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Electric Circuits and Field   BASIC CONCEPTS An electric circuit is a path in which electrons from a voltage or current source flow. The point where those electrons enter an electrical circuit is called the "source" of electrons. The point where the electrons leave an electrical circuit is called the "return" or "earth ground". The exit point is called the "return" because electrons always end up at the source when they complete the path of an electrical circuit. The part of an electrical circuit that is between the electrons' starting point and the point where they return to the source is called an electrical circuit's "load". The load of an electrical circuit may be as simple as those that power home appliances like refrigerators, televisions, or lamps or more complicated, such as the load on the output of a hydroelectic power generating station. At the heart of these electrical devices are made by assembly of electrical components. These component are classified in two categories i.e., active components and passive components. are components are: semiconductors, transistors, diodes and triodes, current source, voltage source. However, these devices could not function without much simpler components known as passive component these include resistors, capacitors and Inductors   RESONANCE Resonance in electrical circuits consisting of passive and active elements represents a particular state of the circuit when the current or voltage in the circuit is maximum or minimum with respect to the magnitude of excitation at a particular frequency, the circuit impedance being either minimum or maximum at the power factor unity.   Series Resonance     Resonance Properties of Series RLC Circuit  

The applied voltage and the resulting current are in phase which also mean that the p. f. of the RLC series resonant circuit is unity.

The net reactance is zero at resonance and impedance does have the resistive part only.

The current in the circuit is maximum and is (V/R) A.

At resonance, the circuit has got minimum impedance and maximum admittance.

Frequency of resonance is given by \[{{f}_{0}}=\frac{1}{2\pi \sqrt{LC}}Hz\]

Q factor of series resonant circuit is given by

\[Q=\frac{1}{{{\omega }_{0}}RC}=\frac{1}{\frac{1}{\sqrt{LC}}RC}=\frac{1}{R}\sqrt{\frac{L}{C}}.\] \[Also,\,\,Q\,=\frac{{{f}_{0}}}{Bandwidth}=\frac{\operatorname{Re}sonant\,\,frequency}{Bandwidth}\]   Parallel Resonant     Properties of Parallel Resonant LRC Circuit  

Power factor is unity

Current at resonance is [V/ (L/CR)] and is in phase with the applied voltage. The value of current at resonance is minimum.

Net impedance at the resonance of parallel circuit is maximum and equal to (L/CR)\[\Omega \]

The admittance is minimum and net susceptance is zero at resonance.

The resonant frequency of this circuit is given by- \[{{f}_{0}}=\frac{1}{2\pi }\sqrt{\frac{1}{LC}-\frac{{{R}^{2}}}{{{L}^{2}}}}\]

  Resonance Between Parallel RC and RL Circuit   Let        \[{{Y}_{1}}\]= admittance of \[{{R}_{1}}C\]circuit \[{{Y}_{2}}\]= admittance of\[{{R}_{2}}L\] circuit Y= net admittance \[={{Y}_{1}}+{{Y}_{2}}\]             \[=\left[ \frac{{{R}_{1}}}{R_{1}^{2}+X_{C}^{2}}+\frac{{{R}_{2}}}{R_{2}^{2}+X_{L}^{2}} \right]+j\,\,\left[ \frac{{{X}_{C}}}{R_{1}^{2}+X_{C}^{2}}-\frac{{{X}_{L}}}{R_{2}^{2}+X_{L}^{2}} \right]\] Important Point  

• Circuit will be resonant for any frequency provided

\[{{R}_{1}}={{R}_{2}}=\sqrt{L/C}\]

• Resonant frequency,

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IT Literacy   Literacy is being able to read, write, listen, speak, view and represent while thinking critically and creatively about ideas and information. Literacy enables us 10 understand ourselves and the world around us, to interact with others and to share thinking. Now days, IT Literacy programmed are initiated by the Central Govt. and State Govt. and made it compulsory to create IT skilled professionals in their recruitment policies. IT literacy is also known as computer Literacy.   Computer Literacy Computer literacy is the ability to use computers and related technology efficiently, with a range of skills covering levels from elementary use to programming and advanced problem solving. By another measure, computer literacy requires some understanding of computer programming and how computers work.   10 things we have to know to be computer literate:  

Search Engines

Using a search engine is more than typing in the address, putting a couple of keywords into the big text box, clicking Search, and choosing the first result. While that may work, it won't give you the best results much of the time. Learning the advanced search, Boolean operators, and how to discern good results from bad results goes a long way toward enabling you to use a computer as a powerful research tool.  

Word processing

Word processing is one of the oldest uses for a computer. And it continues to be extremely important, even though in many ways its functions have been put into other applications. (For example, people may write more emails than documents, but the task is nearly identical.) It is tough to claim to be computer literate if the basic functions of word processing - like spell check, table creation, and working with headers - are outside your capabilities.  

Spreadsheets.

A spreadsheet is an interactive computer application for organization, analysis and storage of data in tabular form. Spreadsheets are developed as computerized simulations of paper accounting worksheets. The program operates on data entered in cells of a table. Each cell may contain either numeric or text data, or the results of formulas that automatically calculate and display a value based on the contents of other cells. A spreadsheet may also refer to one such electronic document.  

Browser basics

Mastering techniques like opening links in new window using bookmarks, editing URLs to perform navigation clearing the browser cache, and understanding common error messages will give us access to a world of unlimited information instead of keeping we stuck with only what web site designers make obvious.  

Virus/malware scanning

  Much of typical computer maintenance is automated unneeded at that point, but it is still essential to understand how to check a system for nasty bugs, spyware, and other malicious applications. While the scanning tools come with real-time monitors, something can still slip onto the system before the scanner has the right filter for it. So it's critical know how to trigger a manual virus/malware scan, as more...

Environmental Education  Environmental education is a process that allows individuals to explore environmental issues, engage in problem solving, and take action to improve the environment. As a result, individuals develop a deeper understanding of environmental issues and have the skills to make informed and responsible decisions. The components of environmental education are:

• Awareness and sensitivity to the environment and environmental challenges
• knowledge and understanding of the environment and environmental challenges
• Attitudes of concern for the environment and motivation to improve or maintain environmental quality
• Skills to identify and help resolve environmental challenges
• Participation in activities that lead to the resolution of environmental challenges

Environmental education does not advocate a particular view point or course of action. Rather, environmental education teaches individuals how to weigh various sides of an issue through critical thinking and it enhances their own problem-solving and decision-making skills.   Concept of Environment Education Environment is the source of all our needs. It provides all the things for our livelihood. However, the activities of human being are not environment friendly. Environment Education is the educational process that teaches everything about the environment It teaches us the way to keep our environment clean and preserve the environmental elements.   The importances of environment education are:

• Develops the concept of wise use of natural resources: Many people do not have the concept that their activities interfere the status of the environment. They use the natural resources randomly. They do not even know the hazards of their malpractices. They do not try to replace the lack by the means of afforestation and other regeneration programmes. Environment education teaches people about wise use of natural resources.
• Encourage for the creation of healthy environment: Healthy environment refers to the environment which is free from the dust, germ and other elements that cause many hazardous diseases. Environment education provides knowledge about various things such as personal hygiene, environmental sanitation and other topic related to healthy environment which prompts us to create a healthy environment.
• Cultivates awareness about environmental: Environmental degradation has been a great threat to the existence of all flora, fauna and human beings. Environment education gives knowledge about environmental pollution, create awareness.
• Helps to provide integrated knowledge: Environment education incorporates the elements that are related with health and population education. It helps to control the rapidly growing population, to keep the surrounding clean and to give emphasis on personal hygiene.

  The Scope of Environment Education The scope of environmental education can be divided into biological, physical and sociological aspects. They are described below:

Biological aspect: Biological aspects are one of the most important aspects of environmental education. Human being, animals, birds, insects, microorganism, plants are some of the examples of biological aspects.

Physical aspect: It can be further divided into natural aspects and human- made aspects. Air, water, land, climate etc are included in natural physical aspects. Likewise, Human made physical aspects cover all human made things such as roads, buildings, bridges, houses more...

Occupational Health and Safety   Occupational health and safety is a discipline with a broad scope involving many specialized fields. In its broadest sense, it should aim at

• the promotion and maintenance of the highest degree of physical, mental and social well-being of workers in all occupations
• the prevention among workers of adverse effects on health caused by their working conditions
• the protection of workers in their employment from risks resulting from factors adverse to health
• the placing and maintenance of workers in an occupational environment adapted to physical and mental needs
• the adaptation of work to humans.

In other words, occupational health and safety encompasses the social, mental and physical well-being of workers that is the whole person". Successful occupational health and safety practice requires the collaboration and participation of both employers and workers in health and safety programmed, and involves the consideration of issues relating to occupational medicine, industrial hygiene, toxicology education, engineering safety, ergonomics, psychology, etc. Occupational health issues are often given less attention than occupational safety issues because the former are generally more difficult to confront. However, when health is addressed, so is safety, because a healthy workplace is by definition also a safe workplace. The converse, though, may not be true - a so-called safe workplace is not necessarily also a healthy workplace. The important point is that issues of both health and safety must be addressed in every workplace.   Important of Occupational Health and Safety Work plays a central role in people's lives, since most workers spend at least eight hours a day in the workplace, whether it is on a plantation, in an office, factory, etc. Therefore, work environments should be safe and healthy. Yet this is not the case for many workers. Every day workers all over the world are faced with a multitude of health hazards, such as:

• dusts
• gases
• noise
• vibration
• Extreme temperatures.

Unfortunately some employers assume little responsibility for the protection of workers' health and safety. In fact, some employers do not even know that they have the moral and often legal responsibility to protect workers. As a result of the hazards and a lack of attention given to health and safety, work-related accidents and diseases are common in all parts of the world.   Costs of Occupational Injury/ Disease Work-related accidents or diseases are very costly and can have many serious direct and indirect effects on the lives of workers and their families. For workers some of the direct costs of an injury or illness are:

• the pain and suffering of the injury or illness
• the loss of income
• the possible loss of a job
• health-care costs.

It has been estimated that the indirect costs of an accident or illness can be four to ten times greater than the direct costs, or even more. An occupational illness or accident can have so many indirect costs to workers that it is often difficult to measure them. more...

Levers and Simple Machines  LEVER A lever is simply a plank or ridged beam that is free to rotate on a pivot. It is perfect for lifting or moving heavy things. It is a very usefull simple machine, and we can find them everywhere. Good examples of levers include the seesaw, crowbar, fishing-line, oars, wheelbarrows and the garden shovel.   Parts of a Lever Levers have four very important parts - the bar or beam, the fulcrum die pivot or the turning point), effort (or force) and the load.       The beam is simply a long plank. It may be wood, metal or any durable material. The beam rests on a fulcrum (a point on the bar creating a pivot). When we push down one end of a lever, we apply a force (input) to it. The lever pivots on the fulcrum, and produces an output (lift a load) by exerting an output force on the load. A lever makes work easier by both increasing input force and changing the direction of input force.   The Three Lever Classes The parts of the lever are not always in the same arrangement. The load, fulcrum, and effort may be at different places on the plank.   Class One Lever In this class, the Fulcrum is between the Effort and the Load. The mechanical advantage is more if the Load is closer to the fulcrum. Examples of Class One Levers include seesaws, boat oars and crowbar     Class Two Lever In this class, the Load is between the Effort and the Fulcrum. The mechanical advantage is more if the load is closer to the fulcrum. Examples of Class Two Levers include wheelbarrows.   Class Three Lever In this class, the Effort is between the Load and the Fulcrum. The mechanical advantage is more if the effort is closer to the load. An example of Class Three Lever is a garden shovel.   MACHINE A machine is any device that does work. Machines make our lives easier because they reduce the amount of energy, power, and time we need to get one thing done by magnifying our input force. Machines come in many sizes, shapes and forms. Some machines are very simple in its makeup and use whilst others are very complex. For example, a spade is a machine (a simple machine), and a space shuttle is a machine too (a complex machine),   Simple Machines A simple machine is a tool, device or object with few moving parts that help us do work. Simple machines have been in use for a very long time. Early humans used simple machines to push, pull, lift, divide and crush things. They used simple machines to row rafts over water, build houses, split firewood, and carry heavy more...

Basic Electricity  Electricity Electricity exists in the smallest particle in nature called the atom. The atom is the basic building block of matter. An atom is so small that human eyes cannot see it. We only see them with the help of very powerful magnifying devices.   Illustration of an atom given below: In the atom, there are three sub-atomic particles — Protons, Neutrons and Electrons. Protons and Neutrons are located right in the nucleus (centre or core) of the atom. Around the nucleus, here are electrons that are constantly moving very quickly. The electrons move because they have some energy. Neutrons have no charges. Protons are positively charged. Electrons are negatively charged, and they encircle the nucleus. Elections encircle the nucleus because opposite charges (negative charge electrons and positive charge protons) are attracted to each other, and alike charges tend to move away from each other. The encircling electron can move from one atom to the other. When Protons and fast moving Electrons interact, electricity is produced. to simple terms, electricity is the interaction of Protons in the atom and the fast moving of Electrons around it. It is the flow of' electrons   BASIC ELECTRICITY Electricity is the flow of electrons from one place to another. Electrons can flow through any material, but does so more easily in some than in others. Since electrons are very small, as a practical matter they are usually measured in very large number. A Coulomb is                                                                    \[6.24\times {{10}^{18}}\] electrons. However, electricians are mostly intersted in electrons in motion. The flow of electons is called current, and is measueed in AMPS. One amp is equal to a flow of one coulomb per second through a wire. Making electrons flow through a resistance reqires an attractive force to pull them. This force, called Electro-Motive Force or EMF, is measured in volts. A Volt is the force required to push Amp through I Ohm of resistance. As electrons flow through a risstance, it performs a certain amount of work. It may be in the form of heat or a magnetic field or motion, but it does something. That work is called Power, and is measured in Watts. One Watt is equal to the work performed by 1 Amp pushed by 1 Volt through a resistance.   Electrical Circuit An electrical circuit is a path or line through which an electrical current flows. The path may be closed (joined at both ends), making it a loop. A closed circuit makes electrical current flow possible. It may also be an open circuit where the electron flow is cut short because the path is broken. An open circuit does not allow electrical current to flow. Below is a basic set of symbols that you may find on circuit diagrams. It is very important to know the basic more...