CAPE Physics Unit 2 · May/June 2023 · Paper 2

27 questions and parts from this paper. Open one to see it in full, then practise it on Quelpr and get it marked against the mark scheme.

1. 1(a)10 marksUsing conventional symbols for physical quantities, complete Column 2 and Column 3 of Table 1.
2. 1(b)(i)3 marksDetermine the magnitude of the electric field between the plates.
3. 1(b)(ii)4 marksHence, calculate the vertical acceleration of the electrons as they pass between the plates.
4. 1(c)(i)4 marksComplete Row 2 and Row 3 of Table 2.
5. 1(c)(ii)4 marksOn the grid provided in Figure 2 on page 9, plot a graph of negative vertical displacement versus time for the electron motion between the plates. Draw the best smooth curve through the points.
6. 1(c)(iii)1 markThe electrons traverse the field in 3.75 nanoseconds. Use the graph in (c) (ii) to determine how far from the horizontal axis of the plates the beam will emerge, as it exits the space between the plates.
7. 1(d)4 marksCalculate the vertical velocity of the electron beam and hence its direction of travel on emerging from between the plates.
8. 2(a)(i)1 markWrite an equation to show the relationship between the output voltage, V_out, and the inputs, V1 and V2.
9. 2(a)(ii)3 marksUsing the equation in (a) (i), briefly explain how a comparator works.
10. 2(a)(iii)2 marksThe amplifier in Figure 3 on page 10, has a gain, A = 10^6, and is powered by a supply voltage, V_s, of ± 5 V. Determine the differential input voltage, ΔV, that will result in saturation with a negative voltage on the…
11. 2(b)8 marksExplain how the circuit in Figure 4 will function to trigger the alarm if the temperature drops below the threshold value.
12. 2(c)8 marksDetermine the overall voltage gain of the circuit.
13. 2(d)1 markState what is meant by the 'bandwidth of an operational amplifier'.
14. 2(e)(i)4 marksOn Figure 6, insert EACH of the following labels: f_c and f_u. State the numerical value of the frequency at EACH point on the graph. Cut-off frequency, f_c Unity-gain frequency, f_u
15. 2(e)(ii)3 marksDetermine the gain of the amplifier at 1 kHz.
16. 3(a)(i)2 marksDefine EACH of the following terms. Work function
17. 3(a)(ii)1 markThreshold frequency
18. 3(a)(iii)1 markCut-off wavelength
19. 3(b)4 marksWith reference to the apparatus in Figure 7, explain the meaning of the term 'stopping potential'.
20. 3(c)(i)2 marksWrite the general form of the photoelectric equation and rearrange it to show the linear relationship between stopping potential, V_s, and frequency, f, as shown on the graph in Figure 8.
21. 3(c)(ii)3 marksDetermine the gradient of the line in Figure 8.
22. 3(c)(iii)3 marksDetermine the percentage difference between the experimental value of h/e obtained in (c) (ii) and the calculated theoretical value of h/e (using the standard values of h and e given in the answer booklet on page 4).
23. 3(c)(iv)2 marksComment on the result obtained in (c) (iii).
24. 3(c)(v)5 marksExtrapolate the line on the graph in Figure 8 on page 19, to find the intercept on the V_s axis and use this value to determine the work function of the cathode material, in joules.
25. 3(d)(i)2 marksFor EACH of the labelled regions on the graph in Figure 9, state what happens to the flow of the photocurrent and explain why this happens in EACH case. Region A
26. 3(d)(ii)2 marksRegion B
27. 3(d)(iii)3 marksRegion C