SHULE YA UPILI YA WAVULANA CHINGAKAZI YA LIKIZO KISWAHILI KIDATO CHA NNE 2020

Soma hadithi zote zilizobakia za hadithi fupi (Tumbo lisiloshiba) na uchambue kwa undani (wahusika, maudhui, ploti na lugha.)

CHINGA BOYS HIGH SCHOOLAPRIL HOLIDAY ASSIGNMENT 2020HISTORY AND GOVERNMENT FORM FOUR

Read and make notes on the following topics:

1. Social economic developments and challenges in Kenya.2. Political, economic and social challenges in Africa (DRC and Tanzania).3. Electoral processes in the world (US, BRITAIN and INDIA).

CHINGA BOYS HIGH SCHOOLAPRIL HOLIDAY ASSIGNMENT 2020CRE FORM FOUR

INTRODUCTION TO CHRISTIAN RELIGIOUS EDUCATION PAPER 11. Explain the different ways in which Christians in Kenya use the bible to

spread the Good news.

2. Give the consequences of sin according to genesis 3:11

3. What are teachings of the Genesis stories of creation?

4. Give five reasons why reading the bible is important to Christians.

5. Explain the different ways in which Christians in Kenya use the bible to

spread the good news.

6. Identify five responsibilities given to human beings by God in the Genesis

stories of creation

7. a) State the responsibilities given to human beings in Genesis Chapter

1 and 2.

b) Outline the lessons that Christians learn about work from the Genesis

stories of creation.

c) How can Christians care for God’s creation today?

8. a) Give reasons why Christians read the Bible.

b) With reference to the Genesis stories of creation in Chapter 1 and 2 outline

the attributes of God.

c) What are the consequences of breaking taboos in traditional African

Communities?

9. a) Outline the differences in the two accounts of creation in Genesis 1 and 2.

(10 mks)

b) From the story of the fall of human beings in Genesis chapter 3, state the

effects of sin. (6 mks)

c) Identify any four causes of evil in Kenya today. (4mks)

10. a) Give reasons why the Bible is referred to as a library (5mks)

b) Outline five effects of the translation of the Bible into local

Languages. (10mks)

c) State five ways through which the church is spreading the

word of God in Kenya. (5mks)

11. Identify the books referred to as the Apocrypha.

12. Explain the effects of the bible translation into African languages in Kenya

13. State the various occasions during which the bible is used in Kenya.

14. Explain the problems Christians face in the work of evangelization.

15. Identify the literacy forms used in the bible

16. State the Biblical causes of sin.

17. Why is it important for Christians to obey god?

18. State ways in which Christians use the print media to spread the gospel

19. What makes man the most important of all that was created by God?

20. State the problems faced by Bible authors.

CHAPTER TWO

FAITH AND GOD’S PROMISES

DEFINITION OF FAITH

1. Describe ways in which Abraham demonstrated his faith in God

2. Outline the promises of god to Abraham

3. Describe five actions from the life of Abraham which show his faith in God.

4. List five animals used in making of the covenant between God and

Abraham.

5. State the promises that God and Abraham

6. a) State the characteristics of the covenant between God and Abraham. (10mks)

b) Explain the importance of God’s covenant with Abraham. (10 mks)

c) What lessons do Christians learn from the incident when Abraham was

willing to sacrifice his son Isaac? (5mks)

7. Describe the covenant between God and Abraham

8. Identify the circumstances under which covenants were made in the traditional

African society.

9. Name five modern covenants

10. What was the importance of the covenant made between God and Abraham?

11. Name any three covenants made in the Old Testament.

12. Why Abraham is called the father of faith?

13. Explain the importance of circumcision of Abraham and his descendant

14. From the Mt- Mariah experience explain what Abraham and his descendant

15. From the Mt-Mariah experience explain what Abraham learnt about God’s nature

16. Narrate the call of Abraham

17. What can Christian learn from the call of Abraham?

CHAPTER THREE

MOSES AND THE SINAI COVENANT

1. Outline the qualities of god learnt by the Israelites during the making of the

Sinai covenant.

2. Describe ways in which God demonstrated his mercy to the Israelites at Mt.

Sinai

3. Explain the stages followed in the making of the Sinai covenant.

4. List the qualities of Moses shown during his call at Mt. Sinai

5. Identify five lessons that Christians learn about God from the call of

Moses.

6. State five ways in which God revealed himself to the Israelites at Mt.

Sinai.

7. Give the values that a Christian can learn from the call of Moses.

8. Describe how the Israelites worshipped God before the Babylonian exile.

9. Explain the conditions given to the Israelites during the renewal of the

Sinai covenant.

10. State five ways in which God’s power is demonstrated in the deliverance of

the Israelites from Egypt to the promised land.

11. Give five lessons why Moses was not willing to go back to Egypt after his

call.

12. List five commandments given to the Israelites that teach on how to relate

to one another

13. What problems did Moses face as he led the Israelites during the Exodus?

14. a) Outline the activities carried out by the Israelites on the night of the Passover.

(5 mks)

b) Give five reasons why the exodus was important to the Israelites.

(10mks)

c) How do Christians show their respect for God? (5 mks)

15. Give the events which took place on the night of the Exodus.

16. Give similarities between the Jewish Passover and Christian Easter

17. Identify ways in which the Israelites showed lack of faith during the Exodus.

18. Describe ways in which Moses showed his obedience to God

19. Give ways in which the Israelites disobeyed the Ten Commandments.

20. Give lessons why God made a covenant with the Israelites at Mt. Sinai

21. Explain what the Israelites understood about God from the Exodus experience.

22. Why should Christians live by the laws of God?

23. Describe the call of Moses.

CHAPTER FOUR

LEADERSHIP IN ISRAEL

1. Explain ways in which injustice can disrupt peace in society.

2. Give five activities of King Jeroboam that made the Israelites in the

Northern Kingdom turns away from God.

3. Give reasons why the Northern Kingdom of Israel was destroyed before the

Southern Kingdom of Judah.

4. Identify five ways used by the Israelites kings to bring people back to God

5. Explain the duties of Prophet Samuel

6. Explain the factors that led to the failure of David’s successors.

7. Explain the failures of King Saul

8. Give reason why the Israelites demanded for a king

9. State the achievements of Solomon as king of Israel.

10. In what ways did David’s promote the worship of god?

11. Explain why Samuel was opposed to kingship in Israel.

12. Explain why David was the most successful king in Israel.

13. Explain the importance of the temple in Jerusalem in the religious lives of the

Israelites.

14. State the role of Judges in Israel.

15. Outline the promises given to King davit

16. Discuss the qualities modern leaders should have form the example of David.

17. Explain how King Solomon turned away from the covenant way of life .

18. Name nine Judges in Israel.

19. Explain five challenges that the Israelites faced during the period of Judges.

CHAPTER FIVE

LOYALTY TO GOD: ELIJAH

THE SPREAD OF IDOLATRY IN ISRAEL

1. What circumstances led to the contest between Prophet Elijah and the

Prophets of Baal at Mt. Carmel?

2. Explain the circumstances which led to the spread of idolatry in Israel

3. What were the characteristics of the Canaanites religion?

4. State five challenges that prophet Elijah faced in Israel

5. Describe the problems faced by prophet Elijah in Israel.

6. State five practices of idolatry during the time of Prophet Elijah

7. a) Describe the nature of the Canaanite religion. (10 mks

b) Identify ways in which King Jeroboam contributed to religious schism

between Judah and Israel. (4 mks)

c) What life skills do Christians need to use in order to fight corruption in

Kenya today? (6 mks)

8. a) Describe the contest between prophets of Baal at mount Carmel

(1st Kings 18:17-40). (7mks)

b) Give four conditions that made it difficult of Prophet Elijah to stop idolatry in Israel. (8mks)

c) Identify five qualities of Prophet Elijah that a Christian leader should possess. (5mks)

9. What did the Israelites learn about the nature of God from the Mt.Carmel

Contest?

10. List down some forms of corruption in our society today.

11. Name the signs used by God to show his power over Baal’s during the time of

Elijah.

12. In what ways did Jezebel and Ahab break the covenant way of life in Naboth’s

case?

13. Why is idol worship condemned in the Old Testament?

14. What is the relevance of Elijah’s prophetic mission to the Christians today?

15. Give reasons why Elijah was forced to escape from Israel.

16. Identify the lessons one would learn from Mt. Carmel contest.

17. Identify seven forms of idolatry that threaten Christianity today.

18. Identify and explain three life skills that Elijah used to fight corruption in Israel.

CHINGA BOYS HIGH SCHOOL

FORM 4 ASSIGNMENT TERM 1 2020 BUSINESS STUDIES

Instructions: IN ADDITION TO THE ASSIGNMENT GIVEN; READ AND WRITE NOTES ON:

1. The remaining part of ECONOMIC PLANNING if there was any2. INTERNATIONAL TRADE:

a) Definition of international trade b) Advantages and disadvantages of International tradec) Terms of trade: i) Definition

ii) Computation of terms of trade iii) Factors determining terms of trade between countries iv) Reasons for differences in terms of trade between countries

v) Favorable and Unfavorable terms of trade

d) Balance of payment: i) Definition ii) Balance of payment account iii) Components of balance of payment account

iv) Balance of payment disequilibrium; Causes of balance of payment deficit and surplus v) Correcting balance of payment disequilibrium

CHINGA BOYS HIGH SCHOOL

APRIL HOLIDAY ASSIGNMENT 2020

CHEMISTRY FORM FOUR

MODEL 1 PAPER ONE 233/1

1. The table below shows the pH values of solutions J to N

Solution J K L M N

pH 5 13 2 10 7

a) Which solution(i) Contains the largest concentration of hydroxides ions ½mks

(ii) Is likely to be a solution of acetic acid? ½mks

b) In the equation below, identify the reagent that acts as an acid in the forward reaction.

Give a reason. 2mks

NH4+

(aq) + H2O(l) NH3(aq) + H3O+(aq)

2. Study the diagram below and answer the questions that follow. The diagram shows the method used to separate components of mixture Q

a) Name X and Y 1mk

b) What is the purpose of apparatus X? 1mk

c) Show on the diagram the direction of flow of cold water used for cooling the vapour formed.

1mkd) What name is given to the above method of separating mixtures? 1mk

3. Explain using chemical means how you will differentiate between carbon (II) oxide and carbon(IV) oxide. 1mk4. An unknown mass of anhydrous potassium carbonate was dissolved in water and the solution

made up to 200 cm3. 25 cm3 of this solution neutralized 18.0 cm3 of 0.22 M nitric (V) acid.

Calculate the unknown mass of potassium carbonate. (K=39, C=12, O = 16) 3mks

5. Study the diagram below and answer the questions that follow.

a) State any two observations made during the experiment. 2mks

X

Liquid mixture Q

Heat

Y

Thermometer

Carbon electrodes

CuSO4(aq)

b) What is the likely pH of the resultant solution at the end of experiment? 1m

6. When magnesium ribbon is burnt in air and the product dissolved in water, a colourless

solution is formed and a colourless gas is evolved.

(i) What effect does the solution formed have on litmus paper? 1mk

(ii) Name the compound responsible for the production of the colourless gas. 1mk

(iii) Write down a balanced chemical equation for the reaction producing the colourless gas. 1mk

7. The table below gives some properties of substances G H I and J. Study it and answer the

questions that follow.

Substance

Solubility in water Electrical conductivity

M.Pt 0C

B.Pt

0CSolid state Liquid state

G

H

I

J

Insoluble

Slightly soluble

Soluble

Insoluble

Doesn’t conduct

Doesn’t conduct

Doesn’t conduct

Conducts

Doesn’t conduct

Doesn’t conduct

Conducts

Conducts

High

Low

High

High

High

Low

High

high

a) Select the substance which is likely to be copper metal. Give reason. 1 ½ mk

b) What type of bond structure exists in substance G? Give a reason. 1 ½ mk

8. a) Name the cleaning agent shown below. 1mkR

O SO-3Na+

b) State one disadvantage of continued use of the above cleaning agent. 1mk

9. Give two reasons why a luminous flame is not used for heating purposes. 2mk

10. Calculate the oxidation number of nitrogen in the following species.

NO3- 1mk

NH3 1mk

11. On completion combustion in oxygen a gaseous hydrocarbon x gave 1.32g of carbon (iv) oxide and 0.54g of water. Calculate the empirical formula of x (C=12.0, H=1, O=16.0)

12. The following is an organic compound represented as CH3CH2COOCH2CH3

(i) Determine the organic acid and the alkanol used in its making (1mk)

(ii)Name the organic compound and the gas formed when the alkanol in (i) above is reacted with potassium metal. (1mk)

13. The following is a nuclear equation

233 x

Pa AC +

91 ya) Calculate the value of x and y 1mk

b) State two differences between a nuclear reaction and a chemical reaction. 2mks

14. Describe how you would prepare a dry sample of lead (II) chloride starting with lead (II) carbonate. 3mks15. Use the information to answer the questions that follow.

C (s) + O2(g) CO2 (g) H1 = -393 kJ mol-1

H2 (g) + ½ O2 (g) H2O (l) H2 = -286 kJ mol-1

C4H10+ 6 ½O2 (g) 4CO2 (g) + 5H2O H3 = -2877 kJ mol-1

a) Define the term molar enthalpy of combustion of a compound 1mk

b) Calculate the molar enthalpy of formation of butane C4H10 from its elements in their normal states at standard temperature and pressure. 2mks

16. When calcium carbonate was added to a solution of dry hydrogen chloride in methyl benzene

there was no observable reaction. Explain. 2mks17. The following elements belong to the same group of the periodic table. (letters do not represent the actual symbols)

Element Atomic radii (nm) Ionic radii (nm) First ionization Energy KJ mol-1

A 0.136 0.065 736

B 0.089 0.031 900

C 0.174 0.099 590

(i) Are the elements metals or non-metals? Explain 1mk

(ii) Which of the elements is the most reactive? Explain. 1mk

18. a) What is observed when hydrogen sulphide gas is bubbled into lead (II) nitrate solution? 1mk b) Write an ionic equation for the reaction. 1mk19. Below are standard reduction potentials of 3 electrodes.

Fe2+ (aq) + 2e- Fe (s) - 0.44v

Zn2+ (aq) + 2e- Zn (s) - 0.76v

Sn2+ (aq) + 2e- Sn (s) - 0.14v

Explain using electrode potentials why an iron coated with tin will rust when scratched. But one coated with zinc will not rust when scratched. 2mks20. Bromine dissolves in water forming a brown solution, according to the dynamic equilibrium

equation below.

Br2 (aq) + H2O(1) 2H+(aq) + Br-

(aq) + OBr-(aq)

State and explain the observation that could be made if a solution of sodium hydroxide is

added to the system. (2mks)

21. Below is a sketch of the volume against time for a reaction between magnesium ribbon and

2M HCl.

a) State two ways in which the rate of the production of the gas would be increased. (2mks)

b) On the same diagram, sketch the graph that would be obtained with same quantity of

magnesium ribbon and 4M HCl. (1mk)

22. The figure below shows a paper chromatogram for a pure substance W.

(i) What is chromatography? (1mk)

Time (mins)

Volu

me

(cm

3 )

(ii) Given that W contains blue and green dyes, show the chromatogram of W on the

diagram. (2mks)

iii) Explain why the Red spot moves further than that of blue and green. (1mk)

23. An element P has a relative atomic mass of 88. When a current of 0.5 Amperes was passed through the fussed chloride of P for 32 minutes and 10 seconds, 0.44g of P were deposited at the cathode. Determine the change of an ion of P (1 Faraday = 96500 coulombs) (3mks)

24. How would you distinguish the following compounds; CH3COOH and CH3CH2OH?

(2mks)

25. Using dots (.) crosses (x) to represent outermost electrons, show bonding in the compound formed between elements W and X with atomic number 14 and 17 respectively. (2mks)

26. The flow chart below shows the preparation of carbon (II) oxide and its reactions.

Oxalic acid

H2C2O4

Gaseous Conc

Mixture KOH

Conc.

H2SO4 PbO

Gas C B

a) (i) Name the type of reaction taking place between H2C2O4 and conc. H2SO4. (½mk)

(ii) Why is gaseous mixture passed through conc. KOH? (1 mk)

b) Write an equation for the production of B and C. (1mk)

c) State two uses of carbon (II) oxide. (1mk)

27. Below is a portion of Perspex polymer.

H CH3 H CH3 H CH3

C C C C C C

H COOCH3 H COOCH3 H COOCH3

a) Draw the structural formula of the monomer. (1mk)

b) State one use of the polymer. (1mk)

c) State two advantage of Perspex over natural polymers. (1mk)

28. Explain why it is not suitable to prepare hydrogen gas using dilute nitric (V) acid and zinc metal. . (2mks)29. The ions T3+ and U-3 have identical electronic configuration. T is in period 3.

i) Write the electronic arrangement of the elements (2mks)

T _______________________________________________________

U _______________________________________________________

ii) Write the formula of the compound formed when T combine sulphur (S = 16.0) (1mk)

30. Explain this observation. When burning magnesium is lowered into a gas containing carbon (IV) Oxide gas, it continues to burn but a burning splint goes off. (3mks)31. A fixed mass of a gas occupies 140cm3 at a temperature of 220C and 740 mmHg pressure. Calculate the volume at S.T.P (2mks)

MODEL 1 PAPER TWO 233/2

1. The grid below is a section of the periodic table. The letters are not actual symbols. Use it to

answer the questions that follow.

X Z M

R Y A

Q D

(i) How do you compare the melting points of R and Y? Explain. (1mk)

(ii) Which element has the lowest ionization energy. (1mk)

(iii) Basing on structure and bonding, state the structure in

(a) Z (½mk)

(b) Chloride of Y (½mk)

( c) Oxide of Q (½mk)

iv) State the nature of

a) Oxide of R. (½mk)

b) Oxide of A. (½mk)

v) Choose the letter representing an element that

a) Is the most electronegative. (½mks)

b) Exists as a mono-atomic gas. (½mk)vi) a) Nitrogen falls in the same group as A. Write the formula of the compound formed when A reacts with magnesium. (1mk)b) Write a balanced equation for the reaction between the compound in (a) above and water. (1mk)vii) a) Name the two physical forms of element Z that are crystalline. (1mk)b) Which one of the two forms in (a) above is

I Suitable for use as a lubricant. (½mk)

II Suitable for use in making drilling implements. (½mk)

viii) State the general property common to elements in the group containing D. Explain.

(1mk)ix) Put a tick () in the position of an element E that has four energy levels and forms a chloride ECl4 (½mk)x) a) Write down the electronic configurations for x. (½mk)

b) Compare the atomic radius of X to its ionic radius. (½mk)

2. The reaction scheme below has glucose as the starting material.

Glucose

Process L

Crude Ethanol

Process K

A Conc. H2SO4 H+ (aq) MnO4-(aq) B Na(s)

180 oC Pure Ethanol

Gas V

Process M Ethanol

followed by a few

drops of conc.

sulphuric acid then

warm

Ethane C

a) Identify substances labeled; (1mk)

A……………………………………………………………………………………………

B……………………………………………………………………………………………

b) Give the name of the processes labeled (1mk)

L……………………………………………………………………………………………

K……………………………………………………………………………………………

c) Identify the reagent and conditions necessary for the process M. (2mks)

Reagent

Condition

d) Write the structural formula of substance C. (1mk)

e) To which homologous series does substance A belong. (1mk)

f) Write an equation for the reaction between B and sodium metal forming substances W

and gas V. (1mk)

g) What is observed when a few drops of Bromine water are added to a small sample of

substance A? Explain your answer. (2mks)

h) Give one industrial application of process M. (1mk)

3. Two half cells were connected as shown to form a voltaic cell. The reduction potentials are

given.

Pb(aq )2+ + 2e→ Pbs Eθ =−0.13V

Fe(aq )2+ + 2e→ Fe( s ) Eθ =−0 . 44V

(a) Calculate the e.m.f of the cell. (1mk)(b) Write down two functions of the salt bridge. (2mks)(c) Show the direction of the electron flow in the external circuit.

(1mk)

(d) The e.m.f of the cell will reduce with time. Give a reason for this. (1mk)(e) During electrolysis of water acidified with Sulphuric acid, two gases were

produced at the electrodes:(i) State which ions are preferentially discharged at the electrodes. Explain

with aid of half ionic equations.Anode (2mks)

Cathode (2mks)

(ii) Calculate the volume of the gases at S.T.P. produced when a current of 0.025A is passed for 4 hours. (1 Faraday = 96500 C (3mks)

4. Aluminium is the most abundant metal in the earth’s crust (8.3%).It is produced by electrolysis of Aluminium oxide after preliminary treatment. Study the diagram and answer the following questions.

(a) (i) Name the main ore used. (½mk)

(ii) State the materials used in making; (1mk)

P…………………………………………………………………………………..

Q………………………………………………………………………………….

State the reason why Q is frequently replaced during extraction of

Aluminium. (1½mks)

(iii) State two activities that are done to the ore to improve its property as an electrolyte. Explain. (2mks)

(b) Extraction of Zinc and lead are usually done at the same time.

(i) Name one main ore of ;

Zinc………………………………………………………………………... (½mk)

Lead………………………………………………………………………... (½mk)

(ii) Name two reducing agents used in the blast furnace during roasting/extraction of Zinc and Lead. (1mk)

(iii) Write down the equation during the reduction of ZnO or PbO, using any of the reducing agents in (b) (ii) above. (1mk)

(c) (i) State one use of Lead

……………………..…………………………………………………..... (½mk)

(ii) What is galvanization……………………...……………………………………………………. (½mk)

5. a) The set up below represents the arrangement used to prepare substance S by passing a

stream of dry hydrogen chloride gas over heated iron wool.

(i) Correct the mistake in the set up above. (1mk)

(ii) Give the chemical equations for the reaction that involves the formation of substance

S. (1mk)

(iii) The reaction at point x. (1mk)

(iii) What precaution would you take when carrying out this experiment? Give reasons.

(2mks)

b) 300cm3 of hydrogen chloride gas were passed over 7.0g of heated iron wool until

there was no further change. The reaction vessel then was allowed to cool to room

temperature

(i) Determine the mass of iron that remained at the end of the experiment.

(Molar gas volume = 24000cm3, Fe=56). (2mks)

(ii) Determine the volume of 2M sulphuric acid that would be required to react with

excess iron that remained in the above experiment b(i) above. (2mks)

c) What would you observe when sodium hydroxide solution is added to the aqueous

solution of the product formed in (a) above. Explain. (2mks)

6. An experiment was carried out to determine the temperature changes when 2.0 cm3 portions

of 2.0 M of a certain acid were added to 20.0cm of 2.0M Sodium hydroxide solution. The

temperature changes were recorded in the table below. The initial temperature of the solutions

was 190C.

T Iron woolConc. H2SO4

Substance S

HEAT

W

NaCl

Conc. H2SO4

Volume of acid added (cm3) 0 2 4 6 8 10 12 14 16 18

Temperature 0C 19.0 21.0 23.0

25.0 27.0 28.0

29.0 26.0 22.5

19.5

(a) Plot a graph of temperature (vertical axis) against volume of acid added (3mks)

(b) Using the graph determine the;

(i) volume of acid needed for complete neutralization (1mk)

(ii) highest temperature rise during the reaction (1mk)

(c ) Calculate the number of moles at the neutralization point for the :

(i) Sodium hydroxide (1mk)

(ii) Acid (1mk)

(d) Deduce the basicity of the acid used in the experiment from your answer in (c) above. (2mks)

(e) Calculate the molar heat of neutralization of sodium hydroxide. Specific

heat capacity of the solution is 4.2 Jg-1K-1 and the density of the solution is 1gcm-3

(3mks)

(f) Name one source of error in an experiment like this. (1mk)

7. The flow chart below shows how nitric (V) acid is produced on a large scale. Study it and

answer the questions that follows.

Heat

Gas A Purifier Compressor exchanger Catalytic

Air Chamber (C)

Hot water

Absorption Reaction Purified Air

tower Chamber

a) State the functions of:

(i) Purifier (1mk)

(ii) Heat exchanger (1mk)

b) Identify

(i) gas A………………………………………………………………………….. (½mk)

(ii) gas B………………………………………………………………………….. (½mk)

(iii) Catalyst C…………………………………………………………………… (½mk)

c) Write equations for the reaction that take place.

(i) in catalytic chamber. (1mk)

(ii) in absorption tower. (1mk)

gas B

and

air

d) Calculate the molarity of the commercial nitric (v) acid, given that it is 68% pure and

has a density of 1.42g/cm3. (N=14, H=1) =16) (2½mks)

e) (i) Complete the table below to show the observations made when concentrated nitric

(V) acid is added to the substances shown and warmed.

Substance Observation

Acidified Iron (II) sulphate

Sulphur powder

(ii) Give reasons for the observations made using:

I Acidified iron (II) sulphate. (1mk)

II Sulphur powder (1mk)

BIOLOGY FORM FOUR HOLIDAY ASSIGNMENT- MARCH 2020.

RECEPTION, RESPONSE AND CO-ORDINATION

1. State one structural and one functional differences between motor and sensory neurons

2. The table below shows two mammalian hormones. For each hormone, state the site of

production and its function in the body.

Hormone Site of production Function

Oestrogen

Aldosterone

3.

(i) With an arrow, indicate on the diagram the direction of the impulse through the

neurone

(ii) State the functions of parts labeled P and Q ( 2 marks)

4. (a) How are structures of the human eye adapted to their functions ( 14 marks)

(b) State three defects of the eye and how each can be corrected ( 6 marks)

5. State the changes that occur in a nerve axon to produce an action potential

6. In an accident a victim suffered brain injury. Consequently he had loss of memory.

Which part of the brain was damaged? ( 1 mark)

7. The diagram below shows surface view of a human brain

(a) Name the parts labeled B and C ( 2 marks)

(b) State three functions of the part labeled A ( 3 marks)

(c) State what would happen if the part labeled B was damaged. ( 1 mark)

8. What is the function of the following cells in the retina of the human eye?

(a) Cones (b) Rods

9. (a) State the functions of the following parts of the mammalian ear

(i) Tympanic membrane (ii) Eustachian tube (iii) Ear ossicles

(b) Describe how semi- circular canals perform their functions ( 2 marks)

10. State the importance of tactic response among some members of Kingdom Protista?

(a) What name is given to response to contact with surface exhibited by tendrils and

climbing stems in plants? ( 1 mark)

(b) State three biological importances of tropisms to plants (3 marks)

11. The diagram below represents a reflex arc in human

(a) Name the parts labeled X and Y ( 2 marks)

(b) Name the substance that is responsible for the transmission of an impulse across the

synapse

12. (a) State the function of the ciliary muscles in the human eye. (1 mark)

(b) State two functional differences between the rods and cones in the human eye

13. State the function of each of the following parts of human ear ( 4 marks)

a. Ear ossicles (b)Cochlea (c)Semi- circular canals (d)Eustachian tube

14. (a) Where in the human body are relay neurons found? ( 1 mark)

(b) The diagram below represents a neurone

(i) Name the neurone ( 1 mark)

(ii) Name the parts labeled P and Q (

15. (a) Name the hormone that is responsible for apical dominance ( 1 mark)

(b) What is thigmotropism? ( 1 mark)

16. Describe the structure and functions of the various parts of the human ear( 20 marks)

17. Nocturnal animals such as the owl are capable of seeing fairly well at night

What two retinal adaptations have made this possible? ( 2 marks)

18. State two functions of the human ear? ( 2 marks)

19. State four differences between co- ordination of the human eye’s internal response to

light and that of tropic movement of the flowering plant in response to light.

( 4 marks)

20. The figure below shows a stem of a plant growing round a tree trunk

(i) What is the name of the response, which causes the twisted growth?

(ii) Explain how the twisting process is accomplished ( 2 marks)

(iii) Identify the state of leaves if the plant is autotrophic ( 2 marks)

21. Euglena is positively phototactic. Of what biological significance is this characteristics?

22. State the function of acetylcholine ( 2 marks)

23. Where in the human body is the relay neurone located? ( 1 mark)

24. State three effects of nicotine to human health ( 3 marks)

25. state the part of the eye involved in

(i) Colour vision (ii) Maintaining shape of the eyeball (iii) Change in diameter of

the lens

26. Discuss the importance of support and movement in: (a) Animals (b) Plants.

CHINGA BOYS HIGH SCHOOLHOLIDAY ASSIGMENT TERM 1 2020 COMPUTER STUDIES

SECTION A: (40 MARKS)

Answer ALL the questions in this section in the space provided.

1. (a) A computer laboratory should be constantly kept dust and smoke free. Specify two effects that dust would have on the operation of computers.(2 marks)

(b) Why should you first switch on the UPS before switching on the system unit and the monitor?

(1 mark)

2. Explain the meaning of backup.(2 marks)

3. State the following types of transcription errors.(2 marks)

(a) 3455 instead of 3456(b) Smith instead of simth

4. (a) State three ways used to represent a negative number.(3 marks)

(b) Perform the following binary arithmetic giving the answer in decimal notation.

1110.0111 + 1101001.011 (2 marks)

5. Distinguish between data privacy and data integrity as used in computing.(2 marks)

6. Differentiate between a primary key and a foreign key while designing a database. (2 marks)

7. Distinguish between ‘count’ and ‘countif’ functions as used in spreadsheets.(2 marks)

8. Match the following statements with repeater, router or a bridge. (2 marks)

STATEMENT DEVICE

(a) Operates at data link layer

(b) Determine the best path for data to

follow

(c) Regenerates signals

(d) Forwards everything which it

doesn’t recognize

9. Explain the impact of Information Technology on organization in each of the following

areas.(2 marks)(a) Competition.

(b) Pace of growth.

10. List two roles performed by system analyst.(2 marks)

11. Explain the following internet related terms.(4 marks)

(a) Sign IN

(b) Search engine

(c) Surf(d) Sign up

412. In Kenya Tea Packers Company, several people are employed as record clerks,

typists and messenger. The company intends to introduce a computerized system in all the departments. Suggest three reasons that would make workers unhappy with the new system. (3 marks)

13. State two magnetic Storage devices.(2 marks)

14. State three functions of Central Processing Unit.(3 marks)

15. For each of the following file organization methods, state an appropriate storage medium:

Start

Enter: N, M

= M: Y = N N, M

P = y - : Q = - y

P > Q?P = yQ = x

P = xQ = y

PRINT: P, Q, , y

Stop

No Yes

(2 marks)

(a) Serial

(b) Random5

SECTION B: (60 MARKS)

Answer question 16 (compulsory) and any other THREE questions from this section.

16. (a) Study the flowchart below and answer the questions that follows.

(i) State the name of the control structure shown in the flowchart.(1 mark)

(ii) Assuming the user keys in 8 and 14 when prompted to enter the values for m and N respectively, determine the printed values of P, Q, and y.(4 marks)

(iii) Write the pseudocode that would be used in place of the flowchart.(5 marks)

(b) What is the difference between looping and selection.(2 marks)

(c) Name the stage of program development cycle when:(3 marks)

(i) A user guide would be written.(ii) A programmer dry-runs the code.(iii) System charts would be drawn.

17. (a) What is Virtual reality?(1 mark)

(b) Explain the following interactive sensory equipment used in virtual reality.(2 marks)

(i) Head gear.(ii) Body suit.

(c) (i) What is Artificial Intelligence?(1 mark)

(ii) State and explain three components of an experts system.(6 marks)

(d) Most computerized security systems make use of Biometric analysis, name three physical features of human beings that can be considered in this analysis.

18. (a) Explain two coding schemes used in data representation techniques.(4 marks)

(b) Using one’s and two’s complement work out 14 – 9.(i) One’s complement.

(2 marks)(ii) Two’s complement.

(2 marks)

(c) Work out the hexadecimal equivalent of 1011111000112

(2 marks)(d) Identify the following types of ports.(5 marks)

19. (a) Explain two functions of an operating system.(4 marks)(b) Explain the following terms as used in disk management using operating

system:(i) Disk defragmentation.

(2 marks)(ii) Disk clean up.

(2 marks)(c) What will happen if you attempt to delete a folder while a file contained in

it is Open?(1 mark)

(d) State two properties that an operating system displays about a file.(2 marks)

(d) Give four advantages of storing files in folders.(4 marks)

20. (a) The diagram below shows four common network topologies A, B, C and D.

B

D

A

C

Server Terminal Printer

X

(i) Name the network topologies labeled A, B, C and D. (4 marks)

(ii) Explain what happens if server X in topology A fails. (1 mark)

(iii) List two problems associated with network topology B.(2 marks)

(iv) List two disadvantage associated with network topology labeled D.(2 marks)

(b) Differentiate between Internet and World Wide Web. (2 marks)

(c) Describe the following network services and identify their applications(4 marks)

(i) Voice mail.

(ii) Video conferencing.

CHINGA BOYS HIGH SCHOOL FORM 4 2020 DURING C19 PHYSICS ASSIGNMENT1. Figure 1 shows a micrometer screw gauge with a negative error of 0.02mm, used to measure the diameter of a ball bearing.

Record the diameter of the ball. (2mks)

2. Explain the washing effects of detergents of soap and why detergents in warm water wash greasy clothes even better. 3. Figure 2 below shows a u-tube containing two liquids L1 and L2 of densities 0.5gcm-3 and 0.8gcm-3 respectively floating on a water surface. If the system is in equilibrium, determine the whole number ratio of h1:h2. (2mks)

4. State two assumptions made when determining the diameter of an oil molecule in the oil drop experiment. (2mks)5. Sketch a density temperature graph for water being heated from 00C to 100C on the axes provided6. Explain why a shiny tea pot stays hotter longer than a dull tea pot. (1mk)7. Figure 4 below shows a uniform bar 2.0m long being at equilibrium under the action of the forces shown.

Determine the weight of the bar. (2mks)

8. Figure 5 below shows cambered wheels

What is the advantage of wheels? (1mk)9. Two identical helical springs are connected in series. When a 50g mass is hang at the end of the springs, it produces an extension of 2.5cm. Determine the extension produced by the same mass when the springs are connected in parallel10. A bathroom shower has 200 holes each 2.5mm2 in area. Water flows from a pipe of cross-section area of 15cm2 at 5 m/s to the shower. Determine the speed of the spray. (2mks)11. A body weighing 100N in air is found to weigh 80N when fully immersed in a certain fluid. Account for the difference in the two weights. (1mk)

12. A body of mass M kg moves uniformly round a circle of radius,r, with a linear velocity, V m/s. Derive an expression for the relationship between its Linear velocity V and angular velocity . (2mks)13. A partially filled balloon is placed in a bell jar with its open end on a flat glass plate as shown in the figure 6 below. The contact between the jar and the glass plate is greased to made it air tight.

State and explain what happens to the balloon when air in the bell jar is slowly evacuated. (2mks)

14. A car of mass 1000kg travelling at 36km/h is brought to rest over a distance of 20m. Find the acceleration of the car. 15. a) Define specific latent heat of vapourization. (1mk) b) In an experiment to determine the specific latent heat of vapourization of water, steam at 1000C was passed into water contained in a well lagged copper calorimeter. The following measurements were made:Mass of calorimeter.. 50g Initial mass of water. 70g Initial temperature of water. 50CFinal mass of calorimeter + water + condensed steam. 123g Final temperature of the mixture. 300CGiven that the specific heat capacity of water = 4,100j/kgk and specific heat capacity of copper = 390j/kgk, Determine:i) The mass of condensed steam. (1mk)ii) Heat gained by calorimeter and water. (2mks)iii) Write an expression for the total heat given out by steam. (2mk)iv) Determine the value of specific latent heat of vapourization. (2mks)16. a) State the law of conservation of energy. (1mk) b) Figure 7 below shows a block of mass 5.0kg attached to a 2.0kg mass by a light inextensible string which passed over a frictionless pulley. The force of friction between the horizontal table and the block is 4N. The block is released from rest so that both masses move through a distance of 0.5m.

Calculate:i) The work done against friction. (1mk)ii) The acceleration of the system. (3mks)iii) The velocity of the 2kg mass after covering the distance of 0.5m (2mks)c) State the energy changes that occur from the time the motion started until the 2kg mass hits the

ground. (2mks)17. a) State thee pressure law. (1mk)b) Figure 8 below shows a set-up that a student used to investigate the pressure law.

i) State the measurements that should be taken in the experiment. (2mks)ii) Explain how the measurements in (i) above may be used to verify the pressure law. (2mks)iii) Name one limitation of the gas laws. (1mk)iv) Hydrogen gas of volume 2,400 cm3 at 540C and pressure of 2.4M/m2 is compressed until its volume is 300cm3 at a pressure is 6N/cm3. Determine the temperature of the gas after this compression. (2mks)18. a) State the Archimedes’ principle. (1mk)b) The figure 9 below shows a block of mass 50g and density 2000kg/m3 submerged in a certain liquid and suspended from uniform horizontal beam by means of a string. A mass of 40g suspended from the other end of the beam puts the system in equilibrium.

Determine the up thrust acting on the block. (3mks)

c) A simple hydrometer is set-up by filling partly a test-tube of mass 10g, length 12cm and a flat base with lead shots. The test tube has a uniform cross-sectional area of 2.0cm3. 10cm of its length is immersed in water as shown in figure 10 below.

i) Determine the mass of lead shots in the tube. (Density off water = 1g/cm3) (2mks)ii) The mass of the lead shots that should be added for the hydrometer to displace the same amount of a liquid of density 1.25g/cm3 (3mks)19. a) An object is released to fall vertically from a height of 100m. At the same time another object is projected vertically upwards with a velocity of 40m/s. (g= 10m/s2) Calculate:i) The time they take to meet. (2mks)ii) The height above the ground where they meet. (2mks)b) A stone is projected horizontally at a speed of 40m/s from a cliff 60m high. How long will it take to strike the ground? 20. a) A boy ties a stone with a piece of thread. Holding the other end he swirls it in a vertical plane at a constant speed. If the mass of the stone is 200g, and the length of the thread is 40cm and the stone revolves at a rate of 2 rev/s, calculate:i) The angular velocity. (1mk)ii) The tension in the thread when the stone is at the top most position. (2mks)21. a) Define the term velocity ratio as applied to machines. (1mk)b) The table below shows the results obtained in an experiment to determine the performance of a single string pulley system with a velocity ratio of five.

Load (N) 50 100

200 300 400 500 600

Effort (N)

30 45 65 85 105 125 145

i) Plot a graph of load against effort on the graph paper provided. (5mks)ii) Use your graph to determine the mechanical advantage and efficiency corresponding to a load of 450N. (3mks)22. Figure 1 below shows a scale of part of a micrometer screw gauge with a zero error of +0.46mm.

Find the actual reading shown. (2mks)23. State a factor that determine the magnitude of frictional force experienced by body siding on a flat horizontal surface. 24. Figure 2 below shows a beaker 10cm high filled with a liquid of density 1200kg-3. The atmospheric pressure of the surrounding is 1.03 x 105pa.

Determine the pressure at the point marked x at the bottom of the beaker. (3mks)25. State the effect if increasing the temperature in a smoke cell in Brownian motion experiment. (1mk)26. A student observed electric cables near the school compound in the morning and later at mid-day on a sunny day. He found the cables appeared tight in the morning while slack at mid-day. Explain. (1mk)

27. Two students were found to wear different colour of shirts on a weekend. Student A had a white shirt while student B had put on a black shirt. Both students were in a very hot place. State and explain which student is most likely to experience more heat. (2mks)28. Figure 3 below shows a uniform metre bar of weight 2N balanced horizontally with a force F applied Vertically upwards at the 80cm mark while a weight of 0.5N is hung at the 10cm mark.

Determine the value of F, given that the pivot is placed at the 40cm mark. (3mks) 29. Figure 4 below shows a toy bird perching on its beak.

Explain why this is possible. (1mk)

30. Figure 5 below shows three identical springs supporting a mass of 3000g.

Determine the extension of the system if one such spring extends by 1cm when a force of 2N is applied to it. (3mks)40. Figure 6 below shows a Bunsen burner connected to a gas supply.

Explain how it works. (3mks

41. A certain mass of a gas occupies 0.15dm3 at a temperature of 200C and pressure of 98648pa. Calculate its volume if its pressure and temperature changes to 103325pa and 00C respectively. (3mks)13. a) State Newton`s first law of motion. (1mk) b) Figure 8 below shows a block of wood of mass 1980g suspended by a long inextensible rope. An arrow of mass 20g moving horizontally at 160ms-1 is shot at the block. The two move together after collision.

Find:i) The combined velocity immediately after collision. (3mks)ii) The height to which the block and arrow rise after collision, assuming air friction is negligible. (3mks)c) A car of mass 1250kg is moving at 40ms-1 when the brakes are applied so that it comes to rest in 20 seconds. Find the braking force. (3mks)42. a) A water drop is observed to fall from a gutter when it was running. State the energy changes that occur. (2mks) b) A water pump can rise 120kg of water to a height of 10m every minute. i) What is the power output of the pump? ii) If the efficiency of the pump is 80%, what power must be supplied to the pump? (3mks)c) A gear system is made of four gears engaging as shown in figure 9 below.

A engages with B while C engages with D. B and C share the same shaft. A is the driving gear. Determine the velocity ratio of the gear system. (2mks)43. a) State two factors that determine the rate of evaporation of a liquid. (2mks) b) A 400g mass of copper is heated in a Bunsen burner flame until it acquires the temperature of the flame. It is then transferred into an aluminium can of mass 100g containing 200g of water at 200C. The final temperature of water is observed to be 1000C. Neglecting heat losses to the surrounding and taking specific heat capacities of water aluminium and copper as 4200jkg-1k-1, 900 jkg-1k-1 and400jkg-1k-1 respectively, calculate: i) The amount of heat absorbed by the aluminium can. (3mks) ii) The amount of heat absorbed by water. (3mks) iii) The temperature of the Bunsen burner flame. (3mks)44. a) State the law of floatation. (1mk) b) Explain why a hydrometer has: i) A wide bulb. (1mk) ii) A narrow stem. (1mk) c) Figure 10 below shows a block of density 1.27cm3 suspended from a spring balance and completely immersed in oil of density 0.8cm-3. If the block has a height of 20cm and cross-sectional area of 8cm2.

Fig. 10Determine:i) The mass of the block. (2mks) ii) The reading of the spring balance. (4mks) iii) The spring balance reading if the block was ¾ immersed in the oil. (3mks)45. a) Figure 11 below shows two masses 0.2kg and 0.4kg connected by an inextensible string through a hole on a smooth horizontal surface.

The 0.2kg mass rotates in a horizontal circle of radius 4cm. Calculate the angular velocity of thee mass when the system is in equilibrium. Use acceleration due to gravity, g = 10ms-2. (3mks) b) Figure 12 below shows a pipe system WXYZ placed on a flat horizontal surface. Part YZ is semicircular and touched the horizontal surface, with a radius of the semicircular pipe YTZ = 40cm and inernal diameter = 2cm. Water is passed through the pipe system.

i) The velocity of water V, in XY section where radius of the pipe is 1cm. (3mks)ii) The angular velocity as it flows along YTZ. (2mks)iii) The centripetal force required to move a mass of 200g of water along the curved path YTZ. (3mks)46. A bag of sugar is found to have the same weight on planet earth as an identical bag of dry saw dust on planet Jupiter. Explain why the masses of the two bags must be different. (1mk)47. A block of dimension 0.2m by 0.1 by 5cm has a mass of 500g and rests on a flat surface. Determine the least pressure that can be exerted by the block on the surface. (2mks)48. A crystal of potassium permanganate was carefully introduced at the bottom of water column held in a gas jar. After sometimes the whole volume of water was coloured.i) Explain this observation. (1mkii) State the effect of using warm water on the observation above. (1mk)49. A bullet of mass 0.006kg is fired from a gun of mass 0.5kg. If the muzzle velocity of the bullet is 300m/s. calculate the recoil velocity of the gun. (3mks)

50. Some water is poured in two test tubes, one painted black and the other one polished. The apparatus were set up as shown and left in the sun for some time.

i) Record which thermometer records a higher reading after 20 minutes. (1mk) ii) Give a reason for your answer in 4 (i) above. (1mk)51.

A tape attached to a moving trolley is run through a ticker timer as shown in figure3.If the frequency of the ticker timer is 50Hz determine the acceleration of the trolley. (3mks)52. Figure 4 shows water flowing through two sections A and B of a pipe having different cross sectional area.

Indicate and explain the water level in pipe B. (2mks)53. A student used a test tube of diameter 1.2cm and mass 5g to make a hydrometer. To make it float upright he added some lead shots of mass in the diagram. He then placed the hydrometer in a liquid of density 0.8/cm3. It sunk to the depth of 6cm. Calculate the mass of the shots added. (3mks)

54). The figure below shows a flask fitted with a glass tube into a beaker containing water at room temperature.

Explain what is observed when the flask is held with warm hands. (1mk)55. Use the kinetic theory of matter to account for the increase in pressure when a gas has its volume reduced at a constant temperature. (1mk)56. Define centripetal force. (1mk) b) A particle revolves at 4 HZ in a circle of radius 7cm. Calculate its. i) Linear speed (2mks) ii) Angular velocity. (Take = 22/7) (2mks)c) A 150g mass tied to a string is being whirled in a vertical circle of radius 30cm with uniform speed. At the lowest position, the tension in the string is 9.5N. Calculate, i) The speed of the mass. (3mks) ii) The tension in the string when the mass ia at the uppermost position of the circular path. (Take g = 10m/s2). 57. a) State what is meant by the term specific latent heat of vaporization. (1mk) b) In an experiment to determine the specific latent heat of vaporization of water steam at 1000C was passed into water contained in a well lagged calorimeter, the following measurements were made:Mass of calorimeter 60g Initial mass of water 80g Final mass of calorimeter + condensed steam 143g Initial temperature 170C Final temperature 320C Specific heat capacity of copper 390jKgK. i) Determine the mass of condensed steam. (1mk) ii) Determine the heat gained by calorimeter and water. (3mks) iii) Determine the latent heat of vaporization off steam. (3mks)58.a) i) Define pressure. (1mk) ii) A student off a certain school connected a U-tube to a gas supply in the laboratory and obtained the readings as shown below.

Given that the density of mercury is 13600kg/m3 and the atmospheric pressure is 760mm Hg. Determine the gas pressure in mmHg. (3mks) iii) State three properties of a suitable hydraulic fluid. (3mks)b) Explain why racing cars have wide tyres.

(1mk)c) The hydraulic lift below was used to support a uniform metal rod horizontally in a construction site. The rod is 50m long and weighs 500N.

If support T is 10m from B and cross-sectional area of effort arm is 2.0m2 and the load arm 4.0m2.Determine;

i) Force exerted on the rod by the load arm. (3mks) ii) Distance of the load arm from point A. (2mks)59. a) Define the term work and state its S.I unit. (2mks) b) The figure shows a force-distance graph for a car being towed on a horizontal ground.

i) Calculate the total work done. (4mks) ii) If the velocity just before reaching C is 0.6m/s. Calculate the power developed by the agent providing the force at this point. (2mks)c) An electric pump can raise water from low level reservoir to the high level reservoir at the rate of 3 x 105kg/h. The vertical height of the water is raise is 360m. If the rate of the energy loss inform of heat is 200kw determine the efficiency of the pump. (4mks)60. a) Distinguish between elastic and perfectly inelastic collusions. (1mk)1. a) State Lenz`s law of electromagnetic induction. (1mk) b) Two identical copper coil P and Q are placed close to each other as shown in figure 10.. Coil P is connected to D.C power supply and coil Q is connected to a galvanometer, g.

State and explain what would be observed on the galvanometer immediately the switch is close (2mks) c) Figure 11 shows a diagram of a simple electric generator.

I) Name the parts labeled A and B. ii) On the axis provided in the diagram below sketch the output as seen on the screen of the cathode ray Oscilloscope (COR) when the a mature is rotated starting at the position shown in figure 11.

iii) State two factors that would affect the value of the voltage output. (2mks) d) A transformer has 400 turns in the primary coil and 20 turns in the secondary coil. If the primary voltage and the primary current are 120v and 0.5A respectively determine the value of the secondary current. State any assumption made. 17. a) i) The following reaction is part of a radioactive series.

Identify the radiation r and determine the values of b and c. (3mks)ii) A radioactive sample of half- life 130 days initially has 1.0 x 1020 radioactive atoms.Determine the number of radioactive atoms that have decayed after 390 days. (3mks) ii) Explain the following in an x- ray tube. a) The tube is evacuated. (1mk) b) The anode is made of thick copper metal. (1mk) c) The shield is made up of lead. (1mk)18. a) You are provided with the following apparatus to determine the focal length of a lens.

- A biconvex lens and lens holder.- A lit candle- A white screen and A metre rule

i) Draw a diagram to show how you would arrange the above apparatus to determine the focal length of the lens. ii) Describe the procedure you would follow.

(1mk) iii) State two measurements that you would take. (2mks) iv) Explain how the measurements in (iii) would be used to determine the focal length. (2mks)a) An object is placed 30 cm in front of a concave lens of focal length 20cm. Determine the magnification of the image produced.

(4mksb) Figure 13 shows a progressive wave crossing from shallow to deep region

Show on the diagram how the waves proceed in the deep region. (1mk) c) Explain why ratio wave signals are easier to receive than TV waves signals in a place surrounded by hills (2mks)A ray of light strikes the mirror horizontally as shown in the figure. Trace the path of the reflected ray showing the angles of incidence (1) and reflection (2mks)2. A wire is wound on an iron rod and a current passed through thee wire as shown in figure 2 below.

The end B of the rod is brought close to the North Pole of a suspended magnet (fig 3) State and explain the observations made. (2mks)3. State two factors that affect the speed of sound in air. (2mks)4. The chart below shows an arrangement of different parts of the electromagnetic spectrum.

RadioWaves

A VisibleLight

B X-rays Gammarays

Name the radiation represented by B. (1mk)11. Give one difference between x- ray and cathode rays. (1mk) 83 Bi has a half-life of 20 minutes what percentage of 83 Bi remains after one hour. (3mks)13. A form four student set up a circuit as shown in figure (9) below

State and explain the observations made when the switch is closed. (2mks)14. a) I) State the law of reflection. (2mks) ii) One of the conditions for total internal reflection to occur is that the angle of incidence must be greater than the critical angle of the medium. State the other condition. (1mk)15. a) A charged body is brought near a negatively charged electroscope. It is observed that the leaf of the electroscope collapse. State the charge on the body. (1mk) ii) Explain the above observation. (1mk)b) Figure 11 shows a pair of parallel plates of a capacitor placed close one another.c) Four capacitors are connected in a circuit as shown in figure 12 below.

Determine:i) The total capacitance in the circuit. (3mks)ii) The charge on capacitor D. (3mks)iii) The potential differences across capacitor B. (3mks)16. a) Define current. (1mk) b) Figure 13 below shows an electric circuit with two bulbs X and Y which are identical.

Explain what happens to the bulbs when: i) S1 only is closed. (2mks)

ii) S1 and S2 are closed. (2mks)c) Figure 14 below shows an electric circuit.

Use the circuit to calculate the current supplied by the battery. (3mks)17. a) i) Explain why power is transmitted at high voltage along the transmission line. (1mk) ii) A drier is rated 2.5kw, 240v. Explain why it is not advisable to use 10A fuse for the drier. (3mks)b) i) What do you understand by the term induction? (1mk) ii) Figure 15 below shows an induction coil used to produce sparks.

Name the parts labeled A, B and C. (3mks)c) A transformer is used on a 240v a.c supply to deliver energy taken from the supply to an electric bell rated 120w, 12v. If 20% of the energy is dissipated in the transformer, calculate the supply current (3mks)18. a) A student set up an experiment in the laboratory as shown in figure 16 below

He directed a u.v light on the cathode of the photocell and observed that the galvanometer deflects. i) Explain this observation. (1mk)ii) State one condition that must be met for the galvanometer to deflect. (1mk)b) A surface whose work function W =6.4 x 10-19j is illuminated with light of frequency 3.0 x 1015HZ. Find the maximum kinetic energy of the emitted photoelectrons. (Taken h = 6.663 x 1034JS) (3mks)c) i) State one application of a cathode ray oscilloscope. (1mk) ii) Figure 17 below represents a display of an a.c signal on the C.R. O screen

Determine the frequency of the signal given that the time base is 200ms per division. (3mks)6. An electric bulb rated 12V, 26W allows current to pass through for 1 hour. Determine the electrical energy dissipated by the bulb. (1mk)11. An X-ray tube is operating with anode potential of 20kv and a current of 40mA. Determine the number of elections hitting the target per second. (The charge of an electron is 1.6 x 10-19C). (2mks16 a) i) It is not advisable to fix a fuse on the neutral wire in domestic wiring. Explain. (2mks) ii) Explain why there are fuses of different ratings in the distribution box. (1mk)b) A power company supplies electrical energy and charges the consumption to ordinary consumers as follows: Ksh 75 as monthly fixed charge Ksh. 10 per unit for the first 50 units consumed Ksh per unit for the next 51-3000 units( 1 unit = 1KWh) A consumer uses 1.98 x 105 kilojoules of electrical energy in a given month.Determine: i) The number of units consumed in KWh. (2mks) ii) The cost of electrical energy consumed. (2mks)17. a) Distinguish between photoelectric effect and thermionic emission. (1mk) ii) A radioactive material was picked from a cave. It`s average count rate was found to be 97 counts per second. After a time of 210 seconds, the count rate was registered as 34 counts per second. The average background count rate remained 25 counts per second. Determine it`s half-life. (2mks) vii) Explain why the tube of a cathode ray oscilloscope (C.R.O) is made of thick glass walls. (½mk)21. a) State the condition necessary for Ohm`s law to be obeyed. (1mk)23. a) Distinguish between a p-type and n-type extrinsic semi-conductors. (2mks) b) Draw a diagram to illustrate forward bias of a p-n junction. (1mk)

c) Fig 20 below shows a bridge rectifier.A capacitor has been connected across the resistor as shown in the figure. i) Sketch on the axes below the wave form when a C. R. O is connected across the resistor. (1mk) ii) Sketch on the same axes above the wave form when a C.R.O is connected across the resistor R and capacitor C removed. (1mk)