CAPE Physics Unit 2 · 2017 · Paper 2

31 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)2 marksComplete Columns 3 and 4 in Table 1 by calculating 1/d in mm⁻¹ and 1/d in m⁻¹.
2. 1(b)4 marksUse the results in Table 1 to plot a graph of capacitance, C (nF), versus 1/d (m⁻¹) on the grid provided in Figure 1, and draw the line of best fit.
3. 1(c)(i)2 marksA capacitor of capacitance 10 nF is constructed using the same materials. Determine from the graph the dielectric thickness required for this 10 nF capacitor.
4. 1(c)(ii)2 marksSketch a graph showing the voltage charging characteristic when the 10 nF capacitor is charged to 200 V.
5. 1(d)(i)1 markState the formula used to calculate the capacitance of a parallel plate capacitor of area A and plate separation d with dielectric constant k.
6. 1(d)(ii)1 markState another term for the dielectric constant, k.
7. 1(e)3 marksCalculate the capacitance of a parallel-plate capacitor constructed from two circular metal plates of radius 15 cm separated by 1.0 mm of dielectric material with dielectric constant 10.
8. 2(a)(i)1 markIdentify the type of op-amp circuit shown in Figure 2.
9. 2(a)(ii)1 markState the equation for the closed loop gain, A_CL (V_out / V_in), of the circuit.
10. 2(b)(i)4 marksComplete Columns 3, 4, and 5 of Table 2, given that A_OL is the open-loop gain of the amplifier.
11. 2(b)(ii)4 marksOn the grid provided in Figure 3, plot a graph of log₁₀ A_OL versus log₁₀ f, and draw a smooth curve through the points.
12. 2(b)(iii)5 marksFrom the graph, determine the frequency response curve and hence find the bandwidth of the circuit when R_2 = 100 kΩ and R_1 = 330 Ω.
13. 3(a)3 marksIdentify the parts or quantities indicated by labels P, Q, and R in Figure 4.
14. 3(b)(i)4 marksDetermine the slope of the graph in SI units.
15. 3(b)(ii)3 marksFormulate the algebraic equation relating stopping potential V_s to incident frequency f using the graph in Figure 5.
16. 3(b)(iii)1 markState what the slope of this graph represents physically.
17. 3(b)(iv)4 marksFrom the graph, determine the threshold wavelength for the unknown metal.
18. 4(a)5 marksWith the aid of suitable diagrams, derive the formula for the equivalent resistance of two resistors, R₁ and R₂, connected in parallel.
19. 4(b)(i)2 marksState Kirchhoff's voltage law.
20. 4(b)(ii)8 marksBy applying Kirchhoff's current law to node X and Kirchhoff's voltage law to loops L₁ and L₂, calculate the current I₂ flowing through the 20 kΩ resistor in the circuit shown in Figure 6.
21. 5(a)3 marksExplain what is meant by a 'semiconductor' and state typical values for its resistivity.
22. 5(b)5 marksWith the aid of diagrams, describe how a depletion layer forms at an unbiased p-n junction, specifying the conditions under which its formation begins and ceases.
23. 5(c)(i)1 markDeduce the value of the output voltage V_out when V_in = 0.5 V.
24. 5(c)(ii)2 marksExplain your answer to part (c)(i).
25. 5(c)(iii)1 markDeduce the value of the output voltage and the diode current when V_in = 2.0 V.
26. 5(c)(iv)3 marksExplain the answer given in part (c)(iii).
27. 6(a)2 marksName the apparatus components labelled U, V, W, X, and Y in Figure 8.
28. 6(b)(i)4 marksOutline the experimental procedure followed during the Millikan oil drop experiment.
29. 6(b)(ii)2 marksState the two major conclusions deduced from Millikan's oil drop experiment.
30. 6(c)4 marksAn oil drop of mass 3.0 × 10⁻¹⁵ kg is held stationary between two horizontal metal plates separated by 1.0 cm with an applied voltage of 350 V. Calculate the number of excess electrons on the droplet.
31. 6(d)3 marksWhen the apparatus is adjusted so that droplets rise at constant speed in air, draw and label a free-body diagram showing all the forces acting on such a droplet.