50851450-nota-sains-t5

TOPIC: MICROORGANISM AND THEIR EFFECTS ON LIVING THINGS

Learning Outcomes: At the end of this season, the pupil will be able to:i. list the characteristics of various types of microorganismsii. classify microorganisms into bacteria, fungi, protozoa, viruses and algaeiii. describe the characteristics of each group of microorganismsiv. identify factors that affect the growth of microorganism.v. state example of uses of microorganismvi. state the harmful effects of microorganisms on human healthvii. relate each group of microorganisms to the diseases caused by itx. state various ways microorganism can cause infectionix. list ways to prevent infection

1

2 Characteristics each type of microorganisms

Characteristics Viruses Bacteria Protozoa Algae Fungi

Shape Round,Spherical,spindle

Round,Filamentous,colonial

Size 0.5 µm or smallest

0.2 -10 µm 5 - 250µm 10 -100 µm

Nutrition AutotrophicSaprophyte / Parasite

Autotrophic/Parasitic,

Saprophyte / Parasite

Habitat Living cells Air,water,soilFood,livingorganism,decaying matter

Fresh water,sea water,damp soil, barks of trees

Decaying organisms matter,outside/inside living organisms

Method of rerroduction

Binary fission,conjugation

Binary fission,conjugation

Binary fission,spore formation,conjugation

STF Science Remedial Module ( SPM )

BacteriaX……………

FungiY……………….

.

Viruses

68

Types of microorganisms

3 Factors that affect the growth of microorganisms

1. ………………………2 pH value

3 ....................................4 nutrients5 ……………………….

4 Example uses of microorganism

a. Yeast – making bread, soya sauce and alcoholic drinksb. Bacteria – making vaccine and useful to digest food in human intestinec. Fungi – use to produce antibiotics such as penicillind Viruses – making vaccine and used in biological control

5 Harmful effects of microorganism

Pathogens(Microorganisms that cause

disease)

Diseases

Bacteria

Viruses

Protozoa

Fungi

6


69

How diseases spread ?

Through Air

7


70

Infection caused by pathogens

Sterilisation

Can be prevented by

Learning Outcomes: At the end of this season, the pupil will be able to:i. explain how nutrients, humidity, light, temperature and pH affect the growth of microorganisms.


Factors that affect the growth of microorganism

Temperature200C - 450C – grows rapidlyTemperature too low – become passive or do not growTemperature too high

- die /kill because the enzymes produced destroyed

pH value

pH 7(neutral) – grow rapidly

pH too high or too low - stop growing /dieSlightly/ acidic/alkaline – some microbe grows

Light

Microorganisms which contain chlorophyll require light for making their own food through photosynthesis

Microorganisms that do not contain chlorophyll grow and reproduce faster without light

HumiditySome live in waterMost live in damp or wet placeRelative humidity between 25% and 40 %In dry or less humid place – cells of microorganisms will lose water & become inactive

71

Nutrients

Need nutrients to provide energy for growth & reproduce

Parasitic (absorb nutrients from their host cells

Saprophytic (absorb nutrients from dead/decaying organisms

Make their own food through photosynthesis if microorganism have chlorophyll

Learning Outcomes: At the end of this season, the pupil will be able to:i. state the harmful effects of microorganisms on human beingsii. relate each group of microorganisms to the disease caused by it.iii. describe the various ways microorganisms can cause infectioniv. list ways to prevent infections.v. relate the control of vectors to their habits and life cycles.

1. Diseases caused by pathogen (microorganisms that cause diseases) and the ways of spreading.

Disease Pathogen Ways to spreading

Cholera

Diphtheria Bacteria Air

Gonorrhoea Contact

Tuberculosis Bacteria

Syphilis

Dysentery Protozoa Contaminated & contaminated food

Malaria

Influenza

Dengue fever VirusVectors

Hepatitis B

Poliomyelitis

Chickenpox VirusAir & contact

AIDS

Ringworm Fungi


72

2.


73

How diseases spread ?

Through air Pathogens are

carried in the air When a person

breathes in the air, pathogens enter

the body When a person

cough, talk, breathes or sneeze, pathogens release from the person body in droplets of water

Disease :TB, Influenza

Through water Water contains pathogens

flows & carried from one place to another

When a person drinks the water, the pathogen enter the body of the person

Disease : Cholera

Through contaminated food Improper handling of

food can cause contamination. Pathogens may come

from surroundings, faeces and vectors.

Disease: Hepatitis, cholera

Through vectors : Example Mosquito - When a person is bitten by a mosquito, the pathogens in the saliva of the mosquito enter the bloodstream of the person. This may cause the person to fall sick. Housefly- When a housefly lands on food, pathogens are

transferred from its legs or body to the food. This may cause the person that eat the food to fall sick.

Disease : Malaria, Dengue fever

Through contact Direct contact (sexual

activities) with infected person may cause transfer of

the microorganism. Indirect contact (sharing

personal items) may also spread the disease.

Disease :Ringworm

3


74

Infection caused by pathogens

Sterilisation Process which pathogens are

destroyed/removed from the object /environment

Method :1.Heat2.Radiation3.Chemicals

Can be prevented by

Vector control

Immunity

Body ability to destroy pathogens before they can cause disease 2 type of immunity

1. Active immunity a. Natural active immunity- acquired when a person recovers from thedisease caused by pathogensb. Artificial active immunity- acquired not by being infected with the disease but by vaccinationagainst the disease- Vaccination is the process in which harmless antigens or substancesreleased from pathogens are introduced into a person’s body to stimulatethe body to produce immunity.- Vaccine consists of dead antigens, weakened pathogens or toxin ofpathogens which have been harmless. The vaccine stimulate the immunesystem to produce antibodies which can fight the disease

2. Passive immunity a. Natural passive immunity- A baby acquired natural passive immunity before birth when antibodiesfrom the mother’s are passed on through placenta-A baby acquired natural passive immunity after birth by feeding on themother’s milk which contains antibodies.b. Artificial passive immunity- acquired by injecting the antibodies from other organism such asantiserum

4 Method of controlling used foer each stage of the life cycle of the mosquito.4. Method of controlling used for each stage of the life cycle of the housefly.


75

Spray a layer of oil on the water surface to prevent pupa/larvae from breathing.

Rear fish (eg guppies) to eat the pupa/larvae

Use insecticide aerosol spray on adult mosquitoes. Put up mosquito nets/repellents to prevent from being bitten by adult mosquitoes

WaterWater

Pupa

larva

Egg

Adult

Adult Use insecticide aerosol spray on adult fly.

At the egg, pupa and larva stagesdestroy the breeding ground of houseflies by disposal waste food, decaying matter & rubbish// burying //dispose//wrapping garbage properly

.

Larva

EggPupa

Destroy breeding grounds of mosquitoes by cleaning /draining swamps,ponds & containers filled with water

TOPIC: NUTRITION

Learning Outcomes :At the end of this session, the pupil will be able to :

i. state what macronutrients areii. list macronutrientiii. state what micronutrients areiv. list micronutrientv. state the effects of nitrogen, phosphorus and potassium deficiency on plant growthvi. state the major functions of nitrogen, phosphorus and potassium in plant growthvii. describe the nitrogen cycleviii. explain the process involved in the nitrogen cycle

Note:

1. Macronutrien – nutrient which are needed in large quantities . - example : carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium calcium, magnesium and sulphur.

2. Micronutrien - nutrient which are needed in very small quantities. - example : boron, molybdenum, zinc, manganese, copper and iron.

3. The effect of deficiency of : Nitrogen - retarded growth, leaves turn yellow Phosphorus - retarded growth, upper leave turn purple, poor root growth Potassium - retarded growth, weak stems, dead spots of leaves

4. Major function of : Nitrogen - to synthesise protein/chlorophyll/ Phosphorus - to synthesise chromosomes/function as co enzyme Potassium - to synthesise protein/maintain turgidity

5. Nitrogen Cycle : Process Added Nitrate to soil. - Lightning, Volcanic eruption,nitrification,

Nitrogen-fixing bacteria. Process Removed Nitrat from soil - Denitrifying bacteria, leaching.

Decay bacteria lightning volcanic eruption nitrogen-fixing bacteria

ammonium compound nitrates denitrifying bacteria leaching


76

nitrifying bacteria nitrification leguminous

(a) Nitrogen cannot be used directly by plants. Nitrogen has to be changed into ___________________________________ before it can be used by plants.

(b) State two processes which added nitrates to the soil at high temperature. i. _____________________________ ii. ______________________________

(c) Nitrogen fixation involves ___________________________ bacteria found in the soil and the roots of _______________________________ plants.

(d) When plants and animal died, break down dead remains to

form ____________________________________.

(e) The ammonium compounds are converted into nitrites and then nitrates by _____

____________________. These process are called _______________________

(f) State two processes which remove nitrates from the soil. i. ______________________________ ii. _______________________________

TOPIC: PRESERVATION AND CONSERVATION OF THE ENVIRONMENT

Learning Outcomes:At the end of this session, the pupil will be able to :

i. describe global warmingii. relate greenhouse effect to global warming.iii. state what ozone layer is.iv. explain the importance of ozone layer.v. state the chemicals that damage the ozone layer.vi. list the sources of chemicals that can damage the ozone layer.vii. explain how damaging the ozone layer affects living things.

1 Global warming

Relates to the increase in the average temperature of the Earth’s atmosphere. This causes :

a. the glaciers and ice caps in the Artic & Antartic to meltb. the sea level will rise causing coastal floodingc. the changes of normal weather patternsd. causes floods, drought and more devastating hurricanes & typhoons

The greenhouse effect is the problem caused by heat being trapped on Earth by the greenhouse gases such as carbon dioxide, methane, nitrogen oxide and chlorofluorocarbons(CFCs) in the atmosphere


77

2 Ozone Depletion

Ozone layer consists of a layer of gas called ozone. The thinning of ozone layer is due to ozone-depleting substances such as CFCs,

hydrochlorofluorocarbons (HCFCs) & halons that are released into to the atmosphere

CFCs made up of chlorine, carbon and fluorine.


78

CFCs used in industries as refrigerators, propellants and cleaning solvents. CFCs can be found in aerosol sprays & the cooling system. Chlorine atom of the CFCs reacts chemically with the ozone molecule resulting the

reduction of ozone molecules HCFCs consists of carbon, hydrogen, chlorine and fluorine. HCFCs are used to replace CFCs, HCFCs contains less percentage of chlorine compare

with CFCs. Halons are compound made up of bromine, fluorine & carbon atoms Halons are used in fire extinguishing agents. The bromine in halons can destroy ozone Effects of ozone depletion : causes an increase in the UV rays reaching the Earth’s. This increase in the harmful UV rays will cause skin cancer & cataract of the eye Excessive exposure to harmful UV rays will cause :

1 drastic changes in our climate,2 lower the immunity of organisms3 cause mutation4 reduce the yield of crops & kill phytoplankton that will affected food web & cause the

reduction of the number of producers namely plants & phytoplankton. This will cause the energy supplied to consumer in the food web to decrease affecting the balance of nature.

TOPIC: CARBON COMPOUND

Learning Outcomes:At the end of this session, the pupil will be able to :

i. state what carbon compounds areii. state what organic compounds areiii. give examples of organic compoundsiv. state what in organic compounds arev. give examples of inorganic compoundsvi. classify substances into organic and inorganic compoundsvii. state what hydrocarbons areviii. list sources of hydrocarbons

Importance Points

Carbon CompoundsDefinition: Formed from the chemical combination of carbon with one or more of other elements

Types

Organic Compounds Differences Inorganic compounds

Living organism ( eg. Plants and animals)

Sources Mineral substances(Do not originate from living things)

Their molecules are made up of more carbon atoms

Number of carbon atoms per molecule

Their molecules are made up of fewer carbons atoms

Carbon, oxygen, hydrogen,nitrogen

Element present Carbon, oxygen, metallic element

Soluble in organic solvent such as petrol,alcohol and ether

Solubility Soluble in inorganic solvents such as water, acids and alkali


79

Combine with oxygen A lot of heat is released

Changes when heating Oxides of carbon unchanged

Carbonates of metals usually decompose

Yes Flammable No

Low Melting points High

Originate from animals:Animal proteins, silk, cheese, milk, butter and leatherOriginate from plants:Plants proteins, rice, wood, cotton and latex

Examples Carbon oxides ( e.g: carbon monoxide & carbon dioxide)Cynide( e.g: sodium cyanide &magnesium ctanide )Carbonate compounds ( e.g: calcium carbonate or limestones)

HydrocarbonDefinition: Carbon compound which contains only carbon and hydrogen

elements in specific ratio.

Learning Outcomes:


80

Unsaturated(Contains double bonds between carbon atoms)

Formed from plants and animals that died millions of years agoPetroleum is trapped between the layers of impervious rocks while natural gas is always found on top of petroleum

Saturated(Contains single bond between carbon atoms)

SOURCES

Coal Natural gas Petroleum

Formed from the remains of lush vegetation that grew in warm shallow coastal swampsThe dead plants slowly become rockConsists of complex organic compounds and mixture of chemical substances

At the end of this session, the pupil will be able to:i the process of producing alcoholii. state the general characteristics of alcoholsiii. list uses of alcoholiv. explain with examples the effects of alcohol on health

IMPORTANT POINTS:12 .2 Alcohol

Alcohol A group of organic compound made up of the elements carbon, hydrogen and oxygen Contain the –OH functional group which determines their reactions The names of all alcohol end with ‘-ol’ Examples: methanol, ethanol, propanol

Physical properties Uses

Chemical properties

Effects of alcohol on human being


81

HEALTH

Slow down the time of reaction Nerves system become less sensitive to

stimulus Act as depressant if taken in excessive

alcoholic drinks Losing self-control Causing vomiting Liver damage Brain damage Hepatitis High blood pressure

SOCIAL PROBLEM

Road accident Family problem Robbery as a drinker tend to have aggressive personality and often quarrel Improper judgment and thinking

Liquid in room temperatureColourlessSweet smellEvaporates easilyDissolves in water at any ratioDissolves in organic solvent

Used as fuelUsed as solventUsed in food and drink productionUsed in cosmetic manufactureUsed in medical field

CombustionBurn easily in the airBurn with blue flame, little or no sootProduce carbon dioxide gas and water

Alcohol + oxygen carbon dioxide + water

Alcohol

Blue flame

Esterification

EsterWater

EthanoicAcid +Ethanol

Concentrated sulphuric acid

ConcentratedSulphuric acid

Alcohol + organic ester + water acid

Sweet smellInsoluble in water

Preparation of ethanol

1. By fermentation process

Purification of ethanol by distillation process

Learning Outcomes:At the end of this session, the pupil will be able to:


82

Glucose + yeast ethanol + carbon dioxidezymase

GlucoseSolution + yeast cells

Lime Water

Observation:Turns chalkyInference:Carbon dioxide gas is released.

Delivery tubeYeast-function to

produce zymase Zymase an enzyme

act as catalyst

i. describe the process of making soapii. state that soap is a salt produced by the reaction between sodium hydroxide

and fatty acidsiii. state the characteristics of the components of a soap moleculeiv. explain the cleansing action of soap molecules

IMPORTANT POINTS

1. The process of making soap ( Saponification )

Word Equation for Saponification Process :


83

Filtrate

Residue(soap)

Stirred with aglass rod

Palm oil + sodium hydroxide solution

Sodium chloride

1.Palm oil (vegetable oil) is slowly boiled with sodium hydroxide solution ( alkaline solution) and the mixture is stirred with a glass rod

2.Common salt ( sodium chloride) and water are added to the mixture

3.Sodium chloride can reduce the solubility of soap that formed

4.The mixture is boiled and then is allowed to cool

Mixture is filtered with filter paper

Residue of soap

Stirred the mixture with a glass rod

1.The mixture is than poured through a filter funnel with filter paper to separate the precipitate 2.The residue on the filter paper is rinsed with some water and left to dry

3.The plenty of bubbles or foam are formed, when some residue is stirred with water

4.The residue is smooth when touch with a wet finger

Residue( Soap)

Filtrate(glycerol + water)

Function:To make the soap float to the surface

Palm oil + Sodium hydroxide Sodium salts of fatty acid +Glycerol +water

MOLECULE STRUCTURE OF SOAP

The Cleansing Action of Soap Molecules


84

Natural ester(Glycerol-fatty acid)

Alkaline Soap

Ionic Head(Hydrophilic)

Hydrocarbon Tail(Hydrophobic)

1.The head part is ionic, it is the ‘water-loving’ end.2.It ionizes in water,giving it a slight negative charge3.Soluble in water

1.The long hydrocarbon chain is bonded by covalent bond.

2.It is the water ,giving it a slight negative charge3.Soluble in water

Soap molecule is shaped like a tadpole, with a ‘ head’ consisting an electrically charged ion and a ‘long tail’ consisting of a long hydrocarbon chainThe soap molecules decomposes to form potassium or sodium ions which charged positively and soap ions which charged negatively.

TOPIC: MOTION


85

Cloth stains with grease

Hydrophobic end (head) of soap molecules embedded in grease

Water

Hydrophilic end (head) of soap molecules sticking out of grease

Soapmolecules

Grease

Soap molecules reduce surface tension and enable it to penetrate and then wet the cloth

Water is shaken

1.Foam of soap help to float the emulsion

2.When dirty water and soap foam are thrown as well. The cloths are cleaned

1. Attraction of the head end of soap molecule to water and the washing motion of the cloth ( motion when the cloth is agitated ) pull off the soap and grease2.Grease dirts are removed from cloth surface as emulsion (oil droplets)

Step 1 Step 2

Step 3 Step 4

Learning Outcomes: At the end of this season, the pupil will be able to:i. state what inertia is ii. give examples of everyday occurrences that involve inertiaiii. explain with examples the relationship between mass and inertia

IMPORTANT FACTS

Learning Outcomes: At the end of this season, the pupil will be able to:


86

Inertia Definition: The tendency of an object to maintain its original position

whether stationary or in motion 2 types of inertia :

Stationary inertia Motion inertia

Stationary inertia - tendency of an object to resist any changes to its stationary position

Motion inertia-tendency of an object to move against the force acted on it The greater the mass, the greater the inertia. Example:

When the cardboard is pulled quickly, the coin drops into the glass Because the stationary inertia of the coin maintain its original position

When a moving car suddenly stops, the passengers will thrown forward. This is because the motion inertia tries to maintain the movement of the

passengers forward

A big stone is hard to move because its stationary inertia is big

A motorboat can easily change its direction of its motion compare to a big ship because the motorboat’s inertia is smaller.

Safety measures in vehicles that concern to inertia1. By fastening seat belts, the driver and passenger can be stopped from moving forward or being thrown out of the car because of inertia.

2. When accidents occur, the air bags in some vehicles will be inflated with gas and expand to prevent the driver from being thrown forward due to his motion

of inertia

coin Cardboard

glass

i. understanding the concept of the Archimedes’s Principle Archimedes’s Principle = An object is immersed in a liquid , the up trust on the ( A P ) object is equal in size to weight of the fluid displaced by object .

Concept AP : = +

: Weight of displaced water = the up thrust force

1. Refer to the diagram AP above , complete the incomplete tables below .

WEIGHT ( Newton )Block in Air Empty

BeakerBeaker +

Water Block in Water

Water displaced


W Newton ( N )

B0 ( N )

W = Weight of block in air B = Weight of empty beaker

Scale measurement

W 1 Newton ( N )

B 1 ( N )

W 1 = apparent weight of block in waterB 1 = Weight of beaker + displaced water

(B 2 )Weight Displaced Water = B1 – B0

87

W W1 ( B1 – B0 )

Diagram A P

DisplacedW

( N )B0

( N )B1

( N )W1( N )

B2 = B1 – B0( N )

a)10 1 6.5 4.5 5.5

b) 2 10

c) 4 13

d) 3 14.5

Check out : W = W1 + B2

1 HOURLearning Outcomes: At the end of this season, the pupil will be able to:i. define speed, velocity and accelerationii. state the unit for speed, velocity and accelerationiii. solve problems involving velocity and acceleration

IMPORTANT FACTS:

Definition:

Speed is the rate of change of distance Velocity is the rate of change of distance travelled in a specific direction Acceleration is the rate of change of velocity

Units:

Speed / Velocity - ms-1

Acceleration - ms-2

Formula :

Speed / Velocity = Distance (m) Time taken (s)

V = s t

Acceleration = Final velocity - Initial velocity (ms -1 ) Time Taken (s)

a = v – u t

Examples of problem solving:Eg. 1 A car starting from rest attains a velocity of 20 ms-1 in a time of 5.0s. What is its

acceleration?

Step:


88

A Underline the important facts on the question

u=o v= 20 t = 5A car starting from rest attains a velocity of 20 ms -1 in a time of 5.0s. What is itsacceleration? a ?

B Use the formula and insert the data

a = v – u t

= (20-0) ms -1 5 a

= 20

5 = 4 ms-2

s= 20Eg.2 A football player kicks a ball 20 meters from the goal line. The ball take

4 seconds to cross the goal line. What is the speed of the ball? t = 4 ?

Speed = Distance Time taken = 20 m 4 s = 5 ms-1

u = 30 v= 0Eg.3 A car is moving at a velocity of 30 ms -1 . The driver brakes and the car stops within 6 seconds. What is the acceleration of the car?

t= 6 a = ?

a = v – u t

a = 0-30 ms-1

6 s

a = -30 = -5 ms-2

TOPIC: FOOD TECHNOLOGY AND PRODUCTION1 HOUR

Learning Outcomes :


89

i. give examples of processed food.ii. to know the purpose of processing food.iii. to understand the functions of the chemicals used in food processing.iv. to understand the effects of the use of chemicals in excessive amounts in food processing.

Question 1 :

Choose the words below and match to the appropriate picture.


Canned food

Vacuum packing

Dehydration UHT milk

Instant coffee powder Pasteurised fresh milk

90

Question 2 :


91

Choose the correct words and write in the columns provided below.

Colouring Bleach Sweetener Anti-oxidants Flavouring

Harmful effects Food additive

CancerHivesRashes

1.

CancerInfertilityFood poisoningAffects sightMentally retarded children

2.

Stunt body growthDamage the liver and kidneysRashesHives

3.

CancerFood poisoning

4.

CancerBrain damage for childrenTightness in the chess (asthma)

5.

Question 3 : Tick ( / ) the true statements and ( X ) the wrong ones.

1. Processed food is food that has been treated with chemicals or undergone certain processes. ( )

2. Planting alternate crops can prevent soil erosion effectively. ( )

3. Food that is genetically modified is guaranteed safe to be eaten. ( )

4. We will be paid back if we buy expired food. ( )

5. All the food processing methods destroy the nutrients in food. ( )


92

TOPIC: SYNTHETIC MATERIALS IN INDUSTRY

Learning Outcomes:At the end of this session , the pupil will be able to ;i. State the uses of synthetic polymersii. Relate the general characteristics of synthetic rubber to its usesiii. Give examples of goods made from a combination of natural and synthetic rubberiv List the characteristics of thermoplastic materialv List the characteristics of thermosetting plastic materialvi Classify various plastics goods into thermoplastic and thermosets

1. Complete the table with the answer given below

Polyethene Polyvinyl chloride (PVC) Polyesters ( Terylene) Nylon

Type of polymer Its uses

………………………. Stockings, clothing, ropes, toothbrush bristles

……………………… Furniture, waterproof and insulating materials

……………………… Cotton and wool substitute in clothing’s, tire cord and safety belt

………………………. Cling film, plastic bags, sheets and bottles

2. Diagram 1 shows the process involved in the formation of polythene

Monomer Polymer DIAGRAM 1

1. Name the process taking place ………………………………………. 2. Name the monomer used ………………………………………….3. State one characteristic of polythene ………………………………… …………………………………………….


93

3. Complete the table with the answer given below

Polyethene Teflon (PTFE) Polystyrene Nylon Terylene

Melamine Perspex Bakelite Polypropene Epoxy polymer

4. Diagram 2, shows various product found in most households.

DIAGRAM 2

(i). State four characteristics of thermosetting plastics, based on the product above.

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


Plastics

Thermoplastics Thermosets

94

1.2.3.4.5.6.

1.2.3.4.

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

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

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

(ii).

Proper management of the disposal of plastic materials is important to reduce pollution of the environment

State four ways to manage disposal of plastic materials

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

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

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

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

TOPIC: ELECTRONIC

Learning OutcomesAt the end of this session , the pupil will be able to ;

i. describe the characteristics of waves.ii. identify different types of waves that form the electromagnetic spectrum.

Exercises:

1. Diagram below shows a transverse wave.

A and B are two of the waves characteristics. What are they?

A: ___________________________


95

B: ___________________________

2. Fill in the table below with the given characteristics of waves.

CHARACTERISTICS OF WAVESExplanation Characteristics

The number of complete waves generated per second.The distance moved by the wave in one second.The distance between two successive crests or two successive troughs on the transverse wave.The maximum displacement of a wave particle from its equilibrium position or resting position.

3. Figure A and B show two different transverse waves. Compare the frequency and wavelength of the two waves.

Figure A Figure B

Frequency: High Frequency: _________

Wavelength: __________ Wavelength: ________


96

Amplitude, A Wavelength,λ Frequency, f

Wave velocity, v

4. Figure below shows the electromagnetic spectrum.

Place the given types of waves to the right boxes in the diagram.

5. Table below shows the type of radio waves, their wavelength ranges, frequency ranges and applications. Complete the table.

TYPE OF RADIO WAVE

WAVELENGTH RANGE

FREQUENCY RANGE

APPLICATIONS

Long waves, LW or Low Frequency, LF

1000m – 10000mRadio

communicationsMedium waves, MW

or Medium frequency, MF

300kHz – 3MHzRadio

communications, AM radio broadcasting

Short Waves, SW or High Frequency, HF

10m – 100m 3MHz – 30MHz

1m – 10m 30MHz – 300MHz

Radio communications, FM

Radio and TV broadcasting.

Ultra High Frequency, UHF

300MHz – 3 GHzRadio

communications, TV broadcasting

Microwave 1mm – 10cm

TV broadcasting, mobile phone,

satellite communications


97

Radio waves Microwaves Infra-red

Ultraviolet Gamma rays

6. Diagrams below show three different ways by which radio waves are transmitted. Match the explanation given below with the diagrams.

EXPLANATION A EXPLANATION B EXPLANATION C Long waves Frequency up to 2MHz. Travel along the Earth

surface following its curvature.

Medium waves Frequency between 3 and

30MHz. Reflected by ionosphere to

the ground.

Short waves and microwaves

Frequency above 30MHz. Travel in straight lines and

can pass through the ionosphere and out to space.

SKY WAVES SPACE WAVES GROUND WAVES

Learning Outcomes:At the end of this session , the pupil will be able to ;

i. Identify the electronic components used in the radio and their symbols.ii. Describe the radio transmission system.iii. Describe the radio receiver system.

1. Table 1 below shows electronic components, their symbols and functions in a radio. Fill in the blanks by drawing the symbol in the table.

ELECTRONIC COMPONENTS

SYMBOL FUNCTION

Aerial

To pick up all available radio waves with different frequencies within the range.

Inductor

Works with a variable capacitor to form a tuning circuit.

Variable capacitor

Works with an inductor to form a tuning circuit. Its capacitance can be adjusted to change the frequency of the radio in order to match the frequency of the radio waves transmitted from the station.

DiodeTo act as a rectifier separating the a.f. signals from the amplified modulated


98

r.f signal through demodulation.

Capacitor

To channel the flow of r.f. carrier waves into the Earth.

Transistor

To amplify the a.f. signals before sending them to the loudspeaker or earphone.

Resistor

Works with a transistor to amplify the a.f. signals

Transformer

To change the voltage of an alternating current.

TABLES 1

2. Diagram 1 shows a block diagram for a radio transmission system. Label components A, B, C, D, E and F.

DIAGRAM 1

A: _________________________________________

B: _________________________________________


99

C: _________________________________________

D: _________________________________________

E: _________________________________________

F: _________________________________________

3. What is the function of component A, B, C and D in the diagram 1?

A: The function of ________________ is to __________________________

B: The function of ________________ is to __________________________

C: The function of ________________ is to __________________________

D: The function of ________________ is to __________________________

4. Diagram 2 shows a block diagram for a radio receiver system. Complete the diagram by labeling components A, B, C, D, and E.

DIAGRAM 2

A: _________________________________________

B: _________________________________________

C: _________________________________________

D: _________________________________________

E: _________________________________________


100

5. What is the function of component A, B, C, D and E in the diagram 2?

A: The function of ________________ is to __________________________

B: The function of ________________ is to __________________________

C: The function of ________________ is to __________________________

D: The function of ________________ is to __________________________

E: The function of _____________


101

50851450-nota-sains-t5

Documents

harmful uv

insecticide

radio transmission

radio receiver

learning outcomes

natural gas

organic compounds

sodium chloride