CAPE Physics Unit 2 · May/June 2025 · Paper 2

29 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)(i)4 marksExplain, in terms of electron movement, how drift velocity occurs in metals.
2. 1(a)(ii)5 marksConsider a cylindrical piece of metal of length, d, cross-sectional area, A, and number density of charges, n. Derive the equation relating current in the metal to the drift velocity of its electrons.
3. 1(a)(iii)4 marksA DC generator supplies a current of 10 A to a load through a distribution line. The distribution line is a solid copper conductor of diameter 2.0 mm. The free electron density in copper at room temperature is 8.5 ×…
4. 1(b)(i)4 marksOn the grid provided in Figure 1 on page 7, plot a graph of voltage drop versus length. Draw the line of best fit through the points.
5. 1(b)(ii)3 marksDetermine the gradient of your graph in (b)(i).
6. 1(b)(iii)3 marksDerive an expression for the gradient in terms of ρ, the resistivity of the wire.
7. 1(b)(iv)2 marksHence, determine ρ, the resistivity of the unknown metal.
8. 1(b)(v)1 markCalculate the power dissipated by the wire during the experiment.
9. 1(b)(vi)3 marksCalculate the energy drawn from the power supply if the experiment runs for a total of 15 minutes.
10. 1(b)(vii)1 markState ONE assumption made about the wire in the experiment.
11. 2(a)(i)1 markUse Figure 2 to determine the Peak value (amplitude) of the waveform.
12. 2(a)(ii)3 marksUse Figure 2 to determine the Frequency of the waveform.
13. 2(a)(iii)2 marksUse Figure 2 to determine the RMS value of the waveform.
14. 2(b)3 marksUse your results from (a) to derive an expression for the waveform in Figure 2 in the form v = v_max sin ωt.
15. 2(c)3 marksOn the graph shown in Figure 2 on page 10, sketch the output voltage for ONE cycle given that there is a volt drop of 0.7 volts across the diode, D, when it is conducting.
16. 2(d)4 marksComplete the circuit in Figure 4 by inserting diodes at D1, D2, D3 and D4, with orientation matching the polarity of the output terminals.
17. 2(e)2 marksOn Figure 4, draw arrows to show the direction of current flow for the first half of the cycle, consistent with the polarity of the output terminals.
18. 2(f)2 marksGiven that the input to the full-wave bridge rectifier in Figure 4 is that shown in Figure 2, determine the amplitude and frequency of the fully rectified wave form, assuming that the diodes are ideal.
19. 2(g)4 marksDescribe 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.
20. 2(h)6 marksState THREE advantages and THREE disadvantages of using an alternating current and high voltages for the transmission and distribution of electrical energy.
21. 3(a)(i)6 marksUse an annotated diagram to describe the Geiger-Marsden α-particle scattering experiment.
22. 3(a)(ii)2 marksUsing the results from this experiment, state the TWO major conclusions regarding the nuclear model of the atom.
23. 3(b)(i)2 marksComplete Column 3 and Column 4 of Table 2.
24. 3(b)(ii)4 marksOn the grid provided in Figure 5 on page 17, plot a graph of ln (A/A₀) versus time, t. Draw the line of best fit through the points.
25. 3(b)(iii)5 marksDetermine the gradient of the graph in (b)(ii) and use it to find the half-life of Technetium-99m.
26. 3(b)(iv)4 marksUse your results from (b)(iii) to calculate the time, t, required for the activity in the patient's body to decrease to one per cent of its value at the time of injection.
27. 3(b)(v)1 markExpress the activity in disintegrations per second when the activity has decayed to one per cent of its initial value.
28. 3(b)(vi)2 marksState TWO properties of radioactive tracers that make them suitable for use in nuclear imaging.
29. 3(c)4 marksTechnetium-99m emits gamma-ray photons of energy 140 keV. Calculate the wavelength of these photons.