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G.C.E. O/L 2016 - New Syllabus Revision Excersises - Science ( No. 06) Science 1 – Duration 1 Hour.

01. What is the most abundant element present in living matter?

1. Carbon, Hydrogen, Oxygen, Nitrogen 2. Carbon, Hydrogen, Oxygen, Sulphur

3. Carbon, Hydrogen, Oxygen, Phosphorus 3. Carbon, Hydrogen, Nitrogen, Phosphorus

2. A nonflowering plant which contain seeds is

(1) paddy plant. (2) Cycas plant (3) Poganatum plant. (4) Salveenia plant.

3. What is the acceleration created by a force of 16 N which acts on an object of 2 kg mass?

(1) 2 m s-2 (2) 4 m s-2 (3) 8 m s-2 (4) 12 m s-2

4. Which of the following reaction is relatively of low speed?

(1) Burning of a match stick (2) Reaction between Mg and HCl

(3) Corrosion of iron. (4) Reaction between NaOH and Al

5. What is the resultant force of the following system of force?

(1) 8 N to the right (2) 12 N to the left (3) 32 N to the left (4) 32 N to the right

6. Which of the following is a supporter of combussion ?

1.Hydrogen 2.Nitrogen 3. Carbon dioxide 4.Oxygen

7. Which of the following is a solid-solid homogenious mixture?

1. Salt solution. 2. Mixture of stone, sand and cement.

3. Stainless steel 4. Alcohol solution.

8. A complex permant tissue is

1. parenchima tissue. 2. colenchima tissue.

3. phloem tissue. 4. scherenchyma tissue.

9. Following diagram shows a light ray entering the glass-air interface through a glass media. Which of the

following diagram shows the correct path of it in air.

A B C

1. Only A 2. Only C 3. Only A and C . 4. All A, B and C.

5 N

7 N

20 N

Air

Aවාතය

Glass

Glass

Air

Glass

Air

Note ( ^i& Answer all the questions. ^ii& Select the most suitable answer out of 1 to 4 for the questions given.

^iii& Put (x) in the correct space. ^ iv& Follow the other instructions given in the paper.

2

10. Which of the following statement is correct regarding musical instruments?

1. Violin, guitar and flute are instruments with vibrating strings.

2. Flute, thubla and combuwa are instruments with vibrating air columns.

3. Drums thublawa and udekkiya are instruments with vibrating membranes.

4. Violin, guitar and thubla are instruments with vibrating strings.

11. Which of the following is not a characteristic of sexual reproduction?

1. Produce gametes. 2. Having two maternal and paternal being.

3. Meiosis take place. 4. Produce identical offsprings.

12. Due to the formation of chemical bonds,

1. the outermost energy level of the element becomes unstable.

2. element become stable

3. number of energy levels in elements get increase

4. non of the above occurs.

13. B

The correct statement regarding liquids present in A and B vessels is,

1. A & B both contain strong bases.

2. A & B both contain weak bases.

3. A contains a strong base while B contains a weak base.

4. A contains a weak base while B contains a strong base.

14. Following a,b, and c figues shows three types of tissues present in human body. The locations of these

tissues respectively is,

1. heart,stomach,tongue 2. heart, liver, tongue

3. stomatch, skin, heart 4. skin, tongue, heart

15. An automobile travels 800m in 1st second and 1000 m in 2nd second. What is the average speed of it?

1 10 m s-1 2. 15 m s-1 3. 600 m s-1 4. 900 m s-1

16. ‘AX’ of the following diagram shows a light ray falling on the point X of a convex mirror. ‘F’ is the focus

of the mirror. The correct direction of the reflected ray is,

1. XB 2. XC

3. XD 4. XF

A

NaOH NH4OH

F

X

A

B

C

E

D

3

17. Which of the following is an incorrect statement regarding reflex arc?

1. Reflex arc is an immediate automatic response

2. Reflex arc is the functional unit of the nervous system

3. Two neurons are adequate to function of a reflex arc.

4. Reflex arc always connected with the central nervous system.

18. The correct structural formula of chloroethene is,

19 Following figure shows a sketch diagram of a

reflex arc. Receptor and the effector of it is,

1. skin and muscles of the hand

2. skin and smooth muscles

3. skin and central nervous system

4. skin and neuron

20. Consider the following statements regarding sound waves.

A – sound waves are longitudinal waves.

B – A medium is necessary for the transmission of sound waves.

C – Sound waves are not travelled through liquids.

correct statement/s of the abobve is/are,

1. Only A. 2. Only B. 3. Only A and B 4. only A and C

21. Specific heat capacity of water is 4200 J kg-1 0C-1 . What is the amount of heat required to increase the

temperature from 20 0C to 100 0C of a 300g of water?

1. 1008 J 2. 332 J

3. 100.8 kJ 4. 332 kJ

22. Which of the following statement is correct regarding airobic and anorobic respiration?

1. All living beings are respiring aerobically.

2. All living beings are respiring aerobically as well as anorobically.

3. Oxygen is necessory for the aerobic respiresion while oxygen is not necessory for the

anorobic respiration.

4. The amount of energy generated by the aerobic respiration is less while amount of

energy generated by the anorobic respiration is high.

23. Which of the following is a polymer with side chains?

1. Starch. 2. Glucose.

3. Celliulose. 4. DNA .

24. Which of the following is an example for an instance that cathodic protection is used to protect an iron plate

from corrosion.

1. A galvanized bucket. 2. Samon tin.

3. Painted gate. 4. Grees plated iron equipment.

brown green orange

e

silve

r

CH

H Cl

CH

H Cl

CH

H F

CH

H H

CH

H Cl

CH

H H

CH

H F

CH

H Cl

1. 2. 3. 4.

4

25. Colour bands of a resistor is green,brown and

orange respectively. (green =5, brown=1 and

orange=3)

1) 15 Ω 2) 51 Ω 3) 15 kΩ 4)100 kΩ

26. Which of the following is an acid base nutralizing reaction?

1. 2 HCl + 2 Mg MgCl2 + H2

2. CaCO3 CaO +CO2

3. HCl + NaOH NaCl + H2O

4. BaCl2 + Na2 SO4 Ba SO4 + 2NaCl

27. Figure shows an object (OA) placed infront of a

convex lence. Focus of the lence is denoted by F.

Following are some statements regarding the

image formed by it.

P – smaller than the object.

Q – Image is up right

R – Image is vertual

Correct statement/s from the above is/are,

1. Only P 2. Only Q 3. Only P and Q 4. Only Q and R

28. Followings are tree polimers which have different structures.

A B C

From the above, less density polethene and Bakelight is shown respectively by,

1. A and B . 2. B and C .

3. A and C. 4. only C

29. Following figure shows the location of particles of a string at a certain instance which vibrated transversly.

Which of the following is incorrect regarding this diagram?

1. A and C are crests. 2. OX length is termed as displacement.

3. A C is wave length. 4. A and B are crests.

30. Following figure shows how a force ( P ) acts on an object (A ) placed on a rough horizontal serface. Force

P is gradually increased. P = 40 N it comes to the limiting state. Which of the following statement is

incorrect regarding F friction force acts on A?

1) When P is increased F also gradually increased

2) The maximum value of P is 40 N.

3) When A is moved F decreased up to 40 N.

F

A

O

F

A

P

B

Displacement

0

X A C

D

පහටම

5

4) When A is stable, what ever happens to value of P, F=40 N.

31. Select the correct statement from the followings.

1) Bases are release H+ ions when it is in an aqueous solution

2) Acids are release OH- ions when it is in an aqueous solution

3) Acids are release H+ ions when it is in an aqueous solution

4) Bases are release H+ ions and OH- ions when it is in an aqueous solution

32. Which of the following statement is correct regarding relative atomic mass of a element?

1. 2.

3. 4.

33 Following is how the characteristics are inherited

in monohybrid breeding between tall and dwalf

garden pea plant

Heterozygous tall plants in F2 generation

can be seen in,

1 A and B . 2 B and C .

3 C and D . 4 in all.

34. Which of the following statement is incorrect regarding heat capacity of an object.

1. Heat capacity is changed according to the mass.

2. Units of the heat capacity is J kg-1 0C-1.

3. Heat capacity of an object of 1 kg is equal to the specific heat capacity of that.

4. Heat capacity is, the amount of heat needed to increas the temperature of an object 10C .

35. Following are some classification patterns of living beings.

A- animals with wings, animals without wings

B- plants,bushes,trees

C- prokaryotic , eukaryotic

D- animals who can swim, animals who can fly

Which of the above belongs to natural classification?

1. only A 2. Only B and D 3. Only C 4. Only A, B and D

36. Which of the following is not relater with the homeostasis of human nbody?

1. Body temperature. 2. Glucose concentration of blood.

3. Production of urea. 4. Concentration of water.

37. Select the correct statement about electrolysis.

1. Electrode which connected to the – terminal is cathode

2. Electrode which connected to the + terminal is cathode

3. The electrode at which oxidisation occurs is cathode

4. The electrode at which reduction occurs is anode

38 . It is noted as 240 V, 100 W in an electric equipment. What is the current flows through the equipment

when it is opperated under due voltage?

1) 5

12 𝐴 2)

12

5 𝐴 3) 5A 4) 12A

Weight of an atom of an

element 1

12 x 12

C 6 mass of an atom

mass of an atom of an element

1

12 x 12

C 6 mass of an atom

mass of an atom of an element

12 x 12 C 6 mass of an atom

mass of an atom of an element

1

16 x 12

C 6 mass of an atom

P T

t

T

t

gametes

eats

X

T t T t

A B C D F2 generation

6

39. Which of the following cauces an instant impact on the carbon cycle?

1 Increase the monsoon rain. 2 Burning of fossil fuals.

3 Ozone layer depleation. 4 Adding fertilizers to soil.

40 Sustainable development and eco management is,

1. Using environmental resources systematically, enabling the future generation to use.

2. Efficiently using Sri Lanken land area according to the population.

3. Developing the environment by protecting the environmental resources while

preventing the environmental polution.

4. Managing the environment to devide the resources to the ratio of population.

7

G.C.E. O/L Examination - New Syllabus Revision Excersises - Science ( No. 06)

Science II Duration 3 Hours Note

Write answers clearly.

Use the space provided to answer all questions in Part A.

Select any 3 questions from Part B and answer.

Attach A and B together and handover at the end.

Part A – Structured Essay

1) Given below is a picture of a rainforest.

A)

I. Put the organization levels of the biosphere that can be seen in this forest appropriately in the

blank squares given. (01 mark)

II. Write two things cycle in this environment.

1………………………….. 2 ……………………………………. (02 marks)

B) The picture shows the environmental pyramid drawn

using the food chain activating in the forest. P, Q, R, S

represents the tropic levels.

I. Which letter represents the first trophic level? …………………………………………

II. To which tropic levels man belong? …………………………………………

III. What is depicted through this pyramid? …………………………………………………………….

P

Q

R

S

X

X X

Population

8

IV. Which percentage of energy contains in the P, enter to Q? …………………………

…………………………………………………………………………………………………………………( 01x 4 marks).

C)

I. If 3000 kcal quantity of energy contains in P, which is the gross quantity of energy contained

in S? …………………………………………………………………………………..… (02 marks)

II. Why is tropic levels amount in food chain limited to a maximum amount of 4?

…………………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………( 01 mark)

D) One study group stated that a particular animal species in the forest decreases drastically.

Students who thought of examining this based on scientific process presented several

suggestions. Put √ for correct ideas and × for incorrect ideas.

I The above statements are presented based on observations.

II It is not essential to identify the problem to build up hypotheses.

III It is sufficient to examine one hypothesis.

IV It is essential to limit variables to come to correct conclusions.

(06 marks)

2) Life tissues are categorized into two as permanent tissues and merismatic tissues. These tissues are categorized further.

A). I. Why do xylem tissues and phloem tissues identify as complex permanent tissues?

................................................................................................................................................

............................................................................................................................( 01 mark) II. To study the permanent tissues, it is ready to observe a thin layer of onion through the

microscope. Write the steps of the preparation of onion layer in order.

…………………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………………………………

…………………………………………………………………………………………………………… (03 marks) III. Draw a labelled diagram of a tissue that can be seen, when observing the onion layer through

microscope. (01

mark)

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B) I. Cell division occurs when producing the pollen of a flower and the growth of the phloem

tissue. Write two main differences between these two instances.

a. ……………………………………………………………………………………………………………………………

b. ……………………………………………………………………………………………………………………………

(02 marks)

II. New plants produce through the seeds that come from the fertilization of flowers. In

addition to that new plant can be taken by planting a stem of a plant. Complete the

following table based on the characteristics of these two reproduction methods.

by planting a stem of a plant

by planting seeds

Reproduction method

Possibility/Impossibility of getting plants with more characteristics of mother plant

(04 marks)

III. White flowers and red flowers are borne in two varieties of the same plant. If the dominant

factor is bearing red flowers,

i. Write the geno type of red flowers. ………………………………………

(Use R to show red flowers)

ii.Write the geno type of white flowers. ………………………………………

(02 marks)

IV. If the plant that has dominant red flowers is heterozygous, the generation F1 which is created

by grafting two plants with red flowers and white flowers;

i. Write the genotype ………………………………………

ii. Write the penotype ……………………………………… (02 marks)

10

3 )

The above diagram shows a set up prepared by a student at home, for the extraction of

cinnamon oil. For the apparatus A, a “Pittu mould” is used. B is an alluminium antenna sent

through a PVC tube. Cinnamon leaves are used as the raw material.

A)

I. What are the laboratory apparatuses that can be instead of A and B?

a. A = ……………………………………………… b. B = ……………………………………………( 02 marks)

II. Why is the apparatus ‘B’ more efficient

………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………

III. Name another raw material that can be used instead of cinnamon leaves.

………………………………………………………………………………………………………………………………………

IV. What is the type of solution made with water and cinnamon oil?

……………………………………………….

(01x3 marks)

B)

I. 20 g of cinnamon oil was mixed in 100 g of water. Fill in the blanks to show the above as the

mass fraction.

(02 marks)

II. What is the type of bond found in a water?

Mass fraction of cinnamon oil =

A B

+

Water out

Water in

Oil

Cinnamon leaves

Heating

11

……………………………………………………………………………………………………………………………………….

(01 mark)

III. Draw the nature of the bond found in a water molecule, in the box given below.

+

(02 marks)

iv. How many water molecules are present in one mole of water? ……………………………………………

........ (01 mark)

C. i. The molecular mass of water is 18. What is the molar mass of water?

………………………………………..

ii. Calculate the amount of moles contained in 36 g of water.

……………………………………………………………………………………………………………………………………..

……………………………………………………………………………………………………………… (02 x2 marks)

04).

A. The figure shows a car parked on a horizontal road.

i) State the reason for motionless status of the car based on Newton’s laws.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (01 mark)

ii) The figure given below shows a tyre in contact with the ground. Name the two forces

labelled as ‘X’ and ‘Y’ in the diagram.

X . . . . . . . . . . . . . . . . . . . .

Y . . . . . . . . . . . . . . . . . . . .

Y

X

12

(02 marks)

iii) What is the relationship between X and Y?

. . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . (01 mark)

iv) Minimum force needed to push the car forward is 600 N. One person horizontally applies a

forward force of 300 N. Find the magnitude and the direction of the extra force needed to push the car. Magnitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direction . . . . . . . . . . . (02 marks)

B. The side view of a front door of a care is shown in the picture.

The driver exerts a perpendicular force of 20 N at ‘P’ to open the door.

The distance from the axis of rotation of the door with hinges to the

point ‘p’ is 80 cm.

i) Calculate the moment of force created by the force of 20 N.

. . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .

(01 mark)

ii) Find the minimum force that should be applied to shut the door at ‘Q’ instead of ‘P’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (01 mark) .

C. The vehicle starts to move from a static position and moves in constant acceleration for two

minutes and obtains a velocity of 30 ms -1. It moves for another two minutes contantly

maintaining the velocity.

i) Find the accelaration of the vehicle.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (01 mark)

ii) Draw the Velocity – Time graph of the vehicle in the coordinate plane given below.

80cm

P Q 40cm

80cm

axis of

rotation of

the door

V (ms -1)

t (s )

10

30

60

20

0

180 120 240 0

13

(02 marks)

iii) Calculate the displacement of the car during the first two minutes using the graph.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (01 mark)

iv) Calculate the total displacement of the car during the four minutes. (01 mark)

D. As shown in the figure, the spare wheel of the vehicle is fixed

underneath the vehicle using two vertical nails ‘P’ and ‘Q’.

i) Under how many forces does the sparewheel remain in

equilibrium?

. . . . . . . . . . . . . . . . . . . . . . . . .

ii) An object can remain in equilibrium under the influence of three inclined forces. What

requirements are needed for the above condition?

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (01x2 marks) . .

Part B - Essay

Write answers for 3 questions.

spare wheel

P Q

14

5. Given below is the excretory system.

A. I. Name the parts labelled as A, B, C and D in the diagram. (02 marks)

11. Explain the flow of oxygenated blood from the right auricle to the kidney using a flow chart.

(02 marks)

III. State two human excretory material. (02 marks)

IV. State two functions performed by the kidneys. (02 marks)

B. I. What is the type of tissue present in ‘C’ in the above diagram.

(02 marks)

II. State two differences between the type of tissues in ‘C’ and the cardiac tissues. (02

marks)

III. State an excretory material that contains nitrogen. (02 marks)

IV. How does human excretory material differ from faeces? (02 marks)

C. I . Name two diseases associated with the digestive system. (02 marks)

II. State the cause for one of the diseases you mentioned above. (01 mark)

III. State the behavioural act that can be followed to prevent the above mentioned disease.

(01 mark)

6)

A . The figure given below shows a blast furnace used for iron extraction.

A

B

C

D

15

I. In addition to haematite and limestone, mention other material that is inserted into the blast

furnace. (1 mark)

II. According to the posion of Fe in the activity series, what is the method that is used to extract Fe

? (1 mark)

III. Write the balanced equation for the reaction of haematite during the process of iron extraction

under the above method.

(02 marks)

IV. Calculate the molar mass of Fe2 O3 ( Relative Atomic Mass Fe=56, O=16 ) (02 marks)

B I. Is the dissociation of limestone endothermic or exothermic? (1

mark)

II. Give reasons for your answer. (1 mark)

III. Draw the enthalpy diagram for dissociation of CaCO3. (02 marks)

IV. Dissociation of limestone produces CO2.

(a) Write the other chemical compounds used with CaCO3to produce CO2. (1 mark)

(b) Write a physical property of CO2. (1 mark)

C

I. The chemical formula of limestone is CaCO3. Draw a diagram to show the arrangement of

electrons in a Ca atom. (2 marks)

II. Mg and Ca belong to the same group in the periodic table. What is the valency of Mg? (02

marks)

III. Write the observation when a drop of phenolphthalein is added to the product obtained from

burning Mg in air. (02 marks)

Heamatite, limestone

Slag

Molten iron

16

IV.How does the first ionisation energy vary from left to right across the period in which Mg is

placed in the periodic table. (02 marks)

07)

A. A driver stays stationary under water at a depth of 2 m.

I. Calculate the pressure created on the body of the diver by water. (02 marks)

(Density of water = 1000 kg m-3 , g = 10 N kg-1)

II. What is the volume of water displaced by the driver, if the total volume of his body is 0.05 m3

?

(01 mark)

III. What is the upthrust acting on him? (02 marks)

B. Water flows from a reservior to a power station situated below it. The difference between water

levels is 20 m.

I. What is the potential energy of 1 kg of water in the reservior? (02 marks)

II. If the above potential energy is totally converted to knetic energy at the turbine, find the

velocity of water. (02 marks)

III. The supply voltage of a simple electricity generator is 100V and 5 A current passes through its

external circuit. Find the equivalent resistance of the system. (02 marks)

IV. If two resistors in a parallel combination are used instead of the above resistor, what is the

current obtained by the generator? (02 marks)

C.

I. Write the relationship between the output energy and the input energy there is no energy loss.

(02 marks)

II. What the numerical change of the current in a step down transformer when the secondary

voltage of it has been reduced to half of the primary voltage? (01 mark)

D The figure given below shows a circuit with a silicone transistor, two completely identical bulbs;

B1 and B2 and two completely identical swithches; S1 and S2.

B2

sS2

B1 S1 S1

17

I. When the switch S2 is closed, should the switch S1 be kept opened or closed to light the bulb

B2?

(01 mark) II. Which bulb contains more brightness? (01 mark)

III. What happens to LED in the following circuit when light falls and does not fall on LDR?

(1 mark)

LED

R

LDR

IV. What happens when the device R and LDR are inter changed? (1 mark)

08.

A. I. What is homeotasis? (1 mark)

The diagram given below shows how blood is supplied to the skin through blood vessels and

capillaries.

Ii. What changes are occured in the functioning of the cross blood vessels A and B, on a day

when the environmental temperatare gets higher and when it gets lower? (02 marks)

iii. How do the above contribute to maintain the body temperature constant? (02 marks)

Iv In addition to regulation of temperature, write two other instances in which homeotasis is

regulated. (02 marks)

B. i. What is the normal body temperature of a human? (1 mark)

18

ii. The body temperature of a sick person is 38 0C. The specific heat capacity of blood is 4200 J

kg-1 0C-1 . Calculate the amount of heat that should be liberated to reduce the temperature of 100 g of

blood to 37 0C. (03 marks)

C. The following diagram shows a clinical thermometer used to measure the temperature of the

human body.

X

i. What is the reason for the constriction at ‘A’ (1 mark)

ii. Write an advantage of using mercury as a thermometer liquid. (1 mark)

iii. On a hot day, the body temperature decreases due to the evaporation of sweat. What is the

scientific principle activated in the above incident? (2 marks)

iv. A mercury blood pressure meter is used to measure the blood pressure of a person. The

blood pressure is measured by the height of the mercury column. The blood pressure of a

person is 80/120 mmHg. The density of mercury is 13600 kg m-3 . Calculate the maximum

pressure difference in his blood vessels in Pascals. (3 marks)

D. Three hydrometers are submerged in the following liquids.

a kerosene b. water c. sea water

Write the depth that the hydrometers are immersed in each of the liquid in the ascending

order. (2 marks)

9) The figure given below shows a setup arranged to produce H2 in the laboratory.

H2

තසල

පනලය

කේත පලාසකව

B

A

වාය සරාව

19

A I. Name ‘A’ and ‘B’ in the above which are added to the conical flask. (2 marks) II. Write the balanced chemical equation for the production of H2 (2 marks)

III. Write two properties of H2gas. (2 marks) IV. Write two isotopes of H2 (2 marks)

B The diagram below shows how a balloon filled with H2 is connected to the ground by a string.

I. What are the forces that act on the balloon? (2 marks)

II. What connection should exist among the above forces, for the balloon to be in equilibrium?

(2 marks)

III. When the string is cut, the balloon moves up. Explain the reason for the above, in association

with forces mentioned earlier.

(2 marks)

IV. What is the Newton’s law that can be used to explain the above phenomenon? (2 marks)

C If the mass of the balloon is 30 g and the upthrust on the balloon is 0.4 N, considering the instance

that the string is cut;

I. Calculate the resultant force acting on the balloon. (2 marks)

II. Calculate the acceleration of the balloon moving up. (2 marks)

20

Answers

1. 1.

2. 2

3. 3

4. 3

5. 2

6. 4

7. 3

8. 3

9. 3

10. 3

11. 4

12. 2

13. 3

14. 3

15. 4

16. 1

17. 3

18. 3

19. 1

20. 3

21. 3

22. 3

23. 1

24. 1

25. 3

26. 3

27. 4

28. 3

29. 4

30. 4

31. 3

32. 2

33. 2

34. 3

35. 3

36. 3

37. 1

38. 1

39. 2

40. 1

21

Answer Guide

G.C.E. O/L Model Question Paper 01. A. i. 01mark

ii. Energy, Water, mineral ions 02 marks B. i. A 01mark ii. Any of the above trophic levels 01mark iii. Depletion of energy / heat 01mark iv.10% of energy flows from one trophic level to another 01mark C. i. The quantity of energy contains in “s” is 3 Kcal 01 mark ii. The amount of energy is very low when it reached to the 4th trophic level. When 10% of the energy flows from the fourth to the fifth trophic level, It is a minute amount. Therefore the links in a food chain is limited to

Maximum four. 01 mark

D. i. √ 1.5 marks

ii. x 1.5 marks

iii. x 1.5 marks

iv. √ 1.5 marks

15 marks 02. A.i. The tissues are composed of different types of cells and therefore modified to perform specific

functions 01 mark ii.a. water, minerals

b. Sucrose, Amino acid, growth hormone 03 marks iii. Mitosis 02 marks B.i. When producing pollens four cells are formed at the end of one cell division. When the cells in phloem tissues are divided, two cells are formed. The cells formed when producing pollen, contain half the number of chromosome in the mother cell. When the cells of phloem tissue are divided, they get the same number of chromosomes in the mother cell

02 marks ii. mitosis meiosis

More identical plants can be obtained Cannot be obtained so 04 marks iii. i. RR , Rr

ii. rr 01mark iv. i. Rr , rr

ii. Ratio of red to white is 1:1. 02 marks

15 marks

Unit

Uඒකක

ය

Community Eco-system

22

03. A. i. Flat bottom flask Libque condenser 02 marks ii. Since the aluminium tube gets heated quicker, the heat lost quickly, producing

cinnamon oil as a liquid 01 mark

iii. citronella leaves / cloves etc any suitable material 01 mark

iv. Heterogeneous mixture 01 mark B. i. mass fraction of the mixture 20g

100g + 20g 02 marks ii. covalent bond 01 mark iii.

02 marks iv. 6.022x 10 23 01 mark

C. i. 118 gmol-1 02 marks ii. 3 moles 02 marks 15 marks 04. A.i. Since an unbalanced external force is not applied on it. 01 mark ii. Y- The force exerted by the tyre on ground 01 mark

x – The force exerted by the ground on tyre 01 mark iii. similar in magnitude and opposite in direction 01 mark

iv. magnitude = 700- 300 =400N, Direction – forward horizontally 02 marks

B. i. moment of force = 20 x 0.8 =16 Nm 01 mark

ii. 16Nm = Fx0.4 = 40N 01 mark C. i. acceleration = change of velocity / time = 30 -0 /120 =0.25 01mark ii. Velocity (V) 30 Time ( S ) 120 240

02 marks

23

. iii. Displacement = ½ x 120 x 30 = 1800 m 01 mark

Displacement = 1800 + 120 x 30 = 5400 01 mark D. i. Under three forces 01mark ii. The resultant force of two inclined forces should be equal to the remaining force in magnitude and opposite in direction on the same line 01mark

15 marks 05.

A.i. A- Left kidney

B- Ureter C- Urinary Bladder

D- Urethra

02 marks

02 marks

iii. Urea, CO2, Creatinine, Uric acid, excessive water 02 marks

iv. Producing urine, water regulation, regulation of iron, concentration 02 marks

B i. Smooth muscles 02 marks ii. smooth muscles are un branched cardiac muscles are branched smooth muscles don’t have cross striation cardiac muscles have cross striation smooth muscles are neurogenic

cardiac muscles are myogenic 02 marks iii urea, uric acid, creatinine 02 marks iv Excretory products are results of metabolic activities inside the body. Excretory products can be harmful. Feces are undigested food particles 02 marks

C i Gastritis , constipation 02 marks Ii Gastritis – is a result of excessive release of HCl in the stomach, starving, mental stress, tuberculosis

Constipation – feces become solid 01 mark iii To control gastritis – maintain good mental health maintain good food habits To control constipation – drink plenty of water ( adequate amount ) Take food rich with fiber

01 mark

Right atrium Right ventricle Pulmonary artery

artery

kidney

Left atrium

Renal artery

Left ventricle

Avota Pulmonary veins

Lungs

24

Reactants

Products

6 (a)

i Coke/Carbon

ii reduction

iii fe203+3C0------------------- 2Fe + C02 20 marks

(b)

I Endothermic

ii because hear is absorbed in the process of dissociation of limestone.

iii

Iv. a. Diluted acid (HCL/H2S04)

b. Non supporter of combustion/density is higher than that of normal air.

(C)

i. Correct diagram

ii Valency is two

iii.The solution becomes pink

iv.increase till 4th batch and decrease from 5th batch

07.

(a) i. P = hpg

25

= 2x1000x10

=20000N/20KN

ii.0.05m3

iii. 0.05x1000x10=500N

(b)

i. Potential energy = mgh

= 1 x 10 x 20 = 200Nm/J

ii. 200 = ½ mv2 = ½ x 1 x v2

v = 20ms-1

iii. V = IR

100 = 5R

R = 20 Ω

iv. Equivalent resistance of two 20 Ω parallel resistance = 10 Ω

100 = 10 I

I = 10 A

(c)

i. Input power = output power

ii. V₁ I₁ = V₂I₂ (d)

I. S₁ should be closed

ii. In the bulb B₂ iii. 0.6/0.7

iv sensitive to light

08.

(a) i. Maintenance of the constant internal environment independent from external and internal

environmental conditions.

ii. As the blood vessel “B” is constricted and it’s diameter is decreased, the blood vessel “A”

isdilated and its diameter is increased on a hot day.

iii. Since the diameter of the blood vessel “A” increases more blood to flow across “A”

as these blood vessels are closed to outer skin the heat is lost through the process of radiation.

iv. Glucose, Iron concentration.

(b) i. 37 C

ii. Q = mcɸ Q= 100/ 1000 x 1 x 4200 = 420J

(c) i. To avoid falling back of the raised mercury level when the thermometer is taken away from the

body.

26

ii. any suitable answer

iii. As heat is used in evaporation of sweat from the body.

iv. 120/1000 x 13600 x 10 = 16320 pa

(d) i. Sea water, water and kerosene oil.

09.

(a) i. A - Zn/Al particles of pieces.

B – Diluted acid Hcl/ H₂S0₄

ii. Give marks for the correct equation

iii. Light, odor less or any correct answer

iv. 2₁H, 3₁H

(b) i. Tension of the string and the up thrust

ii. Tension of the string and up thrust should be equal and opposite

iii. As the up thrust is greater than the force acting towards the ground.

iv. Newton’s Laws

(c) i. 0.03 x 10 = 0.3

ii. 0.1 N (0.4 – 0.3)

F = ma

0.1 N = 0.03 x a

0.1/0.03 = a

a = 10/3 = 0.33ms-1