Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Three-phase source voltages and phase sequence?
The elementary three-phase, two-pole generator shown in Figure has three identical stator coils (aa, bb, and cc) of one or more turns, displaced by 120° in space from each other. The rotor carries a ?eld winding excited by the dc supply through brushes and slip rings. When the rotor is driven at a constant speed, voltages of equal amplitude but different phase angle will be generated in the three phases in accordance with Faraday's law. Each of the three stator coils constitutes one phase of this single generator. If the ?eld structure is so designed that the ?ux is distributed sinusoidally over the poles, the ?ux linking any phase will vary sinusoidally with time, and sinusoidal voltages will be induced in the three phases. These three induced voltage waves will be displaced by 120 electrical degrees in time because the stator phases are displaced by 120° in space. When the rotor is driven counterclockwise, Figure (a) shows the wave forms and Figure (b) depicts the corresponding phasors of the three voltages. The time origin and the reference axis are chosen on the basis of analytical convenience. In a balanced system, all three phase voltages are equal in magnitude but differ from each other in phase by 120°. The sequence of voltages in Figure 4.1.2(b), corresponding to that of Figure (a), is known as the positive sequence (a-b-c). On the other hand, if the rotor is driven clockwise, then Figure (c) shows the corresponding phasor of the three voltages; the sequence of voltages in Figure (c) is known as negative sequence (a-c-b). Notice that in positive sequence ¯Ebb lags ¯Eaa by 120°, and ¯Ecc lags ¯Ebb by 120°; in negative sequence, however, ¯ Ecc lags ¯ Eaa by 120°, and ¯ Ebb lags ¯ Ecc by 120°.
Explain and compare forward vs. backward internalization. Forward internalization takes place when MNCs with intangible assets make FDI in order to use the assets on a larger sca
You've just won a huge $100 million lottery. You've decided to invest your winnings in the following way: $30 million in real estate, $30 million in corporate bonds and $40 mil
Suppliers and customers Suppliers as well as customers are external stakeholders with their own set of objectives profit for the supplier and possibly customer satisfaction wit
a) This refers a business, such as Palmolive-Colgate being able to sell the same product using the same marketing approach all over the world. It is used by firms with global brand
Assume we are in the midst of the financial crisis in October 2008. Your firm is considering the purchase of a 10 year put option on the S&P 500 Index. You are analyzing the pricin
Extent of Financing Required It is clear that sales are unsure with low, high and medium estimates of demand. This of itself gives a few uncertainty but the reliability and pr
Explain about the International Finance When money crosses international boundaries businesses,individualsand governments should deal with special kinds of problems. Every c
Problem: i) Assume a firm buys a new tooling machine for Rs 2000,000, installation costs net of taxes are Rs 300,000. An existing asset has a book value of Rs 400,000 and the
(a) iTraxx is a group of credit derivative index managed by the International Index Company (IIC) and covering Europe and Asia and Australia. The body in the portfolio forming th
Accounting System: The accounting systems are the primary financial systems that any business should have in place to ensure accurate and usable financial information. The b
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd