CSEC Physics Paper 2 January 2003 - Free CXC Past Paper with Answers

CSEC Physics Paper 2 January 2003 Questions

Every question from this paper as text. See the answers and worked solutions. Questions are the property of the Caribbean Examinations Council; Caribbean AI is not affiliated with CXC.

Question 1 (30 marks)

A bicycle pump is modified by replacing the handle with a flat plate onto which masses can be placed. The plate carries a attached pointer that is next to a vertical scale as shown in Figure 1. The bottom of the pump is sealed so that a fixed mass of gas is trapped inside. Initially masses, M, are added to the flat plate until the pointer reaches the 5 cm mark. The masses are then removed in steps, the trapped gas expands and drives up the piston, increasing the upward displacement L. Corresponding values of L and M are recorded in the table below.

(Assume the temperature of the gas is kept constant throughout the experiment.)

TABLE 1

Mass M(kg)	118	48.0	25.0	13.0	6.00	2.00
Displacement L(cm)	5.00	10.0	15.0	20.0	25.0	30.0
$\frac{1}{L}$ (cm $^{-1}$ )

[30 marks]

(a)

Calculate corresponding values of $\frac{1}{L}$ and complete Table 1.

[4 marks]

(b)

Plot M vs $\frac{1}{L}$ on the graph paper on the opposite page.

[9 marks]

(c)

Determine the slope, S, of the graph and give its unit.

[4 marks]

(d)

What is the value of L when M = 0?

[2 marks]

(e)

The results of this experiment can be used to verify Boyle's Law. State Boyle's Law as clearly and as completely as you can.

[3 marks]

(f)

State TWO precautions that Boyle's Law suggests for this experiment?

[2 marks]

(g)

The piston has a radius of 2.5 cm. Calculate its area in m $^2$ .

[3 marks]

(h)

Calculate the pressure applied to the trapped mass of gas when a mass of 100 kg rests on the flat plate.

[3 marks]

Question 2 (15 marks)

(a)

Explain what is meant by the term 'electric current' and give the SI unit for an electric current.

[3 marks]

(b)

Figure 2 shows the internal layout of a torchlight (flashlight) and its electrical circuit.

(b)(i)

In the space below draw the circuit symbol used to represent one of these cells.

[1 mark]

(b)(ii)

State the type of energy conversion which takes place in these cells.

[1 mark]

(b)(iii)

The component labelled Q is used to connect the copper strips thereby complet-ing a closed circuit. Name this component.

[1 mark]

(c)

The voltage of each cell is 1.5 V and the bulb has a resistance of 6 $\Omega$ .

(c)(i)

Calculate the current flowing in the circuit.

[3 marks]

Question 3 (13 marks)

(a)

Describe the nature and origin of the following particles:

(a)(i)

$\alpha$ – particle:

[3 marks]

(a)(ii)

$\beta$ – particle:

[3 marks]

(b)

$\beta$ – particles move at much greater speeds than $\alpha$ – particles but cause much less ionization when passing through air. Give TWO reasons why this is so.

Question 4 (14 marks)

(a)(i)

State what is meant by the term 'change of phase.'

[1 mark]

(a)(ii)

List TWO features that are characteristic of a phase change.

[2 marks]

(a)(iii)

Ice initially at $-5^\circ C$ is heated until steam is formed. Sketch a graph showing how the temperature of the ice would vary with time.

[4 marks]

(b)

Specific Heat Capacity of Ice = 2100 J kg K $^{-1}$

Question 5 (16 marks)

Figure 3.

[16 marks]

(a)

Figure 3 shows two household appliances connected in parallel to the electricity supply.

(a)(i)

Give TWO advantages of connecting electrical appliances in parallel.

[2 marks]

(a)(ii)

Explain the purpose of the fuses.

[2 marks]

(a)(iii)

In connecting the stove, an earth wire is also used. State its function.

[1 mark]

(b)

Suppose the supply voltage were 220 V d.c. and the electric stove and light bulb are rated at 1500 W and 150 W respectively.

(b)(i)

Select ONE fuse of correct rating for the electric stove from the list below and explain your choice.

1.0 A, 2A, 10 A, 15 A

[5 marks]

(b)(ii)

Calculate the TOTAL current drawn from the supply if BOTH appliances are being operated.

[4 marks]

(b)(iii)