current, I, varies with time, t.
  5. 5(b)(i)1 mark· CAPE Physics Unit 2 · 2001 · Paper 1Calculate the current in the transmission cable.
  6. 5(b)(ii)2 marks· CAPE Physics Unit 2 · 2001 · Paper 1Calculate the power lost in the transmission cable.
  7. 5(iii)2 marks· CAPE Physics Unit 2 · 2001 · Paper 1Calculate the percentage power lost in the transmission cable if the voltage was not stepped up.
  8. 6(b)(i)1 mark· CAPE Physics Unit 2 · 2002 · Paper 2Write an equation relating the r.m.s. value and the peak value of an alternating current.
  9. 6(b)(ii)3 marks· CAPE Physics Unit 2 · 2002 · Paper 2A car battery-charger operates from a 120 V r.m.s. a.c. line and supplies 10 A d.c. at 14 V. If it is 80% efficient, calculate the current drawn from the a.c. line.
  10. 6(c)(iii)2 marks· CAPE Physics Unit 2 · 2002 · Paper 2Calculate the current in the transmission supply cable.
  11. 7(a)(i)1 mark· CAPE Physics Unit 2 · 2003 · Paper 2State the relationship between peak voltage, V_p, and root mean square voltage, V_rms, for an alternating sinusoidal voltage.
  12. 7(a)(ii)2 marks· CAPE Physics Unit 2 · 2003 · Paper 2Calculate the value of the direct current that will produce the same quantity of thermal energy in a particular resistor, as an alternating current that has a maximum value of 2.60 A.
  13. 7(c)(ii)5 marks· CAPE Physics Unit 2 · 2003 · Paper 2The average rate of energy consumption in the houses served by the transformer is 78 kW. Calculate the peak value of the current in BOTH windings of the transformer.
  14. 4(b)(ii)1 mark· CAPE Physics Unit 2 · 2005 · Paper 1A signal with voltage V_i given by V_i = 0.2 sin(100 pi t) is applied to the comparator in (b)(i). Calculate the frequency of the signal.
  15. 6(b)(i)2 marks· CAPE Physics Unit 2 · 2005 · Paper 2Calculate the peak value of the primary voltage.
  16. 6(c)4 marks· CAPE Physics Unit 2 · 2005 · Paper 2Calculate what percentage of the power transmitted is lost in the cables.
  17. 6(a)(i)1 mark· CAPE Physics Unit 2 · 2006 · Paper 1Determine the frequency of the signal.
  18. 6(a)(ii)1 mark· CAPE Physics Unit 2 · 2006 · Paper 1Determine the period of the signal.
  19. 6(a)(iii)2 marks· CAPE Physics Unit 2 · 2006 · Paper 1Find the r.m.s. voltage of the signal.
  20. 6(a)(iv)3 marks· CAPE Physics Unit 2 · 2006 · Paper 1Draw the graph showing the variation of voltage with time on the axes in Figure 6.
  21. 7(d)(ii)3 marks· CAPE Physics Unit 2 · 2006 · Paper 2The input terminals X and Y are connected to the secondary coil of an ideal transformer. The primary coil contains 22000 turns and is connected to a 220\text{ V}_{\text{r.m.s.}} alternating supply. The input to the…
  22. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2007 · Paper 1A direct current (I) dissipates power in a resistor (R). A sinusoidal alternating current dissipates the same power in another resistor of one quarter the value. What is the r.m.s. value of the alternating current?
  23. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1A sinusoidal alternating current of a peak value 20\text{ A} dissipates power of 50\text{ W} in a resistor R. The value of the resistor is
  24. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1A direct current of 5\text{ A} dissipates heat in a given resistor at the same rate as a sinusoidal alternating current flowing through the same resistor. What is the root mean square value of the alternating current.
  25. Q191 mark · multiple choice· CAPE Physics Unit 2 · 2007 (Specimen) · Paper 1The ratio of the secondary turns to the primary turns in an ideal transformer is 1 : 30. A 120\text{ V} a.c. supply is connected to the primary coil and a load of 20\ \Omega connected to the secondary coil. What…
  26. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 1If the equation of an a.c voltage is V = 200 \sin 50\pi t, then the r.m.s. value of the voltage is
  27. 4(c)(ii)b)2 marks· CAPE Physics Unit 2 · 2008 (Rest of Region) · Paper 2Find the r.m.s. value of the e.m.f. induced in the coil.
  28. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1Item 17 refers to the following diagram. The r.m.s value of a.c voltage is related to the peak to peak voltage by the equation
  29. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1A sinusoidal alternating current of peak value 50\text{ A} dissipates power (P) in a 2\ \Omega resistor. What is the value of P?
  30. Q201 mark · multiple choice· CAPE Physics Unit 2 · 2008 (T&T) · Paper 1Item 20 refers to the following graph which represents a sinusoidal alternating current against time as drawn below. The equation to represent this alternating current is
  31. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1The effective value of a sinusoidal alternating curve with a peak current, I_0, is
  32. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1Item 17 refers to the following graph which represents a sinusoidal alternating current against time. The equation to represent this alternating current is
  33. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2009 · Paper 1Why is it advantageous to use an alternating current instead of a steady d.c. when transmitting electrical energy at high voltages?
  34. 5(c)(i)1 mark· CAPE Physics Unit 2 · 2009 · Paper 2Determine the frequency of this input signal.
  35. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1A.C. may be represented by the following equation. I = I_0 \sin \omega t. I_0 is
  36. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1The equation to represent the alternating current is
  37. Q201 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1A sinusoidal signal has a peak voltage of 5.0\text{ V}. What is the r.m.s value of this signal?
  38. Q391 mark · multiple choice· CAPE Physics Unit 2 · 2010 · Paper 1Which of the following statements is true?
  39. Q141 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1An ideal transformer has 600 turns in the primary winding and 40 turns in the secondary winding. If the current in the primary winding is 5\text{ A}, and the primary voltage is 120\text{ V}, what is the current and…
  40. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1What is the V_{\text{r.m.s}} of a wave form with a peak to peak voltage of 40\text{ V}?
  41. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2011 · Paper 1The equation which represents this alternating current is
  42. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1A.C. may be represented by the following equation, I = I_0 \sin \omega t. I_0 is
  43. Q391 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1Which of the following statements is true?
  44. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1A.C. may be represented by the equation, I = I_0 \sin \omega t. I_0 is
  45. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1The equation which represents this alternating current is
  46. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1A sinusoidal signal has a peak voltage of 5.0\text{ V}. What is the r.m.s value of this signal?
  47. Q351 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1What is the de Broglie wavelength of an olympic sprinter of mass 60\text{ kg} when running at a speed of 10\text{ m s}^{-1}?
  48. Q371 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1Each of the following particles is moving at 0.2c, where c is the speed of electromagnetic radiation. Which particle has the longest de Broglie wavelength associated with it?
  49. Q401 mark · multiple choice· CAPE Physics Unit 2 · 2013 · Paper 1Which of the following statements is true?
  50. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1AC current may be represented by the equation, I = I_0 \sin \omega t. What term describes the quantity I_0?
  51. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1The effective value of a sinusoidal alternating curve with a peak current, I_0, is
  52. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1In the equation I = I_0 \sin \omega t for an alternating current, the symbol I_0 represents the
  53. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1A sinusoidal signal has a peak voltage of 5.0\text{ V}. What is the root mean square value of this signal?
  54. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1Which of the following equations represents an alternating voltage?
  55. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1The peak potential difference of a certain a.c. supply is 24\text{ V}. What is the root mean square (r.m.s.) value?
  56. 5(b)(i)1 mark· CAPE Physics Unit 2 · 2016 · Paper 2Determine the peak voltage.
  57. 5(b)(ii)2 marks· CAPE Physics Unit 2 · 2016 · Paper 2Determine the frequency.
  58. 5(b)(iii)2 marks· CAPE Physics Unit 2 · 2016 · Paper 2Determine the root mean square (rms) voltage.
  59. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1What is the r.m.s value of a sinusoidal signal of peak value 3.0\text{ V}?
  60. Q381 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1Which of the following scientists suggested that matter had a dual nature and proposed that any particle of a specific momentum had an associated wavelength?
  61. Q31 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1An alternating current is represented by the equation I = I_0 \sin 120\pi t where t has units of seconds. How many complete cycles does it go through in 10\text{ minutes}?
  62. Q161 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1Which of the following equations represents an alternating voltage?
  63. Q181 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1A sinusoidal signal has a peak voltage of 5.0\text{ V}. What is the root mean square value of this signal?
  64. Q311 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1Each of the following particles is moving at 0.2\ c, where c is the speed of electromagnetic radiation. Which particle has the LONGEST de Broglie wavelength associated with it?
  65. Q361 mark · multiple choice· CAPE Physics Unit 2 · 2019 · Paper 1What is the de Broglie wavelength of an Olympic sprinter of mass 60\text{ kg} when running at a speed of 10\text{ m s}^{-1}?
  66. 2(a)8 marks· Physics · Unit 2 Q2 2(a)State the meaning of EACH symbol in the table below and use Figure 2 to determine each value.
  67. 2(a)4 marks· Physics · Unit 2 Q2 2(a)Derive an expression for the current waveform, in the form I = I_p sin(ωt), when the device is operating at its rated current.
  68. 2(a)(i)1 mark· Physics · Unit 2 Q2 2(a)(i)Use Figure 2 to determine the Peak value (amplitude) of the waveform.
  69. 2(a)(ii)3 marks· Physics · Unit 2 Q2 2(a)(ii)Use Figure 2 to determine the Frequency of the waveform.
  70. 2(a)(iii)2 marks· Physics · Unit 2 Q2 2(a)(iii)Use Figure 2 to determine the RMS value of the waveform.
  71. 2(b)5 marks· Physics · Unit 2 Q2 2(b)Calculate the power dissipated in the circuit in Figure 3.
  72. 2(b)7 marks· Physics · Unit 2 Q2 2(b)Sketch a graph of ONE cycle of the current waveform in (a), with axes labelled to show the values of the period and amplitude.
  73. 2(b)3 marks· Physics · Unit 2 Q2 2(b)Use your results from (a) to derive an expression for the waveform in Figure 2 in the form v = v_max sin ωt.
  74. 2(g)4 marks· Physics · Unit 2 Q2 2(g)Describe the procedure for an experiment that can be used to verify the relationship between the peak value of an alternating current and the equivalent direct current.
  75. 2(h)6 marks· Physics · Unit 2 Q2 2(h)State THREE advantages and THREE disadvantages of using an alternating current and high voltages for the transmission and distribution of electrical energy.

Related topics in AC Theory and Electronics