TOPIC 1: NUMBERS We know that when we count we start 1,2 …. . But there are other numbers like 0, negative numbers and decimals. All these types of numbers are categorized in different groups like counting numbers, integers,real numbers, whole numbers and rational and irrational numbers according to their properties. all this have been covered in this chapter Base Ten Numeration Numbers are represented by symbols called numerals. For example, numeral for the number ten is 10. Numeral for the number hundred is 100 and so on. The symbols which represent numbers are called digits. For example the number 521…
Author: Msomi Bora
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TOPIC 7: GEOPHYSICS Geophysics is a branch of science that deals with the physical, chemical, geological, astronomical and other characteristic properties of the earth.It deals with geological phenomena such as the temperature distribution of the earth’s interior, the source, configuration and the geomagnetic field. Structure and Composition of the Earth The Structure of the Earth Describe the structure of the earth The structure of the earth is composed of three major zones arranged in concentric manner. These are crust, mantle and core. The crust Is the outer solid layer o the earth.It is extremely thin(5 to 15km) compared to the…
TOPIC 6: ELEMENTARY ASTRONOMY Introduction to Astronomy The Concept of Astronomy Explain the concept of astronomy Astronomy is a branch of science which deals with the study of origin, evolution, composition, distance and the motion of all bodies and scattered matter in the universe. Universe is the totality of space and time together with matter and energy. Astronomers are the people who deals with the study of astronomy. The Importance of Astronomy in Everyday Life Explain the importance of astronomy in everyday life Importance of astronomy include: It was the earliest method of measuring time. It was used to develop…
TOPIC 5: ELECTRONIC Semi Conductors The Concept of Energy Band in Solids Explain the concept of energy bands in solids In solid-state physics, the electronic band structure (or simply band structure) of a solid describes those ranges of energy that an electron within the solid may have (called energy bands, allowed bands, or simply bands) and ranges of energy that it may not have (called band gaps or forbidden bands). Band theory derives these bands and band gaps by examining the allowed quantum mechanical wave functions for an electron in a large, periodic lattice of atoms or molecules. Band theory has been successfully used to explain many physical properties of…
TOPIC 4: THERMIONIC EMISSION Thermionic emission is the discharge of electrons from heated materials, widely used as a source of electrons in conventional electron tubes (e.g., television picture tubes) in the fields of electronics and communications. The phenomenon was first observed (1883) by Thomas A. Edison as a passage of electricity from a filament to a plate of metal inside an incandescent lamp. The classical example of thermionic emission is the emission of electrons from a hot cathode into a vacuum (also known as thermal electron emission or the Edison effect) in a vacuum tube. The hot cathode can be…
TOPIC 3: RADIOACTIVITY The Nucleus of an Atom The Structure of the Nucleus of an Atom Describe the structure of the nucleus of an atom The word atom is derived from the Greek word ‘atomos’ which means indivisible. The Greeks concluded that matter could be broken down into particles too small to be seen. These particles were called atoms. Atoms are composed of three type of particles: protons, neutrons, and electrons. Protons and neutrons are responsible for most of the atomic mass. The mass of an electron is very small (9.108 X 10-28 grams). Both the protons and neutrons reside in…
TOPIC 2: ELECTROMAGNETISM Magnetic Fields due to a Current-carrying Conductor How Electric Current Produce a Magnetic Field Explain how electric current produces a magnetic field Electromagnetism is the effect produced by the interaction of an electric current with a magnetic field. The interaction can result in a force on the conductor carrying the current. If, on the other hand, a force is applied to a conductor (with no current) in a magnetic field the resulting movement can result in a current being noticed in the conductor. When the switch is closed an electric current flows through the conductor. The electric…
topic 1: WAVES Introduction to Waves The Concept of Wave Explain the concept of a wave A wave is a disturbance that travels through a medium from one location to another location. Waves are classified into; transverse waves: Waves which have their direction of motion perpendicular to the vibration of the particles e.g water waves. longitudinal waves: Waves have their direction of motion parallel to the direction of the vibration of the particles e.g sound waves. Consider a slinky wave as an example of a wave. When the slinky is stretched from end to end and is held at rest,…
TOPIC 9: THERMAL CURRENT ELECTRICITY Electromotive force (emf) and potential difference (pd) The Concept of Electromotive Force (emf) and Potential Difference (PD) Explain the concept of electromotive force (emf) and potential difference (pd) Potential difference (P.d) is the difference in potential between two charged points of conductor. It is measured in volts with the unit V. Electromotive force (e.m.f) is the voltage developed by any source of electrical energy such as a battery or dynamo. It is generally defined as the electrical potential for a source in a circui. It is measured in volt with the unit V. Internal Resistance (r)is…
TOPIC 8: VAPOUR AND HUMIDITY Vapour The Process of Evaporation of Liquid Explain the process of evaporation of liquid Vapours These are molecules which escape into the atmosphere after liquids are heated. When a liquid is heated strongly then molecules tends to escape ( those molecules are called vapour). Most liquids evaporates at any temperature however liquids may vary in the rate at which they evaporate at ordinary temperature. Alcohol and ether evaporate rapidly but lubricating oil and mercury hardly evaporate. Evaporation of a liquids result in the formation of vapour. Factors Affecting Evaporation of a Liquid Identify factors affecting…