Fundamentals of Electricity and Electromagnetism

Basic Concepts of Electricity

• Electricity relates to physical phenomena associated with presence and flow of electric charges.
• It manifests in phenomena like lightning, static electricity, electromagnetic induction, and electric current flow.

Electrification Processes

• Electrification involves the loss or gain of electrons.
• Electrons must have mobility for electrification to occur.

Electrical Conductors and Insulators

• Electrical conductors permit the movement of electrical charges, metals are examples of this.
• Electrical insulators impede the movement of electrical charges, glass, plastic, and silk are examples of this.

Theory of Electromagnetism

• Magnetism and electricity have a close relationship.
• Natural or artificial magnetism enables the obtainment of plentiful electricity simply and economically.
• James Clerk Maxwell, a Scottish mathematician, was the first to explain the relationship between electricity and magnetism around 1870.

Electromagnetism

• Magnetism from electricity is called electromagnetism
• Electric generators like dynamos or alternators, transformers, relays, and motors are common industrial applications.

Foundations of Electromagnetism

• Electromagnetism principles hold that an electric current passing through a coiled wire around a support creates a magnetic field.
• The magnetic field intensity intensifies as the number of coil loops and the current strength increase.

Applications of Electromagnetism

• The operation of alternators, dynamos, or magnetic flywheels relies on the principle of induced current in a winding exposed to magnetic field variation.

Electrical Generators: Dynamo and Alternator

• Michael Faraday found that moving an electrical conductor within a magnetic field created voltage.
• An electric current flowed when the circuit closed with a receptor.

Dynamo

• A Dynamo has collectors that rotate with each end of the loop, plus fixed brushes, facilitate extracting the generated current.
• The collectors present in dynamos are segmented.

Alternator

• Similarly to the dynamo, an alternator contains a brush that changes polarity in each complete loop rotation.
• Alternators are similar to dynamos with uncut collectors.

Electrical Machines

• Electrical machines generate, harness, or transform electrical energy.
• Generators convert mechanical energy into electrical energy.
• Motors convert electrical energy into mechanical energy.

Electric Motors

• Electric motors are rotating electrical machines that transform electrical energy into mechanical energy
• Electric motors are advantageous due to their economy, cleanliness, convenience, and operational safety.
• An electric motor bases its operation on attraction and repulsion forces between a magnet and a coil through which an electric current moves.
• Modern electric motors have multiple loops, called winding, in the rotor (rotating part) and a large magnet, the stator, in the motor's fixed part surrounding the rotor.

Electricity Production

• Post understanding the principles of generating electricity from magnetic fields and electron movement, this knowledge transfers to commercial electricity production.
• Electric plants capitalize on different energy sources: biogas, geothermal, wind, thermal, and hydroelectric plants.

Electric Current

• There are two types of electric current:
  • Alternating Current
  • Direct Current.

Direct Current (DC)

• In direct current, abbreviated as DC, charges move in one direction
• Batteries produce direct current.

Alternating Current (AC)

• Charges flow in alternating directions in alternating current, abbreviated as AC
• The frequency, measured in hertz (Hz), details how many times the polarity changes per second in a circuit.

Potential Difference

• The potential difference, or voltage, between two points is the energy needed to move a positive charge from one point to another.
• The unit of measurement is the volt (V).

Voltmeter

• Voltage, like water pressure in a pipe, drives electric current flow through a conductor.
• A voltmeter measures potential difference, tension, or voltage, this device connects in parallel in a circuit.

Current Intensity

• Current intensity quantifies electric charge flow through a conductor per unit of time.
• The unit of current intensity is the ampere (A) equaling one coulomb of charge per second.
• An ammeter measures electrical current, is wired in series within the circuit.

Electricity Production Based on Fossil Fuels

• Generating electricity using fossil fuels is thermal plant, irrespective of the fuel (gas, coal, etc.).

Key Elements of a Thermal Power Plant

• A thermal power plant turns fuel to heat water in a boiler, creating steam to drive turbines which subsequently power a generator.
• The power production then goes through a transformer. The voltages are increased and sent to the electrical grid at 25 to 132 kilovolts, although the amount varies.
• The steam is then treated in a condensation tower for reuse
• Long-distance high-voltage cables justify increased transmission voltages, mitigating copper-induced resistance and voltage drops from supply points to distribution hubs.

Energy Demands and Sources

• Global energy demands have sustained at 14%, boosted by population growth, advancing industrialization, and better lives in developing countries.
• Primary energy sources are fossil fuels, nuclear fission, and renewables.

Alternative Energy Sources

• Biogas, geothermal, wind, thermal, and hydroelectric sources are types of energy that can be harnessed to generate electricity.

Basic Computer Concepts, Functional Model

• A functional computer system comprises several interconnected elements enabling its function.
  • Central Processing Unit (CPU)
  • Memory (RAM and secondary storage)
  • Input/Output Devices
  • Buses
  • Operating System.

Central Processing Unit (CPU)

• The CPU is the system's brain, performing data processing operations.

Memory

• Divided into main memory (RAM) and secondary memory (hard drives, SSDs, etc.).

Input/Output (I/O) Devices

• Enable communication with the user and other systems.

Buses

• Buses facilitate data transfer between system components.

Operating System

• The operating system (OS) manages hardware and software resources.

The Importance of Computers in Society

• Society immerses itself in applying information and communication technologies, calling for participation without marginalization.
• It is now essential to be competent in these technologies.

Computer Variability

• Computer hardware varies in shape, size, capacity, and complexity, yet these possess a common element: computers.
• Understanding the fundamentals behind computers establishes a foundation for computer aptitude.

Hardware

• Hardware refers to physical devices or equipment involved in system operation.
• Computers, printers, scanners, digital cameras, barcode readers, and comms gear are all hardware.

Software

• Software contains instructions to perform a process, hardware relies on software for functioning.
• Logical software components are instructions or programs.

System Software

• System software administers and controls hardware operations.
  • Operating systems
  • Utilities.
• MS Windows, Linux, Unix, and Mac OS are examples of operating systems for computers. Symbian, iPhone OS, Android, BlackBerry, and Windows Phone are used for mobile phones.
• Utility software supports OS functions, providing features for partitioning hard drives, installing/uninstalling programs, and compressing/decompressing files.

Operating System (OS)

• An OS provides programs with a streamlined computer model
• It oversees resource management.
• There are two OS modes of operation: kernel and user modes.
• As the fundamental software piece, the OS operates in kernel mode.
• A system in kernel mode exercises full hardware access and can execute machine instructions.

Source Code

• An OS source code such as Linux or Windows contains 5 million code lines.
• User programs include an interface, libraries, and basic application software, these are 10 to 20 times that amount.

Application Software

• Application software runs user activities, subdividing into general purposes, specific purposes, custom, communication, programming and development languages.

Interfaces

• An interface connects two systems or components to enable communications in different levels allowing information exchange.

Graphical User Interface (GUI)

• A GUI is an environment using graphic images and objects to represent information and actions, facilitating machine-user interaction.

Command Line Interface (CLI)

• A CLI employs text for OS and software operation, enabling users to respond by inputting commands within the interface and receiving responses.

Data

• Data describes distinct facts or figures lacking inherent meaning.

Information

• Information describes or specifies an object or event.
• Data sets process and yield information.

Basic Computer Operation

• Computers works when processes perform: Input, Process, and Output
  • The input unit initiates the process, taking in user entered data and routing it to the memory and control unit.
  • The memory unit then divides this data into cells or positions for direct use by the control unit.
  • The micro processor or CPU has a control unit or CU which then has and arithmetic-logic unit ALU to process and solve the information.
  • The control unit completes the operation by routing data back to the output unit giving the user access.

Elements of a Computer

• A computer performs four basic functions: receiving, providing, processing, and storing data.
• Hardware includes: CPU, memory, and input/output (I/O) devices.

Cabinet

• Cases hold components such as the CPU, and come as vertical, horizontal, or monitor-integrated.
• They house power sources, drive bays, CDROM drives, external connection points, and speakers.

Motherboard

• Installed in the case/cabinet, the motherboard is a printed circuit holding electronic circuits.
• It facilitates communication pathways between various computer components.
• The CPU microprocessor integrates in the motherboard
• Other modules on the motherboard: ROM, where RAM modules install, storage controllers, expansion slots, and communication ports.

Universal Serial Bus (USB) Port

• It provides high-speed I/O and low costs for devices that once necessitate individualized integration cards. USB enables connections to a large array of devices that are not more than five meters away.
• Key devices such as; keyboards, modems, mouses, digital scanners and cameras.
• USB support ease of connectivity such as; Plug and Play, it eliminated the need to restart the PC before peripheral connectivity.

Processor

• The CPU is the computer's brain, a small yet powerful micro processing chip.
• The CPU's brand, model, version, and speed define the computing speed and software compatibility.
• Intel and AMD are popular brands for processors.

Memory

• The area where a PC stores, retrieves and works with all running operations directly from the CPU
• Two type of memory are used:
  • Primary memory such as: (ROM) or Read Only Memory, or (RAM) Random Access Memory
  • Secondary memory is a permanent device.

Computer Function Memory

• The memory is divided based on functions in terms of the processing speed.
• Temporal Memory
• Main Memory (RAM) is for temporary data and runtime operations.
• Cache memory stores user frequently used data.
• EEPROM(Electrically Erasable Programmable Read-Only Memory) use electrical signals to erase or read.
• Permanent Memory
  • Hard-disk Drives (HDD)'s use spinning hard disks with heads that read and write data.
  • Magneto-Optical Drives stores data by using magnets and laser
  • (SSD)'s the disk is a Solid State Drive, these disk as solid and state the PC and is therefore mechanical free.

Input Devices

• Users input data or commands into input devices
• Common input devices include the keyboard and mouse.

Keyboard

• The keyboard provides instructions to the computer and has a layout similar to the QWERTY system common to typewriters.

Mouse

• A hand-conforming mouse graphically selects on-screen objects on your monitor for pointing, clicking and dragging, is a pointing gadget.

Output Devices

• Output devices show the results of the computing.
• A monitor can show all forms of input and output. Also a printer outputs data as hard copies.

Monitor

• This is for showing input and output on screen.
• Important due to interacting with the process in a familiar language.

Printers

• Printing allows a hard copy to be produced, there are two technologies: Laser printing ,and inkjet both allow full color print.

Communication Devices

• A computer that communicates are not seen as isolated, these devices are important to communication
• Computer communicate through modems is that are connected by a shared red

Network

• More than two interconnected parts make up a part of a network, sharing a computer to coordinate cable system and protocols.

Classification of Personal Computers

• Types of Personal Computers are designed for specific use
• Desktop computers set in a fixed area and have modular components.
• Laptops are cordless and come along in batteries.
• Tablets: Portable and utilize and utilize optimised programs and systems.
• Mini Pc and NUC, these devices are small and portable using less hardware to save energy.

Networks

• Types of Networks:
• LANs or Local Area Network: These are mostly privately used, it is set to a limited areas to save cabling.
• WANs or Wide area network: The internet using both public data and private data to communicate from other districts.

Systems of an user

• Types Of systems that use the same use, single user and Multiple User systems.
• Single use system, it is one use and can only be accessed by one user at same access time
• Multi User systems: A computer with Linux systems can process one or more users to access certain information.