File Name: alternating voltage and current ppt to .zip
- What is Alternating Current (AC)?
- Alternating Voltage and Current
- Alternating & Direct Current: AC DC Electricity
What is Alternating Current (AC)?
Electric current is defined as the rate of flow of negative charges of the conductor. For an electric current to occur, it has to be conducted through a material. When the flow of electrons provided by electricity finds a resistance, it results in a dissipation of energy in the form of heat. If there is an excessive amount of heat generated, the tissue may be burnt. Physiologically, the difference between a normal burn and a burn caused by electricity is that electricity has the ability to burn tissue beneath the skin, even burning internal organs without apparent external evidence of it. The contact with electric current can have various effects on the human body such as pain, burns or even death.
DC is the kind of electricity made by a battery with definite positive and negative terminals , or the kind of charge generated by rubbing certain types of materials against each other. Certain sources of electricity most notably, rotary electromechanical generators naturally produce voltages alternating in polarity, reversing positive and negative over time. Whereas the familiar battery symbol is used as a generic symbol for any DC voltage source, the circle with the wavy line inside is the generic symbol for any AC voltage source. One might wonder why anyone would bother with such a thing as AC. It is true that in some cases AC holds no practical advantage over DC. In applications where electricity is used to dissipate energy in the form of heat, the polarity or direction of current is irrelevant, so long as there is enough voltage and current to the load to produce the desired heat power dissipation. However, with AC it is possible to build electric generators, motors and power distribution systems that are far more efficient than DC, and so we find AC being used predominantly across the world in high power applications.
NCBI Bookshelf. Michael R. Zemaitis ; Lisa A. Foris ; Richard A. Lopez ; Martin R.
Alternating Voltage and Current
Introduction 2. Generating AC Voltages 3. Values 6. Sinusoidal waveform are tricky things to draw. By using phasor, it can be represent as straight lines. By joining up such lines, we can undertake apparently difficult additions and subtractions and this simplifies the later analyses which will be considered.
Most of the examples dealt with so far, and particularly those utilizing batteries, have constant voltage sources. Once the current is established, it is thus also a constant. Direct current DC is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Most well-known applications, however, use a time-varying voltage source.
Alternating & Direct Current: AC DC Electricity
Both AC and DC have their own characteristics and provide different advantages that can be used in different situations. As the name implies direct current, DC is a form of electricity that flows in one direction — it is direct and this gives it its name. The characteristic of direct current, DC can be shown on a graph. Here the current can be seen to be seen to be either positive or negative only. Alternating current, AC is different to direct current.
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- С вами все в порядке. Мы уж думали, вы все погибли. Сьюзан посмотрела на него отсутствующим взглядом.
Мидж. Ответа не последовало. Бринкерхофф подошел к кабинету.