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0580 PHYSICS 2

CAMEROON GENERAL CERTIFICATE OF EDUCATION BOARD

General Certificate of Education Examination

JUNE 2018 ORDINARY LEVELS

Subject title PHYSICS

Paper No. 2
Subject Code No. 0580

Two and a half hours

Answer ALL FIVE questions.

Section 1 is designed to be answered in1 hour and Section 2 in 11/2 hours

You are advised to divide your time accordingly

In Section II answer EITHER the a, b, and c OR the d, e, and f of each question

For your guidance the approximate mark for each part of the question is indicated in brackets

You are reminded of the necessity for good English and orderly presentation in your answers.

In calculations you are advised to show all the steps in your working, giving your answer at each stage.

Where necessary, assume: the acceleration of free fall, g = 10 m s-2

Calculator are allowed

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SECTION I
Answer all questions in one hour.
1. (a) State
(i) Faraday's law of electromagnetism. (1 mark)
(ii) Lenz's law of electromagnetism. (1 mark)
(b) A transformer in a radio set delivers 5 A at a voltage of 6 V from a socket connected to a 240 V line.
(i) State whether this transformer is a step up or a step down transformer. (1 mark)
(ii) Assuming the transformer is 100% efficient, calculate the amount of current that enters the socket.
(2 marks)

2. (a) State the law of conservation of linear momentum. (2 marks)

(b) A car of mass 1000 kg is travelling at 60 ms-1 (2 marks)

(i) Calculate the momentum. (2 marks)
(ii) If It crashes into a wall and is brought to rest in 0.5 s, calculate the force it exerts on the wall.
(2 marks)

3. (a) (i) State Two physical properties of a conductor which affect its resistance. (2 marks)
(ii) Calculate the total resistance in the circuit in figure 1. (2 marks)
(iii) Calculate the current flowing through the 5 Ω resistor. (2 marks)

4. (a) (i) State the S.I unit of temperature and its lowest value. (2 marks)
(ii) What is the thermometric property of a liquid-in-glass thermometer? (1 mark)

(b) (i) State one use of a mercury in glass thermometer. (1 mark)

(ii) A liquid-in-glass thermometer has a fine (narrow) bore, a thin walled bulb, and a blackened bulb.
Explain the significance of the underlined words to the effective functioning of the thermometer.
(3 marks)

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5. (a) Figure 2.0 show a parachutist falling freely from a great height until he attains a constant velocity.

(i) What name is given to that constant velocity? (1 mark)

(ii) Copy figure 2.0 and indicate all the forces acting on it . (3 marks)
(iii) Which of these forces increases with speed? (1 mark)
(iv) What is the net force on the body when the velocity in (i) is attained? (1 mark)
(v) Explain what will happen to the time to attain constant velocity if a larger parachute was used.
(2 marks)

6. (a) (i) State the difference between distance and displacement. (2 marks)
(ii) Define velocity and state its unit of measurement. (2 marks)

(b) Figure 3.0 shows a velocity-time graph for a cyclist in a race.

(i) Describe the motion of the cyclist in section AB and BC. (2 marks)
(ii) State the significance of the gradient of the section AB. (1 mark)
(iii) Over which section of the graph does the cyclist attain maximum velocity? (1 mark)

SECTION II
Answer all questions choosing, EITHER the a, b and c OR the d, e, and f of each question

Answer EITHER 7 a, b and c

7. (a) (i) Define the principal focus of a converging lens. A ray diagram may be used in your definition.
(2 marks)
(ii) Name one optical instrument that uses a convex lens to produce a magnified image. (1 mark)
(iv) Draw a ray diagram to show how the image in (ii) above is formed. (4 marks)
(v) State two other properties of the image formed. (2 marks)

(b) Describe an experiment to determine the refractive index of a glass block. Include in your description:
- a list of apparatus needed
- a diagram of the set-up
- the procedure you will use
- the precautions to be taken (6 marks)

(c) A converging lens has a focal length of 50 cm. An object is placed 80 cm from the lens and an image is
produced on a wall 240 cm from the lens.
(i) Calculate the magnification of this image. (2 marks)
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(ii) State the nature and orientation of this image. (2 marks)
(iii) What property of light is responsible for the formation of this image by the lens? (2 marks)

OR 7 d, e and f

(d) (i) Define the specific latent heat of a substance. State its unit. (2 marks)
(ii) Name a substance with a high specific latent heat. State one use of this substance which is due to its
high specific latent heat. (2 marks)
(iii) Explain why a burn from steam at 100 0C is more severe than one from boiling water at the same
temperature. (2 marks)

(e) (i) Describe an experiment to show that different materials (solids) conduct heat at different rates
- A list of apparatus needed.
- A diagram of the set-up
- The procedure you will use
- The precautions to be taken (5 marks)

(ii) Name three situations in which these differences in conductivity between different materials are put
to use. (3 marks)

(f) A student noticed that when fire is burning in a firewood kitchen, cold air flows into the kitchen through the
door while the smoke moves out through a hole high up in the wall.
(i) Name the phenomenon that causes this observation. (1 mark)
(ii) Briefly explain how this observation occurs. (3 marks)
(iii) Name one daily occurrence due to this phenomenon. (1 mark)

Answer EITHER 8 a, b and c OR 8 d, e and f

Answer EITHER 8 a, b and c

8. (a) (i) What is an elastic material? (1 mark)
(ii) State Hooke's law. (2 marks)

(b) A copper wire is suspended vertically from the ceiling. Its lower end is being loaded. The length of the spring L (cm)
as the load F(N) is being varied from the ceiling. Its lower end is being loaded. the length of the spring 1(cm) as
the load F(N) is varied are shown in the table below:
F/N 0.0 2.0 4.0 8.0 10.0 14.0 16.0
l/cm 15.00 15.15 15.30 15.60 15.75 17.60 18.2
E/cm 0.00

Complete the table by calculating the extension for each force. (the first one has been done for you).

(2 marks)
(i) Draw a graph of F(N) on Y-axis versus e(cm) on X-axis. (5 marks)
(ii) Determine the slope of your graph. (2 marks)
(iii) Determine from your graph what load will stretch the wire to a length of 15.7 cm. (2 marks)
(iv) Name the type of energy stored in the stretched wire. (1 mark)
(v) State with a reason whether this wire obeys Hooke's law. (2 marks)

(c) State the energy changes that occur from the moment a stone is released at a height to the moment it comes to
rest on the ground. (3 marks)

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OR 8 d, e and f
222
(d) 86𝑅𝑎 is one of the isotopes of random with a half – life of 3.8 days. It undergoes radioactivity by alpha particles
emission resulting in a transmutation process.
Define each of the underlined terms or expressions. (3 marks)

(e) Alpha particles tracks in a cloud chamber are thick, straight and short, while beta-particles tracks are thin, wavy
and long. State the reason for each of the characteristics underlined above (6 marks)

(f) In the absence of a known radioactive source, a rate-meter indicated an average reading of 25 counts/min. The
table shows how the reading of the rate meter varies with time in the presence of a known radioactive substance.

Time (min) 0.0 2.0 4.2 8.6 12.0 18.4 22.0

Readings 985 725 475 225 145 65 45
(count/Min)
Corrected count 960
rate (counts/min)

(i) What name is given to the count rate of 25 counts/min? (1 mark)

(ii) Complete the table by calculating the corrected count rates. One example has been done for you.
(6 marks)
(iii) Draw a graph of the corrected count rate on the Y-axis versus time on the X axis. (6 marks)
(iv) Use the graph to determine the half-life of the radioactive source. (3 marks)

Answer EITHER 9 a, b and c OR 9 d, e and f

Answer EITHER 9 a, b and c

9. (a) Figure 4.0 shows a negatively charged polythene rod brought close to an uncharged suspended metal coated ball
It is observed that the ball moves.

(i) In which direction does the ball move? (1 mark)

(ii) What type of force exist between them? (1 mark)
(iii) Name two factors that affect the magnitude of this force. (2 marks)
(iv) Explain how the movement in (i) comes about. (2 marks)
(v) Why is it easier to charge a polythene rod than to charge a copper rod? (2 marks)

(b) Figure 5 shows two conductors A and B.

A B

-6000V +4000V

Figure 5

(i) What is the potential difference (p.d) between the two conductors? (2 marks)
(ii) If A and B are linked by a conducting wire, in which direction will the electron flow? Explain
(2 marks)
(iii) When do the electrons stop flowing? (1 mark)

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(iv) How much work must be done to bring a charge of 10 -5 C from earth to the 4000V conductor?
(2 marks)

(c) A current of 10 A flows in a conductor for 8s

(i) What do you understand by the current of 10 A? (2 marks)
(ii) Calculate the number of electrons that flow in the conductor, given that the charge of an electron is
1.6 x 10-19 C

OR 9 d, e and f

(d) List two ways by which electrical energy could be lost in a transformer and in each case explain how this loss
could be minimised. (2 marks)

(e) Figure 6.0 shows a conductor AB placed in the magnetic field, N – S of two magnets and connected to centre-zero
galvanometer.

If the conductor AB is moved vertically up, it is observed that the galvanometer deflects.

(i) Explain why the galvanometer deflects? (3 marks)

(ii) If the direction of movement of the conductor is reversed, state and explain what is observed on the
galvanometer. (2 marks)
(iii) State two factors that determine the magnitude of deflection. (2 marks)
(iv) Name any rule that could be used to determine the direction of the magnetic field lines about the straight
current A carrying conductor (1 mark)

(f) Distinguish between a hard magnetic material and a soft magnetic material giving an example of each
(4 marks)
Figure 7.0 shows three rectangular metal blocks A, B, and C. Blocks A is a permanent magnet of known
polarity, B is a magnetic material and C another permanent magnet

Explain how you would use block A to show a group of Form 5 students that B is a Magnetic material and
C is a permanent magnet (3 marks)

3-/0580/2/B/Q

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Lecture notes, more papers and a lot more for all levels are at www.alstug.com

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