CSEC Physics Paper 2 May/June 2006 - Free CXC Past Paper with Answers

Explain what is meant by 'electrical resistance'.

The circuit shown in Figure 1 shows the interconnection between electrical devices, B and C, and voltage source A.

Figure 1

Identify the type of connection employed in this circuit.

Give the meaning of the circuit symbols labelled: B C

Name the type of voltage produced at A.

A fluorescent lamp is rated at 15W, 120V. Calculate the current which the lamp draws from the main supply.

Calculate the resistance of this lamp while it is lit.

When the lamp is lit, 4 W of the energy supplied is lost as heat. Calculate the efficiency of the lamp.

Figure 2 shows successive stages in the generation of a transverse wave on a stretched slinky spring.

Figure 2

Indicate on Figure 2F by appropriately labelling a) the position of a crest b) the position of a trough.

Draw labelled arrows on Figure 2E to show a) the direction of the wave b) the direction of hand movement needed to produce this wave.

Indicate on Figure 2A the direction of hand movement needed to produce a longitudinal wave.

In a classroom demonstration a student uses a slinky spring to generate waves of frequency 5 Hz with 0.65 metres separation between successive crests. Determine the speed of these waves.

(i) Deduce whether the velocity of a sound wave will increase, decrease or remain constant when the wave travels from a denser to a less dense medium, given that the frequency remains constant and the wavelength decreases.

Compare the waves produced on the slinky spring in part (b) with a typical sound wave in terms of the motion of the particles. Transverse wave on slinky spring Sound wave

In Figure 3 below, a ship sends out pulses of high-frequency sound (ultrasound) which are reflected from the sea bed and received at the ship every $1.2 \times 10^{-2}$ seconds.

Figure 3

Calculate the depth of the sea bed below the transmitter.

(Speed of sound in sea water = $1\,500 \text{ m s}^{-1}$)

Define 'the moment of a force'.

State the principle of moments.

A cyclist hangs his bicycle with the rear wheel in contact with the ground and the handle attached to a light string as shown in Figure 4. The entire assembly is in equilibrium.

Indicate by drawing arrows on Figure 4 the forces acting on the bicycle.

Write TWO equations relating these forces.

The bicycle has a mass of $20 \text{ kg}$. Use the result you obtained in Part (c) (ii) to determine the tension in the string.

[Acceleration due to gravity, $g = 10 \text{ m s}^{-2}$]

Complete Table 2 below showing the International Insulation Colour Code.

Table 2

Fuses are sometimes used to protect electrical equipment from excess current. Explain how a fuse works.

A household has the following appliances

• Heating iron rated at $1200 \text{ W}$, $110 \text{ V}$
• Television set rated at $70 \text{ W}$, $110 \text{ V}$
• Electrical fan $52 \text{ W}$, $110 \text{ V}$

Calculate the total power consumed by these devices.

These devices are in use for 4 hours per day. Calculate the energy consumed in kilowatt-hours in a 30-day month.

Calculate the bill for the month if each unit of electricity costs $40\text{c}$.

Assuming that these devices are connected in parallel across the mains supply, and are switched ON, calculate the TOTAL current drawn from the mains.

Fuses are available with the following current ratings: $5\text{A}$, $10\text{A}$, $15\text{A}$, $25\text{A}$. Select a suitable fuse for protecting these devices.