Current flow in series dc circuits 101 ir voltage drops 104 current flow in parallel dc circuits 105 magnetism 106 the magnetic field 106 temporary and permanent magnets 107 electromagnetism 107 magnetomotive force mmf 108 electromagnetic induction 109 alternating current and voltage 109 the ac sine wave 109 ac circuits 111 capacitors and. Alternating current ac circuits timevariant voltage timevarying voltage that is commercially available in large quantities and is commonly called the ac voltage. Pspice tutorial create a new project and select analog or mixed ad. These notes are continuation of cbse class 12th physics notes. The alternating current in blue has an ampere value that changes from a positive 1 to a negative 1 forming a wave with constant frequency. This portable document format \pdf\ file contains bookmarks, thumbnails, and hyperlinks to help you navigate through the document. Using an ac magnetic field simply produces about a 4volt peaktopeak sine wave at maximum current centered at 2. Like gasoline, we use it all the time, and although it is dangerous, we become complacent. One ampere is 6,280,000,000,000,000,000 electrons passing a point in one second. In order to construct a building that will last into the future, a strong foundation is a prerequisite. Boat building standards basic electricity alternating. Devices manufactured for single polarity produce a center voltage of 2. Almost all portable electronics use direct current, not alternating current.
Get cbse class 12th physics key notes on alternating current. The presence of serrations on the wheel is unnecessary and the apparatus will work with a round metal disk, usually made of copper. An alternating currentac is a current that varies sinusoidally with time. Alternating current ac, is an electric current in which the flow of electric charge periodically reverses direction, whereas in direct current dc, also dc, the flow of electric charge is only in one direction. Pictured above is a silicon controlled rectifier scr or thyrister.
To explain the details of why this is so, a bit of background knowledge about ac is necessary. Alternating current electrical impedance amplitude. Scribd is the worlds largest social reading and publishing site. This conversion of ac into dc is accomplished through the use of a commutator. Hall effect devices are made for dc, not ac as such. It can be designed to step up or step down voltages and works on the magnetic induction principle. Alternating current ac is an electric current which periodically reverses direction, in contrast to direct current dc which flows only in one direction. A timevarying current is represented by the symbol i.
The diac, or diode for alternating current, is a trigger diode that conducts current only after. Erickson department of electrical and computer engineering. What we have in our homes is installed in a way to keep us safe from harm. Both ac and dc describe types of current flow in a circuit. After reading this, you will be able to design ac ammeter using pic16f877a microcontroller. Below are the list of all electrical engineering multiple choice questions and answers for eee students. Kcl states that the total current entering a junction is equal to the total current leaving the junction. Direct current dc alternating current ac i i figure 1. Ive tried to move away from direct com interaction via interop through thirdparty packages, but when thats not an option due to cost considerations, ill use office 20072010s builtin export functionality to accomplish. The direction of the lines of force is given by the law of the screwdriver. The modules listed in the overview are linked to the corresponding pages.
Direct vs alternating current distribution systemsthat are far more ef. The zip file contains labview vis and other files which will be used in some of the experiments during the course. Alternating waveform available from commercial supplies. An ac circuit is the one in which the source of the circuit is of alternating current rather than dc direct current. Using hall effect sensors detecting alternating current. Acrobat lets you add a header and footer throughout a pdf. A new window pop up with the pspice project type, select create a blank project and click ok. Example graph of amperes over time show alternating and direct currents. Text headings in each module are linked to and f\ rom the table of contents for that module.
The term alternating indicates only that the waveform alternates between two prescribed levels in a set time. For alternating current, the current oscillates back and forth. Headers and footers can include a date, automatic page numbering, bates numbers for legal documents, or the title and author. The first edit with code is completely useless for the purpose of converting excel to pdf. In direct current dc, the electric charge current only flows in one direction. A common form of timevarying current is the sinusoidal current or alternating current ac.
Basic screen there are three windows that are opened. Current i current is the quantity of electrons passing a given point. Alternating current or ac current measurement using a pic microcontroller. Any ideal basic circuit element such as a resistor can be described mathematically in terms of its voltage and current, and in our tutorial. This approach is also employed in applications involving alternating current, including highefficiency dcac power converters inverters and power amplifiers, acac power. Electric charge in alternating current ac, on the other hand, changes direction periodically. In electrical circuits energy is dissipated only if a portion of the voltage is in phase with the current. Kirchoffs current and voltage laws kcl and kvl kirchoffs current law. Electrical current flows from a region of high charge or potential to a region of low potential. In this article, we will discuss how to measure alternating current using the current transformerct and pic microcontroller. The tutorial covers many subjects, even interfaces like usb, and has near 400 pages. Chapter 3 electric current and directcurrent circuits. It is a very important task in pic microcontroller. Physics class 12 notes of alternating current best notes from my side download the pdf below link to my notes of alternating current.
Because alternating current ac electricity is very common. You can add headers and footers to one or more pdfs. Then we will step through each of these topics in detail. The current mode works the same as voltage and resistance you have to get the correct range. Eee electrical engineering multiple choice questions. At the start of the tutorial a brief introduction of ac alternating current is provided after that a simple ac circuit is implemented in pspice and the results were analyzed precisely. The letters ac are an abbreviation for alternating current.
Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps. Such current is used in your household to run the air conditioner, refrigerator, washing machine, and other electric. Why, alternating current and direct current, of course. As we saw with work, energy changed only when a portion of the force was in the direction of the displacement. Alternating current free download as powerpoint presentation. Alternating current 12 isc 2017 investigatory project.
Squeeze the probes with a little pressure against the positive and negative terminals of the aa battery. The interaction of the current with the magnetic field of a umagnet causes the wheel to rotate. Add headers, footers, and bates numbering to pdfs, adobe. The abbreviations ac and dc are often used to mean simply alternating and direct, as when they modify current or voltage ac is the form in which electric power is delivered to. In this study, we aimed to modulate p300 amplitude using tacs by stimulating the individual ero involved in the generation of the p300 component. In particular, if a coil rotates in the presence of a magnetic field, the induced emf varies sinusoidally with time and leads to an alternating current ac, and provides a source of ac. Transcranial alternating current stimulation tacs is capable of modulating oscillatory brain activity in a frequencyspecific manner.
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