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°.
Define the balance of payments. Answer: The balance of payments that is abbreviated as BOP can be defined as the statistical record of a country’s international transactions ove
Illustrate the comparison between equity and debt Equity and Debt: A Comparison 1. Equity shares don't carry any fixed charges on them. If company doesn't generate positiv
evaluate the importance of leverage in financial management of a small scale company
Public Provident Fund (ppf) The Public Provident Fund (PPF) scheme was started in 1968-69 with the aim to provide a financial instrument to workers in the unorganized sector to
Q. Explain Net Present Value Method? Net Present Value (NPV) Method: - This process measures the Present value of returns per rupee invested. In this method present value of
Q. Describe Historical cost and future costs? Historical cost and future costs: another problem in the determine of cost of the capital arise on the accounts of the difference
discuss the applicability
Define country risk. How is it different from political risk? Country risk is a broader quantify of risk as compared to the political risk, as the former encompasses political ri
Ask queswtion #Minimum 100 words accepted# what are the characteristics of debt finance? What are the similarities and differences between debt finance and ordinary share capital
your firm is considering its household products division. you identify John Lewis as a firm with comparable investments. suppose J.L. equity has a market capitalization of 150 bill
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