7. Upper limit of voltage on transmission line is limited by corona discharge because A. PUD operators are exposed to corona virus at very high voltages B. Ionization of air makes air act like a conductor C. Transmission lines melt at high voltage D. Electric power is converted to light 8. The synchronous speed of a 50HZ, 12 pole induction motor is А. 900 гpm В. 500 грm С. 300 грm D. 400 грm

7. Upper limit of voltage on transmission line is limited by corona discharge because A. PUD operators are exposed to corona virus at very high voltages B. Ionization of air makes air act like a conductor C. Transmission lines melt at high voltage D. Electric power is converted to light 8. The synchronous speed of a 50HZ, 12 pole induction motor is А. 900 гpm В. 500 грm С. 300 грm D. 400 грm

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

See similar textbooks

Similar questions

Subject Electrical Machines 2
! ۹:۳۳ ص 63. The rotating magnetic field cannot be obtained from a single-phase source but rather from a two-phase source. true Error Methods of starting the movement in three-phase induction motors by means of a transformer true Error An alternating current source with a frequency of 50 Hz and a maximum value of 300 amperes, and this current increases in the positive direction immediately after this moment, and that the value of the instantaneous current when time is 1/400 equals 212.1 volts true Error
THydropower Plant System The following nametag is specification of a generator in a hydropower plant. MITSUBISHI AC GENERATOR Output Voltage 4. 84.5 MVA 11 kV Current Frequency Speed Power Factor 4435 A 50 Hz 600 RPM 0.86 |Calculate the generated peak voltage. | Calculate real power of the following generator. How many pair-of-poles installed in the generator? Why does not the generator consist of one pair-of-poles only? J Why for water turbine the speed is 600 rpm not 3000 rpm such as in steam turbine? a. b. C. d. е. f. Explain why the turbine is located below the generator.
2
A three-phase synchronous generator is rated 60 MVA, 11 kV. It has an armature resistance ra = 0.1 pu and synchronous reactance xS = 1.65 pu. It is feeding into an inﬁnite bus at 11 kV delivering a current 15 kA at 0.9 power factor lagging. (a) Determine internal voltage (E) and power angle (δ). (b)Draw a vector diagram for this operation and state operating mode of the generator.(c) Infinite bus voltage falls to 10 kV while the mechanical power input to generator and itsexcitation remains unchanged. What is the value of the current, power factor and reactivepower delivered to the infinite bus.Per-unit values are given on machine rating as the base.
For the system in the diagram: 1. The line current at startup. Use this per-phase equivalent circuit:Apply Ohm's law, note that slip is equal to 1 at startup and the resulting current is complex. Show the current in polar form. 2. The starting torque. For each phase, Tstart = Pin/ധs , and the input power is the "line current squared times the equivalent rotor resistance given as 0.25/slip with slip = 1 at startup." 3. Find the full-load current with a star starter and the power factor. Use Ifl = VL/Zeq, VL from the above circuit, and Zeq must include the slip calculated in problem 4. Show the complex current in polar form 4. Determine the full-load torque. The suitable formula for the full-load torque is derived as: Tfl = (per phase x 3) Ifl2 x Req / (ധs x slip). Req is the sum of all the resistive impedances from the above circuit. Get the synchronous speed, and slip from problem 4. Note: From Problem 4: Synchronous Speed Ns = 1800 rpm Slip s = 2.5%
Please answer all subparts....
Electrical machines