1.0 MAGNETISM

1.1 Introduction:

• Magnetism is the force that a magnetic object exerts, through its magnetic field, on another

object. The two objects do not have to physically touch each other for the force to be exerted.

Object 2 feels the magnetic force from Object 1 because of Object 1’s surrounding magnetic

field.

• Humans have known about magnetism for many thousands of years. For example, lodestone is

a magnetized form of the iron oxide mineral magnetite. It has the property of attracting iron

objects. 

• The root of the English word magnet is from the Greek word magnes, probably

from Magnesia in Asia Minor, once an important source of lodestone.

1.2 MAGNETS

A magnet is a substance which can identify North-south directions. The substance has north-south pole.

Types of Magnets.

1.       Bar magnets.

2.       Horseshoe magnets.

3.    Compass needle.

        The end pointing North is North seeking pole.

The end pointing South is South seeking pole.

PROPERTIES OF MAGNETS.

1.      They can attract metals like iron, steel, cobalt and nickel.

2.      The attractive forces are concentrated at the two ends.

3.      When similar magnetic poles are brought near each other, they repel.

4.      When different magnetic poles are brought near each other, they attract.

1.3 THE FUNDAMENTAL LAW OF MAGNETISM.

• Like magnetic poles repel and unlike magnetic poles attract. 
• This means that two N poles or two S poles will push away from each other while a N pole and a S pole will be drawn towards each other.

1.4 MAGNETIC AND NON-MAGNETIC MATERIALS.

The materials/substances which can be attracted towards magnets are called MAGNETIC SUBSTANCES. The materials are themselves not magnets because they don’t attract each other e.g. iron, steel, cobalt, and nickel.

The materials which can’t be attracted towards a magnet are NON-MAGNETIC MATERIALS. E.g. wood, plastic, glass, zinc, carbon and rubber.

1.5 MAGNETIZATION.

Is the process of changing a magnetic material like steel, iron, cobalt to a magnet.

There are 3 main methods:

1.      STROKING METHOD.

Stroke the piece of steel with the north pole. Start at end A of the magnet and lift the magnet clear at end B of each stroke. Do this about 10 times in the same direction. Finally end A is magnetized. For double touch, use two opposite poles to stroke at the same time.

a.   Double touch 

In this case the steel bar will be magnetized with south pole at A and north pole at B.

2.    INDUCTION METHOD.

A magnetic material is magnetized by bringing it into contact with a magnet.

Disadvantages:

1.    Produces weak magnets not strong magnets.

2.    Tend to loose magnetism very fast as soon as they are separated from the magnets.

3.    ELECTRICAL METHOD.

Wind about 1 metre of insulated copper wire around a large nail AB, then connect the ends of the wire to the battery.

These magnets are called electromagnets.

ELECTROMAGNETS.

These are used in making devices such as electric bells, relay doors etc.

1.6 DEMAGNETIZATION

Demagnetization is the process of removing magnetism from a material.

Methods of demagnetization

1.    HAMMERING AND HEATING.

Place the magnet in East-West direction then heat it up and hammer it for some time.

2.    ALTERNATING CURRENT METHOD.

Coil a wire round the magnet and then connect the two ends of the wire to the two terminals of the battery. Then the connections to the battery terminal are quickly interchanged continuously for several minutes.

1.7 THE DOMAIN THEORY OF MAGNETISM

• The small portions of a magnetic material which behave like a magnet. These small portions are called DOMAINS. For a magnetic material, domains have North and south magnetic poles aligning in different directions.

• For this material to be magnetized, its domains have to be aligned in such a way that their North poles face one common direction and south poles face another common direction.
• Magnetic field: The region around a magnet where it has a magnetic effect.
• In any magnet there are several invisible lines that extend from north to south pole through the outside of the magnet and then move back to the north pole through the inside of the magnet forming closed loops. These imaginary lines are called magnetic lines of force which form magnetic field of a magnet.
• NB – When two similar poles are placed close to each other, there is a point somewhere between them at which the magnetic field lines do not pass. This point is called neutral point. OR When a pair of S-poles are kept close to each other.
• NB – A neutral point occurs because the magnetic lines of forces from similar poles do not join each other but repel and avoid each other.

• A neutral point can’t form between two unlike poles because the magnetic field lines from one pole join the lines from the other pole.

1.8 THE EARTH’S MAGNETISM.

• The earth has a magnetic field that extends from deep below earth’s surface to the sky. The magnetic north pole of the earth corresponds to real magnetic south pole and the magnetic south pole corresponds to real north pole.

-The vertical plane containing the axis of a freely suspended magnet at rest under action of earth’s field at any place is magnetic meridian.

-The vertical plane containing the earth’s axis of rotation at any place is called Geographic meridian.

-The angle between direction of alignment of the magnet and the geographic axis is magnetic declination.

-The horizontal direction in the magnetic meridian is magnetic dip-angle of dip.

1.9 APPLICATION OF EARTH’S MAGNETIC FIELD.

1.    The map readers use earth’s magnetic field to find locations of places.

2.    Map readers with a compass can locate north pole using the compass.

3.    It is used to detect minerals or rocks magnetized by earth’s field during solidification.

4.    Used to fix satellites with magnetometers to transmit the information about earth’s field high above earth’s surface.

1.9.1 USES OF MAGNETS.

1.    Magnetic recording media-tapes and cassettes.

2.    Making credit cards – ATM cards.

3.    Making speakers and microphones.

4.    In computers and televisions. – floppy and hard disks.

5.    In transformers.

6.    In electric motors.

7.    In generators.

8.    Used in hospitals when dealing with injuries caused by iron or steel.

9.    Used in steel works.


Comprehensive Physics notes prepared by Peter Lam Thuol

• Island. This is the piece of land which is completely surrounded by water eg Madagasca island country, Australia continent island, Ukerewe district island in Mwanza Tanzania
• Cape. This is the piece of land jutting into the sea eg Cape of Good Hope in South Africa
• Peninsula. This is the tract of land entering into the body of water eg Msasani peninsula in Dar es salaam Tanzania
• Gulf. This is the water inlets the  land eg Guinea gulf, Benguela gulf
• Strait. This is the narrow water path which separates one land mass from another eg Makasan strait inIndonesia
• Volcanic mountains§  Are mountains formed from the pilling up and cooling of hot molten lava and ashes that are thrown out from the interior of the earth. Examples of volcanic mountains are:-
• •                   Kilimanjaro, OldonyoLengai, and Meru in Tanzania.
  • Types of volcanic mountains
  • §  Volcanic mountains are classified into three types on the basis of their eruptions, namely
  • (i) Active volcanic mountains
  • (ii) Dormant/inactive/sleeping volcanic mountains
  • (iii) Extinct/dead volcanic mountains   
  • Active volcanic mountains
  • §  Are volcanic mountains which are still experiencing periodic eruptions and have erupted in recent periods. Examples of volcanic mountains include
  • §      Mount Vesuvius in Italy,
  • §      Mauna Loa in Hawaii
  • §      Taal volcano in Philippines
  • §      Mufumbiro in Uganda
  • §      Sakurajima mountain in Japan
  • §      Merapi mountain in Indonesia
  • §      Nyiragongo mountain in Congo DR
  • §      Cameroon mountain in Equatorial Africa
  • §      Piton de La Fournaise in reunion.  
  • §      Oldonyo Lengai in Tanzania
  •  
  • Dormant volcanic mountains
  • §   Are those which erupted once in the past but have remained in active for fairly a long period.
  • §  They are sleeping volcanic mountains which may become active once again. Examples of dormant volcanic mountains are:-
  • §      Kilimanjaro and Meru mountains in Tanzania
  • §      Keo mountain in Hawaii island
  • §      Elbrus mountain in Russia
  • §      Teide mountain in Spain
  • §      Rainier mountain in USA
  •  
  • Extinct/dead volcanic mountains
  • §  Are those volcanic mountains which were active but have not erupted for a very long time and do not show any sign of ever erupting again
  • §  Most these mountains have craters at their peaks, which are normally conical in shape which when craters are filled with water they form crater lakes for example lake Duluti and Ngorongoro both in Arusha Tanzania  and lake Nakuru in Kenya. Examples of extinct volcanic mountains include:-
  • §      Elgon and Kulal  mountains in Kenya
  • §      Ngorongoro and Rungwe in Tanzania
  • §      Chimborazo mountain Ecuador
  • §      Ben Nevis mountain in Scotland 

What is classification?

 It is the system of sorting out and placing organisms into different groups on the basis of their similarities and differences.

Types of classification:

There are two types of classification:

1. Artificial classification/system.
2. Natural classification/system.

Artificial system.

In this system only one or a small number of features are considered e.g. birds and bats all have the ability to fly. So by using this system, one can place the birds and bats in one group. Just by considering one feature that is the ability to fly. But in reality, birds and bats are classified into different groups.

Birds -> Aves.

Bats -> Mammals.

Natural system.

In this system, organisms are placed in their natural groups by:

1. Considering many features in common.
2. Characters that show:

Homology- Similarity of origin.

Analogy- Similarity of use.

Example of Homology:

The arms of a man, forelimbs of whales and wings of birds or bats are homologous because they have same order and pattern of bones. So these show that they have the same origin.

Example of Analogy:

The wings of birds and grasshoppers are analogous, because birds have internal skeleton (endoskeleton) and grasshoppers have external skeleton (exoskeleton). So these wings perform the same function but have different origins.

Importance of classification:

1. It helps us understand the characteristics of living things.
2. It enables man to identify and name numerous organisms.
3. It brings together living organisms with similar characteristics but separates those with different features.
4. It helps man arrange information about living organisms in an orderly manner to avoid confusion.
5. It makes the study of living organisms very easy.
6. It provides an organized system into which newly identified similar organisms can be fitted in future.

Advantages of Artificial classification.

1. Based on easy and simple characteristics.
2. Uses convenient and readily observable characteristics.
3. Based exclusively on arbitrary criteria.

Disadvantages of Artificial classification.

1. Unrelated organisms may be placed in the same group.
2. Tends to place closely related organisms into different groups instead of being grouped together.

Advantages of Natural classification.

1. Avoids confusion

-Unrelated organisms can’t be placed in the same group.

2. Accuracy.

-Closely related organisms with common characteristics features are placed in the same related group.

3. Universal.

-Because it uses same system of naming organisms.

Disadvantages of Natural classification.

It is not based on easy and simple characteristics but on evolutionary relationships.

NOMENCLATURE.

Is a scientific system of naming living organisms whereby each organism is assigned two names. The first name being the Genus and the second name is the species.

Note- Bi means two, Nomino means name.

So Binominal means two names.

Rules of binominal nomenclature:

1. Only the first letter of the genetic name is capitalized and then the whole genetic name is underlined eg. Homo.
2. The first letter of the species name is never capitalized, and then the whole species name is underlined eg. sapiens. So the scientific name for man is Homo – genus, sapiens – species.
3. If the scientific name is written in italics, then it should never be underlined, but other rules remain the same.

Eg: Homo     sapiens    (Romanic)

Homo sapiens (Italic)

Examples of scientific names:

Man – Romanic:Homo  sapiens.

Italic:Homo sapiens.

Elephant – Romanic:Loxodorita   africane.

Italic:Loxodorita africane.

Maize – Romanic:Zea   mays.

Italic:Zea mays.

Dog – Romanic:Canis  familiasis.

Italic:Canis familiasis.

Leopard:Panthea pardus.

Italic:Panthea pardus.

Lion – Romanic:Panthea leo.

Italic:Panthea leo.

 Ranks of classification (Toxonomic.)

Ranks are the groups into which organisms are placed as the matter of convenience based on easily observable features, that are shared in common for group identification.

These are seven major ranks of classification, they are:

Genus:Is a group of organisms with a large number of similarities but unable to interbreed successfully.

Species:Is a group of organisms which are capable of interbreeding together and produce fertile offsprings.

THE MAJOR KINGDOMS.

There are five major kingdoms of living things. These major kingdoms exclude a virus. Because the virus is between living and non-living things. The major kingdoms are:

1. Kingdom Monera.
2. Kingdom Protoctista.
3. Kingdom Fungi.
4. Kingdom Plantae.
5. Kingdom Animalia.

THE VIRUS.

Is a chemical between living and non-living things.

Characteristics of a virus:

1. They are living and non-living things.
2. They are RNA or DNA.
3. They can multiply only in living cells.
4. Each virus is specific in its host and even of the type of a cell within its host.
5. They are the smallest living or non-living organisms about 50 times bacteria.
6. They can only be seen under electronic microsopes.

Bacteriophage

Economic importance of virus.

1. They cause plant diseases.
2. They cause animal diseases.
3. They attack and kill bacteria.
4. Used in making vaccines etc.

Kingdom Monera (Bacteria)

General characteristics.

1. They are unicellular and very small organisms.
2. They have cell wall made up of polysaccharides, cellulose, fat, proteins and chitin.
3. They store food in form of glycogen, fats, proteins, sometimes sulphur.
4. They are heterotrophic organisms.
5. They are obligate bacteria’s- respires aerobically. Facultative bacteria- respire anaerobically, micro-aerophilous- respire in very low oxygen.
6. They are capable of producing toxins which can poison other organisms.
7. Bacteria can grow best in 30º-37ºc, 15º-20ºc, -2º – -9ºc, 60ºc and above.
8. They reproduce by binary fission.
9. They live in soil, dust, water, air, animals and plants. In addition to that, bacteria’s are enormous e.g. in 1cm3 of fresh milk, it contains more than 300,000,000 bacterias.
10. Together with fungi, they cause decay of organic materials and hence recycling of nutrients.
11. They are prokaryotic.

Forms of bacteria.

Coccus:It causes sore throat.

Diplacoccus:Causes pneumonia.

Streptococcus:Causes sore throat.

Staphylococcus:Causes boils.

Spirillium:Causes Syphilis.

Bacterium:Bacillus anthrax:Causes anthrax.

Economic importance of bacteria:

1. Production of antibiotics.

2. Used in sewage (They decompose pollutants)
3. Used in cheese and butter making.
4. Used in vinegar and alcohol production.
5. Used in fermentation process etc.

Kingdom Protoctista.

Members of these kingdom resembles the ancestors of plants, animals and fungi. These are the algae, protozoa etc. In protozoa we have amoeba and paramecium etc. other members of this kingdom are euglena and trypanosome. Algae contains red, brown and green algae.

General characteristics of Kingdom Protoctista:

1. Are eukaryotic organisms.
2. Many are unicellular.
3. It includes organisms which resembles early plants (algae), early animals (protozoa) and early fungi (Oomycetes).
4. Are the links between prokaryotes and modern eukaryotes.
5. They locomote by the use of cilia or flagella.
6. They have a contractile vacuole for excretion.
7. They feed holophytically (This means that they feed autotrophically e.g. euglena and heterotrophically e.g. amoeba and paramecium.)
8. They reproduce by binary fission and multiple division which means sexual and asexual.
9. They contain a clear and visible nucleus.
10. The locomotary structures are:

Amoeba- Pseudopolis.

Paramecium- Cilia.

Euglena- flagella.

Trypanosome- flagella.

Plasmodium- flagella.

Economic importance of Kingdom protoctista.

1. Causes diseases e.g. sleeping sickness in man by a trypanosome transmitted by a vector called tsetse fly.
2. Plasmodium causes malaria in man transmitted by female anopheles mosquito.

There are of 4 species:

Plasmodium vivax.

Plasmodium malariae.

Plasmodium ovale.

Plasmodium falciparum.

1. (a) Define the following terms

• Mole
• Molar mass
• Relative atomic mass

   (b)Ammonic (NH3), Hydrogen (H2), Carbondioxide (Co2) are gases at room temperature 

1. Which of the gases are compounds
2. Which of the gases are elements 
3. Calculate the mass of one mole of Amononic molecules

  (c) 1. Calculate the molar mass of Na2Co3. 10H2O

        2. What amount of substance is present in 180g of Carbondioxide? 

WEB DEVELOPMENT

Introduction to webpage design

      explain the concept of a webpage

      create a web page

      explain web page preview

publishing web page

      explain the concepts of a publishing a webpage

      outline the importance of publishing a webpage

      explain the procedures of transferring a webpage to web server

      distinguish between webpage and websites

      access information on a website

What is a webpage?

Webpage is a document which is written in HTML (hypertext markup language) and is translated by  a Web browser.  Eg. Opera, Mozilla, internet explorer etc

Web page is what makes up the World Wide Web. Web page can either be static or dynamic. 

Static page shows the same content each time when it is viewed. Dynamic page has content that can change each time when it is accessed. NB the browser translates the HTML 

Or

A web page or webpage is a document which is written in Hypertext Markup Language

    (HTML) that is accessible through the Internet or other network using a browser. 

A web page is accessed by entering a URL (universal resource locator) addresses through a web browser.

What is a web browser?

A web browser is software that displays a web page on a monitor or mobile devices.  Example of a web browser internet explorer, opera, Mozilla Firefox etc

On a network, a web browser can retrieve a web page from a remote web server.

What is a domain name?

A domain name is a website name. A domain name is the address where Internet users can access a website. A domain name is used for finding and identifying computers on the Internet. Computers use IP addresses, which are a series of number. However, it is difficult for humans to remember strings of numbers. Because of this, domain names were developed and used to identify entities on the Internet rather than using IP addresses.

Domain names are formed by the rules and procedures of the Domain Name System (DNS). Any name registered in the DNS is a domain name. Every domain name is unique. No two websites can have the same domain name

Example yahoo.com ,google.com,studentgiri.com

In Google.com, .com is the TOP LEVEL DOMAIN NAME.

What is URL means?

URL stands for Universal/uniform Resource Locator. It is the address of a web page. Each page has its own unique web address (URL). This is how your computer locates the web page that you are trying to find.

An example of a URL is: http://funbrain.com/index.html. In this example URL, funbrain.com is called the domain name. The "index.html" refers to the specific page.

So Structure of a URL is like this:

http protocol :// domain / path
It is combination of protocol, domain and path (sometimes port also). Here port is hidden as default port with http protocol is always 80.

Elements of a webpage.

A web page may contain different elements/ different types of data such as

     Text/word,

     sound,

     video, 

     graphics, and

     hyperlinks to other web pages and files.

When was the first web page created?

 The first web page was created at  CERN by Tim Berners-Lee and  put online August 6, 1991

Different between a webpage and a website.

A Web site is a collection of one or more pages which are linked  together by using hyperlinks

Hyperlinks are represented by specific texts or images that  enable a user to navigate /move/ transfer from one web page to another.

Whereas 

Webpage is a document which is written in HTML (hypertext markup  language) and is translated by  a Web browser.  Eg. Opera,mozilla,internet explorer

A website may have a home page, a contact Us page, a Schedule page, a login page and so on and so forth. All of them together would be the site.

When we type an address in the address bar of some browser like Internet Explorer ,we are referring actually to the website or the address of the website which in technical terms is called URL or Uniform Resource Locator.

Thus, it is just like you ask what the difference between a book and papers is.

¨  This is a website of Necta

¨  www.necta.go.tz

What is a hyperlink?

Hyperlink is an element in an electronic document that links to another place in the same document or to an entirely different document. Typically, you click on the hyperlink to follow the link .  Or

A hyperlink is a word, phrase, or image that you can click on to jump to a new document or a new section within the current document. Hyperlinks are found in nearly all Web pages, allowing users to click their way from page to page. Text hyperlinks are often blue and underlined.

Take away

1.What is the difference between a website and a web page?  2 marks

2.What is a hyperlink? 1 mark

3.List 4 contents/elements of a webpage.

    2 marks

4.What is an HTML tag? Give 4 examples 3 marks

5. List 3 features of tags 1.5

 6. What are the two categories of tags 2 marks

7.What is the function of a hyperlink?

Today I'm Going To Teach You or give This Helpful piece Of Information To You About the Introduction To Physics .And Let's Start by looking... What physics is all about! 

1. Protagonist character. (Hero/ heroine).