Electric charge in alternating current ac, on the other hand, changes direction. Powerpoint slide on alternating current compiled by akhilesh kumar. Alternating current in this video tutorial, we will understand the basic properties of alternating current ac and cover topics such as ac. As we saw with work, energy changed only when a portion of the force was in the direction of the displacement. The effective resistance is called the inductive reactance x l defined by x l 2. Ac circuits basics, impedance, resonant frequency, rl rc rlc lc circuit explained, physics problems. Cbse quick revision note for class12 physics, chemistry, maths, biology and other subject are very helpful to revise the whole syllabus during exam days. These video classes have been designed to suit the curriculum of cbse class 12 students. This document is highly rated by students and has been viewed 297 times. Alternating current, ac is generally used for power distribution, which is why the mains sockets in our homes and at work provide an alternating current to. Alternating current, ac is different to direct current.
Class 12 physics ac notes notes on alternating current. Chapter 12 alternatingcurrent circuits mit opencourseware. Read all the important points and chapterwise notes on aipmt. In this current, the charged particles move from zero to maximum value in a direction and fall to zero and goes for another cycle in the opposite. 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. Rms values since voltage and current are always changing we need some way of averaging out their effect. Alternating current ac introduction flight mechanic.
However, it is possible to convert the alternating current that is induced into the armature into a form of direct current. Introduction to alternating current ac learn electronics. For simplicity, we sill assume that phase is 0 for the rest of this tutorial. The generation of sinusoidal ac voltage can also be explained using. Basic concepts of alternating current cedengineering. Care must be taken that correct formulas are used for peak voltages and currents, average voltages and currents, rms voltages and currents. May 06, 2020 test c alternating current ac assignment class 12 notes edurev is made by best teachers of class 12. Both ac and dc describe types of current flow in a circuit. In fact, the i or rms current is the equivalent dc current that would produce the same average power loss as the alternating current. Alternating current, ac and direct current, dc are two forms of electric current that are used each with its own advantages. But the voltage phasor, 10, is perpendicular to that of the current. In this manner, as more turns are added to the coil, the same current produces larger and larger magnetic. For the case of the alternating current passing through an inductor, the same basic principles are used, but as the waveform is repetitive, we tend to look at the way the inductor responds in a slightly different way as it is more convenient.
V l i m x l, v c i m x c, v r i m r and v v m resistor v r and i are in phase. Class 12 physics revision notes for chapter 7 alternating. C is the current that changes in magnitude direction continuously with respect to time. Alternating current class 12 notes class 12 physics chapter 7 alternating current notes pdf download alternating current ac is the current generated by the vast majority of power plants and used by most power distribution systems, as it is cheaper to generate and has fewer energy losses than direct current when transmitting electricity over long distances. This document is highly rated by class 12 students and has been viewed 542 times. Download cbse class 12th revision notes for chapter 7 alternating current in pdf format for free. Alternating current class 12 notes physics mycbseguide. Direct current is a bit easier to understand than alternating current. Alternating current grade 12 physics notes khullakitab. Ac circuits composed of resistors can be analyzed using ohms law and kirchhoffs law just as we did with dc circuits.
I we see from the graph that because the values of b n are decreasing, the. Dec 24, 2019 candidates who are pursuing in class 12 are advised to revise the notes from this post. Ac circuits basics, impedance, resonant frequency, rl rc rlc lc circuit explained, physics problems duration. Introduction to basic notions on electric power 5 electric current conductor lines of force fig. Notes for alternating current circuit chapter of class 12 physics. Figure 1 current and voltage from an ac source through a simple resistor. Why, alternating current and direct current, of course. Since the current is common to all three components it is used as the horizontal reference when constructing a voltage. An alternating voltage or current is one whose magnitude changes with time and direction reverse periodically. Ohms law yields v l ix l, where v l is the rms voltage across the inductor and i is the rms in the inductor resistorinductorcapacitor circuit. Mar 05, 2019 class 12 physics notes chapter 7 alternating current. A current which flows first in one direction in a circuit, called the positive direction, then in the reverse direction or negative direction is called alternating current. Alternating current, ac and direct current, dc both have their advantages and disadvantages, but this means that there is a choice to select the best option for any given use or application.
An ac generator equipped with a device called a commutator can produce direct current. Problem 1 an alternating current i is given by i 141. Electromagnetic induction and alternating current revision notes. This document contains detailed info on fundamentals, concept and explanation of various terms and definitions required to perfect knowledge of alternating current page 1 of 1 notesgen is the no. Most students of electricity begin their study with what is known as direct current dc, which is. It is the current or voltage that in the circuit at any instant. Electric charge in alternating current ac, on the other hand, changes direction periodically. So, go ahead and check the important notes for class 12 physics alternating currents. Candidates who are pursuing in class 12 are advised to revise the notes from this post. Students will learn strong basics of electrical engineering and practical. In this video tutorial, we will understand the basic properties of alternating current ac and cover topics such as ac generator, current through ac generator, ac circuits, power factor, wattless current, and transformers.
These video classes have been designed to suit the curriculum of. Alternating current ac electrical systems are found on most multiengine, high performance turbine powered aircraft and transport category aircraft. Alternating series test we have the following test for such alternating series. This conversion of ac into dc is accomplished through the use of a commutator. In direct current dc, the electric charge current only flows in one direction. Cbse ncert notes class 12 physics alternating current. Jan 09, 2018 24 videos play all alternating current tutorials point india ltd. As the name implies, it flows first in one direction and then the other.
Basic concepts of alternating current ced engineering. With the help of notes, candidates can plan their strategy for particular weaker section of the subject and study hard. It can be represented as, the currents and voltages in a. The graph above shows the current waveform varying as a sine wave, with the current first moving in one direction and then the other. Get cbse class 12th physics key notes on alternating current. Lowpitch notes such as those produced by a tuba or bassoon consist of air molecule vibrations that are relatively slow low frequency. A transformer changes the voltage level or current level on its input winding to another value on its output winding using a magnetic field. Alternating current vs direct current as useful and as easy to understand as dc is, it is not the only kind of electricity in use. Figure 1 shows the plot of alternating voltage and alternating current as a function of time in a circuit that has only a resistor and a source of alternating current an ac generator. Rather than oscillating back and forth, dc provides a constant voltage or current. The phasor diagram representing equation 16 is shown in figure 23. The mean value of the ac is defined as equivalent steady current which when passed through a circuit would send the same amount of charge in the same time as is done by the alternating current in the same circuit in the same time. Then to summarise this transformer basics tutorial.
Class 12 physics notes chapter 7 alternating current. Resistor, inductor and capacitor all are in series. Fundamentals of alternating current 3 figure 121 sinusoidal wave values. What is the direction of the magnetic field around a vertical conductor when a the current flows upward and b the current flows downward. Notes on alternating current class 12 page 01 alternating current a. Use of a device called a rectifier that converts ac to dc. Note that your fingers point in the direction that the north pole of the compass points when it is placed in the magnetic field surrounding the wire. The direction of the lines of force is given by the law of the screwdriver. Direct current dc is used on systems that must be compatible with battery.
These notes are aligned with our channels video lectures. Dec 08, 2016 the unit of angular frequency is radsec. Lecture notes all ac circuit lectures feeg1004 studocu. Basically, what is alternating in alternating current is the polarity of the voltage source, which causes the current to flow in one direction, and then reverse, and flow in the opposite direction. Certain sources of electricity most notably, rotary electromechanical generators naturally produce voltages alternating in polarity, reversing positive and negative over time. Sep 20, 2016 may 06, 2020 test c alternating current ac assignment class 12 notes edurev is made by best teachers of class 12. Number of times this current changes its direction in one second can be defined as the frequency of the alternating current. Thats why the main difference you will see between dc and ac circuit diagrams, is that in the ac circuit diagrams, there will be no indication of.
These are the alternating current class 12 notes prepared by team of expert teachers. Ac is the same type of electricity used in industry and to power our homes. Either as a voltage switching polarity or as a current switching direction back and forth, this kind of electricity is known as alternating current ac. Download revision notes for alternating current class 12 notes and score high in exams. A transformer consists of two electrically isolated coils and operates on faradays principal of mutual induction, in which an emf is induced. The voltage and the current are out of phase by 90 o.
For this we have included pdf notes of each chapter still updating. By its very nature, an alternating waveform is changing all of the time. When placed in the vicinity of a currentcarrying conductor, the needle of a compass becomes aligned at what angle to the conductor. These notes are continuation of cbse class 12th physics notes. Apr 26, 2020 notes alternating current theory notes edurev is made by best teachers of. The current in the circuit is impeded by the back emf of the inductor coil. The revision notes covers all important formulas and concepts given in the chapter. In electrical circuits energy is dissipated only if a portion of the voltage is in phase with the current. Example 1 test the following series for convergence x1 n1 1n 1 n i we have b n 1 n. Circuit analysis of ac resistive circuits alternating. The lefthand rule for a conductor is used for what purpose q9. Test c alternating current ac assignment class 12 notes.
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