Changkat Changi Secondary School

Candidate Name /

Class

/ Register Number
/

CHANGKAT CHANGI SECONDARY SCHOOL

MOCK ‘O’ Level Examination 2011

Subject : Science (Physics)

Paper No : 5116/02 / 5117/02

Level : Secondary 4 Express /

Secondary 5 Normal Academic

Date :

Duration : 1 hour 15 minutes

Setter : Mr Melvin Ng

______

INSTRUCTIONS TO CANDIDATES

Do not open this booklet until you are told to do so.

Write your name, class and register number in the spaces at the top of this page.
Answer all questions in Section A and any two questions in Section B.
In calculations, you should show all the steps in your working, giving your answer at each stage.
Enter the numbers of the Section B questions you have answered in the grid below.
The number of marks is given in brackets [ ] at the end of each question or part question.
For Examiners’ Use / Marks
Section A / / 45
Section B
/ 10
/ 10
Total / / 65
Expected Grade / Actual Grade
Parent’s / Guardian’s
signature

This Question Paper consists of 19 printed pages.

Section A [45 Marks]

Answer all the questions in the space provided.

1 / A beaker can hold 250 cm3 of liquid. When it is filled with paraffin (density 0.80 g/cm3 ), the total weight is 2.6 N. Assume g = 10N/kg.
(a) Calculate the mass of the filled beaker [2]
(i) in kg, ………………………………………………………………………………………
(ii) in g, ………………………………………………………………………………………
(b) Calculate the mass of paraffin in the beaker. [2]
(c) Calculate the mass of the beaker. [1]
2 / State which component of the electromagnetic spectrum is used in each of the following.
(a) / Television remote controllers ………………………………………………… / [1]
(b) / Satellite television ………………………………………………… / [1]
(c) / Treating cancer ………………………………………………… / [1]

3 When steam condenses to form water at room temperature, state what happens to the molecules during the condensation process in terms of:

(a) molecular speed

………………………………………………………………………………………….. [1]

(b) Intermolecular distance

………………………………………………………………………………………….. [1]

4 / Fig. 4.1 shows a lantern that is held up by two wires. The tension in each wire is 16 N and the angle between the wires is 120o

On Fig. 4.1, draw a vector diagram to scale in order to determine the weight of the lantern.

State the scale used.

scale: 1 cm represents ……….

weight = …………………..N [4]

5 / Fig. 5.1 below shows a ray of light being refracted at a glass surface. Fig. 5.2 shows the incident ray at a different angle.

(a) / Calculate the angle that the refracted ray makes with the normal in Fig. 5.2. / [2]
(b) / Determine the critical angle for glass. / [2]
(c) / If the angle of incidence is increased to 60º as shown in Fig. 5.3, is it possible for total internal reflection to occur? Explain your answer.
……………………………………………………………………………………………..
………………………………………………………………………………………………
………………………………………………………………………………………………
……………………………………………………………………………………………… / [1]
6 / A motorcycle and a rider have a combined mass of 300 kg. During a trial run on a racetrack, the motorcycle accelerates uniformly from rest at a constant rate of 8.0m/s2 until the speed is 40 m/s. The motorcycle then travels at a constant speed until it has gone a further 600m. It then comes to rest with a constant deceleration in a further 8.0 s.
(a) / On the grid of Fig. 6.1, plot a speed-time graph to show the motion of the motorcycle. [3]

(a) / Calculate the kinetic energy of the motorcycle and the rider when they are travelling at a constant speed.
kinetic energy = …………………….. J [2]
(b) / Calculate the braking force on the motorcycle on the final 8.0s of the journey.
braking force = …………………….. J [3]

7 Below shows a system designed to control the pressure of the engine steam. The valve opens when there is excess steam pressure from the engine.

(a) Using the principle of moment, calculate the minimum upward force, F, on the valve just before lifting it up.

Force, F = ………………[3]

(b) State one modification to the design of the system in order to open the valve at a higher steam pressure.

.....………………………………………………………………………………..…[1]

8 A sound wave has a frequency of 400 Hz. The speed of sound in air is 320 m/s.

(a) Calculate the wavelength of the sound wave in air.

Wavelength = ...... [2]

(b) A sound wave of the same frequency is produced in water. Describe and explain how the wavelength of the wave will be different from that in part (a).

………………………………………………………………………………….

………………………………………………………………………………[2]

9 One method of painting a metal panel uses electrostatic charges. A paint spray produces paint droplets, all of which are given a positive charge. The metal panel is given a negative charge, as shown in the diagram below.

(a) Explain why the droplets spread out as they leave the nozzle.

………………………………………………………………………………….

……………………………………………………………………………….[1]

(b) Besides helping the paint droplets to spread out, state one other advantage of using electrostatics in this way to paint the metal panel.

………………………………………………………………………………….

……………………………………………………………………………….[1]

10 The figure below shows three resistors connected to a battery.

A current of 3 A flows through the resistor X.

(a) Calculate the charge flowing through resistor X in one second. [2]

(b) Calculate the combined resistance of the circuit. [2]

11 Figure 11.1 below shows the circuit used to investigate the force on a wire carrying a current in a magnetic field.

(a) What is the direction of the force on the section AB of the wire? [1]

……………………………………………………………………………………

(b) Changes were made to the circuit as stated above. For each of the changes, state what happens to the force on the wire AB.

(i) The number of cells in the battery is reduced. [1]

……………………………………………………………………………

(ii) The terminals of the battery are reversed. [1]

……………………………………………………………………………

SECTION B (20 marks)

Answer any TWO questions

Write your answers on the lined paper provided and, if necessary, continue on separate answer paper.

10. / A simple tower crane consists of an arm pivoted within the tower. When nothing is hung from the crane arm, it is balanced about the pivot, P as shown in Fig (i).

Fig (i)
The crane is used to lift a 50 kN load that is suspended 15 m from pivot P, through a vertical distance of 12 m. In order to balance the load, a counterweight C is located 10 m from the pivot, P. Fig (ii) and Fig (iii) shows the initial and final positions of the load respectively.

Fig (ii) Fig (iii)
(a) / Calculate the work done against gravity to lift the load / [2]
(b) / Calculate the mass of C. / [2]
(c) / Explain why the weight of the crane arm is not required in the calculation in part (b). / [1]
(d) / If the same load is to be moved 6 m towards pivot P, how much towards or away from the pivot P should the same counterweight move? / [2]
(e) / State whether the crane is more stable in Fig (ii) or Fig (iii). Explain your answer. / [2]
(f) / Suggest a way to redesign the tower crane to make it more stable. / [1]
11 / (a) / Two insulated wires A and B are of the same material and length, but with different thickness, were connected into a circuit. Readings of the current and the potential difference were taken for each of the wire. The graphs below represent the results of the experiment.

(i) / From the graph, calculate the resistance of wire A. Show all working clearly. / [2]
(ii) / Which wire has a smaller cross sectional area? Explain how you arrived at your answer. / [3]
(b) / A circuit is set up as shown below.

(i) / What is the potential difference across AB? / [2]
(ii) / Using the answer in (bi) or otherwise, calculate the resistance of R3. / [3]
12 / (a) / The figure below shows a coil of wire wound around a rectangular tube.

(i) / Mark arrows in compasses A, B and C in the above diagram to show the direction of the magnetic field at each position after the switch has been closed. / [1]
(ii) / Two iron rods are placed next to each other at the bottom of the tube. When the current is switched on, describe and explain what happens to the iron rods. / [2]
(iii) / With the aid of a labelled diagram, explain how an electric current can be used to demagnetise a magnet. / [3]
(b) / Describe how the circuit breaker shown below operates.
/ [4]

END OF PAPER

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