Transducers · CAPE Physics Unit 2

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

1. 4(b)(iii)1 mark· CAPE Physics Unit 2 · 2004 · Paper 1Give ONE practical use for the circuit in Figure 4.
2. 6(e)3 marks· CAPE Physics Unit 2 · 2006 · Paper 2The led in the circuit is rated 2.4\text{ V}, 25\text{ mA}. A protective resistor has to be connected in series with it so that it does not burn out. What is the value of this resistance?
3. 2(a)4 marks· CAPE Physics Unit 2 · 2007 · Paper 2Plot a graph of resistance R against temperature θ on the grid provided.
4. 2(b)(i)1 mark· CAPE Physics Unit 2 · 2007 · Paper 2Use your graph to determine the resistance of the thermistor at 75 °C.
5. 6(b)(ii)2 marks· CAPE Physics Unit 2 · 2007 · Paper 2If the current in each illuminated segment is 20 mA, calculate the total current drawn by the display when showing the digit 2.
6. Q201 mark · multiple choice· CAPE Physics Unit 2 · 2012 · Paper 1An example of an INPUT transducer is a
7. 5(b)(ii)a)1 mark· CAPE Physics Unit 2 · 2012 · Paper 2State whether the thermistor RT is hot or cold for logic 1 at input A.
8. 5(b)(ii)b)1 mark· CAPE Physics Unit 2 · 2012 · Paper 2State whether the LDR RL is in light or darkness for logic 1 at input B.
9. 5(b)(ii)2 marks· CAPE Physics Unit 2 · 2013 · Paper 2Justify the need for the light dependent resistor (LDR) in the circuit.
10. 5(b)(iii)2 marks· CAPE Physics Unit 2 · 2013 · Paper 2Describe how a relay functions, stating why this device is necessary in the circuit.
11. Q201 mark · multiple choice· CAPE Physics Unit 2 · 2014 · Paper 1An example of an INPUT transducer is a
12. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1With the LDR in complete darkness, the voltage across it is 10\text{ V}. When fully illuminated, the voltage across it drops to 3\text{ V}. What will be the current in the 2\text{ k}\Omega resistor at that time?…
13. Q261 mark · multiple choice· CAPE Physics Unit 2 · 2015 · Paper 1In the amplifier circuit shown above, the LED comes on when
14. Q201 mark · multiple choice· CAPE Physics Unit 2 · 2016 · Paper 1An example of an INPUT transducer is a
15. Q171 mark · multiple choice· CAPE Physics Unit 2 · 2017 · Paper 1Item 17 refers to the following diagram of a light-dependent resistor (LDR). [Circuit diagram of an LDR connected in series with a 2\text{ k}\Omega resistor across a 10\text{ V} supply] With the LDR in complete…
16. Q291 mark · multiple choice· CAPE Physics Unit 2 · 2018 · Paper 1In the amplifier circuit shown above, the LED comes on when
17. 2(a)4 marks· CAPE Physics Unit 2 · 2018 · Paper 2State the meaning of the acronym LDR, and briefly explain its operation.
18. 2(b)2 marks· CAPE Physics Unit 2 · 2018 · Paper 2Complete Columns 3 and 4 of Table 2 (log₁₀ R and log₁₀ Iᵥ).
19. 2(c)4 marks· CAPE Physics Unit 2 · 2018 · Paper 2On the grid provided in Figure 2, plot a graph of log₁₀ R against log₁₀ Iᵥ and draw the line of best fit through the points.
20. 2(d)3 marks· CAPE Physics Unit 2 · 2018 · Paper 2Use your graph from (c) to find the resistance of the LDR at a luminous intensity of 200 cd.
21. 2(a)3 marks· Physics · Unit 2 Q2 2(a)Briefly explain what is a light dependent resistor (LDR).
22. 2(c)(i)7 marks· Physics · Unit 2 Q2 2(c)(i)Use the graph to determine numerical values for b and R₀.
23. 2(c)(ii)1 mark· Physics · Unit 2 Q2 2(c)(ii)Use the equation given in (c) to determine an expression for R_L in terms of R₀ and I.
24. 2(c)(iii)1 mark· Physics · Unit 2 Q2 2(c)(iii)R_dark is defined as the resistance of the LDR when the light intensity, I ≤ 0.01 lux. Determine the threshold value of R_dark using the equation derived in (c)(ii).
25. 2(c)(iv)3 marks· Physics · Unit 2 Q2 2(c)(iv)Using the graph in Figure 4, determine the threshold value for R_dark.
26. 2(f)2 marks· Physics · Unit 2 Q2 2(f)State ONE example of a practical application of an LDR and briefly describe its operation.