SECTION 1 (65 MARKS)
Answer all the questions in this section in the spaces provided
- The data in the table below represents the motion of a vehicle over a period of 7 seconds.
| Time (sec) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|
| Displacement (m) | 0 | 20 | 40 | 60 | 80 | 95 | 105 | 110 |
(a) Plot on the grid provided a graph of displacement (y-axis) against time. (5 marks)
(b) Describe the motion of the vehicle for the first 4 seconds. (1 mark)
(c) Determine the velocities at 4.5 s and 6.5 s. Hence or otherwise determine the average acceleration of the vehicle over this time interval.
- Study the circuit diagram in figure 1 and answer the following questions.
- Calculate the effective resistance between Y and Z. (3 marks)
- Determine the current through the 3 Ω resistors. (6 marks)
- One of the 6 Ω resistors has a length of 1.0 m and cross-sectional area of 5.0 x 10-6 m2. Calculate the resistivity of the material. (3 marks)
(a) An object O is placed in front of a convex mirror as shown in figure 2.
(i) Draw to scale a ray diagram to show the position of the image. (5 marks)
(ii) Determine the magnification. (3 marks)
(b) An object placed in front of a convex lens of focal length 10 cm produces an image at a distance of 15 cm from the lens and on the same side as the object.
Determine the position of the object. (4 marks)
(a) Draw a ray diagram to show how a convex lens works as a magnifying glass. (5 marks)
(b) The diagram in figure 3 shows a certain eye defect.
- Name the defect.
- Draw on the same diagram an arrangement to correct the defect. (1 mark)
(c) (i) Explain why a pail of water can be swung in a vertical circle without the water pouring out. (3 marks)
(ii) A car of mass 1200 kg is moving with a velocity of 25 m/s around a flat bend of radius 150 m. Determine the minimum frictional force between the tyres and the road that will prevent the car from sliding off. (4 marks)
(a) (i) State the law of electromagnetic induction. (2 marks)
(ii) Describe an experiment to demonstrate Faraday’s law. (4 marks)
(b) (i) A researcher studying the behaviour of a step-up transformer made the following observations:
“More joules per coulomb and fewer coulombs per second at the output than at the input terminals.”
Explain why the observation does not imply a violation of the principle of conservation of energy. (4 marks)
(ii) A transformer of 480 turns in the primary coil is used to connect a 9-volt AC electric device to a 240 V AC mains power supply. Calculate the number of turns in the secondary coil. (3 marks)
SECTION II (15 MARKS)
Answer one question from this section
(a) Distinguish between stationary and progressive waves. (1 mark)
(b) (i) Describe how a Young’s double slit may be made in a laboratory. (2 marks)
(ii) State the condition for a minimum to occur in an interference pattern. (1 mark)
(c) The sketch graph in figure 4 shows the results of an experiment to study diffraction patterns using a double slit.- Sketch an experimental setup that can be used to obtain such a pattern. (4 marks)
(ii) Name an instrument for measuring the intensity. (1 mark)
(iii) Explain how the peaks labeled A and B, and troughs labeled C are formed. (6 marks)
(a) Describe how a p-type semiconductor is formed. (3 marks)
(b) Distinguish between p-n-p and n-p-n transistors. (1 mark)
(c) The sketch in figure 5 shows the results of an experiment where a transistor was used as a voltage amplifier.
Explain how the voltage amplification factor, β, may be obtained from the sketch graph. (4 marks)
(d) (i) Draw a circuit diagram of a p-n-p transistor operating in the common emitter (C-E) mode. Indicate on the diagram the directions of the collector current IC, the base current IB, and the emitter current IE. (4 marks)
(ii) Write the equation relating IC, IB, and IE. (1 mark)
Identify the type of biasing in each of the junctions of a transistor in operation. (2 marks)
(c) The sketch graph in figure 4 shows the results of an experiment to study diffraction patterns using a double slit.
