CSEC Physics · 1995 · Paper 2

28 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 marksState Archimedes' principle.
2. 1(b)(i)3 marksCalculate the mass of air inside the balloon.
3. 1(b)(ii)2 marksDetermine the total weight, in newtons, of the material, load and air. (g = 10 N kg⁻¹)
4. 1(b)(iii)3 marksThe balloon remains stationary about 100 m above the ground. State what forces are acting on the balloon, and explain how they result in no motion.
5. 1(b)(iv)2 marksIf the density of the air outside the balloon is 1.3 kg m⁻³, calculate the weight of the air which is displaced by the balloon.
6. 1(b)(v)2 marksExplain why the balloon begins to rise when the air is heated to a higher temperature.
7. 2(a)(i)1 markThe atomic number of chlorine (Cl) is 17. How many protons are there in one atom of silicon (Si)?
8. 2(a)(ii)4 marksThe most common isotope of boron (B) may be represented as ¹¹₅B. A boron atom has two shells of electrons, with two electrons in the first shell. In the space provided, draw a clear diagram to represent the number and…
9. 2(a)(iii)1 markWrite the symbol for another possible isotope of boron.
10. 2(b)(i)4 marksBy reading off values of the count rate at suitable times, show that the half-life of Sample A is constant, and find its value.
11. 2(b)(ii)1 markBy considering the relevant graph, comment on the half-life of Sample B.
12. 2(b)(iii)1 markWhy are the points on the graph of Sample B not exactly on the line even though the ratemeter was not faulty?
13. 2(b)(iv)1 markWhat difference, if any, would be noticed in the graph if Sample B were heated?
14. 2(b)(v)3 marksSample B is an isotope of thorium (Th), with a proton number of 90 and a neutron number of 142. It decays by the emission of an alpha particle to form radium (Ra). Write a nuclear reaction to represent this decay.
15. 3(a)(i)3 marksExplain how the thermostat works.
16. 3(a)(ii)2 marksWhat would be the effect on the working of the thermostat if the bi-metallic strip were inserted with the iron uppermost?
17. 3(b)(i)4 marksWhat is the cost per year of the operation of the water-heater if one kilowatt-hour costs 40 cents?
18. 3(b)(ii)2 marksTo save money, the family considers installing a solar water-heater costing $4 400. How many years must pass before the cost of the solar heater is equal to the cost of the electrical energy saved (the "pay-back time")?
19. 3(c)3 marksOne of the reasons for having a glass cover over the collector plate of the solar water-heater, shown in Figure 4, is to take advantage of the glass-house (or green-house) effect. Explain the glass-house effect.
20. 4(a)(i)2 marksThe wire is moved up and down.
21. 4(a)(ii)1 markThe wire is moved up and down faster.
22. 4(a)(iii)1 markThe wire is moved from pole to pole horizontally.
23. 4(a)(iv)1 markThe magnet poles are moved up and down with the wire stationary.
24. 4(b)(i)1 markis closed
25. 4(b)(ii)1 markremains closed
26. 4(b)(iii)1 markis opened.
27. 4(c)(i)5 marksThe symbol for a transformer is shown. Complete the circuit diagram to show how a transformer, together with the components listed below, could be used to charge a 12 V car battery from a 120 V mains supply. Components:…
28. 4(c)(ii)3 marksThe potential difference from the secondary coil of such a transformer is 18 V, and the charging current through the 12 V battery is 2 A. What is the value of the variable resistance?