Can you help by answering this question?

With the feedback system, the transient response ...

16 views
in Synchronous machine by
A pair of synchronous machines on the same shaft may be used to generate power at 60 Hz from given source of power at 50 Hz. Using minimum number of poles for both the machines, the synchronous speed will be (a) 500 r.p.m. (b) 600 r.p.m. (c) 1000 r.p.m. (d) 1200 r.p.m. 

Your answer

Thanks for your contribution. Feel free to answer this question. Please avoid short answer. Your answer is most welcome. Be genuine.

Upload image or document:

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
Are you a robot ? (Y = Yes / N = No)
To avoid this verification in future, please log in or register.

Related questions

1 answer 16 views

In relation to the synchronous machines, which on of the following statements is false ?  (A) In salient pole machines, the direct-axis synchronous reactance is greater than the quadrature-axis synchronous reactance. (B) The damper bars help the synchronous motor self start. (C) Short circuit ratio is the ratio of ... rated armature current. (D) The V-cure of a synchronous motor represents the variation in the armature current with field excitation, at a given output power.

asked May 17, 2018 in Synchronous machine by Shimroz123
2 answers 59 views

The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

asked Dec 31, 2017 in Electrical Engineering by Quiz
0 answers 42 views

When two synchronous machines are connected in parallel the synchronizing power tends to (A) accelerate the faster machine (B) retard the faster machine (C) retards the slower machine (D) pull the faster machine out of step

asked Jun 4, 2018 in Synchronous machine by Shimroz123
0 answers 14 views

A single phase motor draws a current of 5 A from a 120 V, 60 Hz line. The power factor of the motor is 65%. Calculate the active power absorbed by the motor.  (A) 600 W (B) 390 W (C) 456 W (D) 650 W 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 88 views

A single phase 60 Hz generator supplies an inductive load of 4500kW at a power factor of 0.80 lagging by means of a 20 km long overhead transmission line. The line resistance and inductance are 0.0195 ohm and 0.60 mH per km. The voltage at the receiving end is required to be kept constant at 10.2 kV. Find the voltage regulation of the line.  (A) 12.59% (B) 16.34% (C) 32.68% (D) 41.15% 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 12 views

If transformer frequency is changed from 60 Hz, to 60 Hz the ratio of eddy current loss 60 Hz to 50 Hz, at constant voltage will be?

asked Mar 27, 2018 in Power system by Shimroz123
1 answer 34 views

An 8 pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 r.p.m. by a prime mover in the opposite direction of revolving magnetic field. The frequency of the rotor current is (a) 30 Hz (b) 60 Hz (c) 120 Hz (d) 180 Hz 

asked May 25, 2018 in Induction Machine by Shimroz123
0 answers 21 views

The active power of a synchronous generator can be varied mainly by (a) changing field excitation (b) changing of prime mover speed (c) both (a) and (b) (d) none of the above

asked May 25, 2018 in Synchronous machine by Shimroz123
1 answer 29 views

The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be (A) 3.6 V. (B) 2.5 V. (C) 3.0 V. (D) 6.0 V.

asked May 22, 2018 in Transformer by Shimroz123
1 answer 25 views

The primary winding of a 220/6 V, 50 Hz transformer is energised from 110 V, 60 Hz supply. The secondary output voltage will be; (A) 3.6 (B) 2.5 V (C) 3.0 V (D) 6.0 V

asked Apr 9, 2018 in Electrical Engineering by Shimroz123
1 answer 18 views

A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is  (A) magnetizing (B) demagnetizing (C) cross-magnetizing (D) ineffective

asked May 17, 2018 in Synchronous machine by Shimroz123
1 answer 46 views

A 100 MVA, 11 KV, 3-phase, 50 Hz, 8—pole synchronous generator has an inertia constant H equal to 4 seconds. The stored energy in the rotor of the generator at synchronous speed will be  A) 100 MJ B) 400 MJ C) 800 MJ D) 12.5 MJ

asked May 20, 2018 in Synchronous machine by Shimroz123
1 answer 24 views

If we change the excitation of synchronous machine will it affect on power factor?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 23 views

If the field of synchronous motor is under excited, power factor will be?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 35 views

The corona loss in a 50 Hz system is 0.25 kW/ph/km. At a frequency of 60 Hz, the corona loss would be   (a) 0.30 kW/ph/km (b) 0.36 kW/ph/km (c) 028 kW/ph/km (d) 0.21 kW/ph/km

asked May 13, 2018 in Power system by Shimroz123
1 answer 24 views

A cylindrical rotor synchronous motor is switched on to the supply with its field windings shorted on themselves, the motor will .  A) Not start B) Start but will not run at synchronous speed C) Start as an induction motor and then run as a synchronous motor D) Start and run as a synchronous motor

asked May 20, 2018 in Synchronous machine by Shimroz123
1 answer 27 views

A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?

asked Mar 20, 2018 in Synchronous machine by Shimroz123
1 answer 29 views

The synchronous motor which works on leading power factor and does not drive any mechanical load is called?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 41 views

How can a magnetic field be used to generate an electric current?

asked Mar 10, 2018 in Engineering electromagnetic by Quiz
0 answers 22 views

A three phase transformer can be used in emergency at reduced rating of 58% to deliver three phase power when it is connected (a) in star-delta (b) delta-star (c) star-star (d) delta-delta

asked Apr 14, 2018 in Electrical Engineering by Shimroz123
1 answer 15 views

A three phase, salient pole synchronous motor is connected to an infinite bus. It is operated at no load a normal excitation. The field excitation of the motor is first reduced to zero and then increased in reverse direction gradually. Then the armature current.  (A) Increases continuously (B) First increases and then decreases steeply (C) First decreases and then increases steeply (D) Remains constant

asked May 17, 2018 in Synchronous machine by Shimroz123
0 answers 109 views

A single phase transformer rated at 3000 kVA, 69 kV 4.16 kV, 60 Hz has a total internal impedance Zp of 127 ohm, referred to the primary side. Calculate the primary current if the secondary is accidentally short circuited.  (A) 43.5 A (B) 543 A (C) 9006 A (D) 721 A 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 15 views

In a half-wave rectifier, if an a.c supply is 60 Hz. Then what is the a.c ripple at output? (A) 30 Hz (B) 60 Hz (C) 20 Hz (D) 15 Hz

asked Apr 26, 2018 in Electronics Engineering by Shimroz123
1 answer 18 views

What is the slip (as a percentage) when a 6 pole single phase induction motor operating on 220 V and 60 Hz is rotating at speed of 1140 rpm? A) 60% B) 5% C) 10% D) None of these

asked Apr 29, 2018 in Electrical Engineering by Shimroz123
1 answer 32 views

A 60 Hz, 320 km lossless line has Bending end voltage 1.0 p.u, The receiving end voltage on no load is?

asked Mar 27, 2018 in Power system by Shimroz123
1 answer 26 views

A 500 MW, 3-phase, Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 p.f. The line current when operating at full load rated conditions will be  (A) 13.43 kA (B) 15.79 kA (C) 23.25 kA (D) 27.36 kA

asked May 17, 2018 in Synchronous machine by Shimroz123
1 answer 30 views

For a fault at the terminals of a synchronous generator, the fault current is maximum for a  A) 3-phase fault B) 3-phase to ground fault C) Line to ground fault D) Line to line fault

asked May 17, 2018 in Synchronous machine by Shimroz123
0 answers 38 views

The maximum torque which a synchronous motor will develop at rest for any angular position of the rotor, at rated stator supply voltage and frequency, is known as?

asked Mar 20, 2018 in Synchronous machine by Shimroz123
0 answers 30 views

A coil having 90 turns is connected to a 120 V, 60 Hz source. If the effective value of the magnetizing current is 4 A. Calculate the inductance of the coil.  (A) 79.6 mH (B) 121.2 mH (C) 32.2 mH (D) 83.16 mH

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 30 views

The power factor of a synchronous machine is controlled by (A) connected load (B) generated voltage (C) field current (D) load angle 

asked Jun 4, 2018 in Synchronous machine by Shimroz123
0 answers 16 views

A series RLC circuit resonate at 200 Hz. If the capacitance is increased to four times, the circuit will be in resonance at   (a) 100 Hz (b) 200 Hz (c) 400 Hz (d) 800 Hz  

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 17 views

The damping winding in synchronous motor is generally used to?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 40 views

A 60 Hz, 2 pole alternator should run at • a. 3000 r.p.m. c. 1500 r.p.m. • b. 3600 r.p.m. d. 1800 r.p.m.

asked May 14, 2018 in Alternator by Shimroz123
0 answers 31 views

A salient pole synchronous motor is running at no load. Its field current is switched off, the motor will (a) come to stop. (b) continue to run at synch. speed. (c) continue to run at a speed slightly less than synch. speed. (d) continue to run at a speed slightly more than the synch. speed. 

asked May 25, 2018 in Synchronous machine by Shimroz123
0 answers 17 views

A 3 Phase, 60 Hz generator connected in Y connection, generates a line to line voltage of 23900 V. Calculate the peak line voltage.  (A) 13800 V (B) 33800 V (C) 42300 V (D) 23900 V 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 27 views

A 12 -pole, 440 V, 50 Hz, 3 -phase synchronous motor takes a line current of 100 A at 0.8 pf leading. Neglecting losses, the torque developed will be

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 63 views

What type of excitation is given to the rotor winding of a synchronous motor?  (A) DC supply at 100 -250 V (B) AC supply at 400 V (C) Revolving field (D) Induction from stator currents 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 18 views

If we change the excitation of synchronous machine will it affect on motor speed?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 19 views

The back emf of synchronous motor depends on?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
1 answer 13 views

Hunting in synchronous motor cannot be due to?

asked Mar 18, 2018 in Synchronous machine by Shimroz123
2 answers 74 views

The maximum power in a synchronous motor (for a given excitation) is produced when the power angle is equal to: (A) 0° (B) 45° (C) 60° (D) 90°

asked Apr 11, 2018 in Computer Engineering by Shimroz123
1 answer 14 views

Whether a given point in the S-plane lies on the Root Locus of a system can be determined by (A) Magnitude criterion (B) Angle Criterion (C) Both Magnitude and Angle Criteria (D) Break-in and Break-away Criteria

asked Apr 25, 2018 in Control System by Shimroz123
0 answers 12 views

During 3-phase short circuit on a unloaded alternator, the dc component may be zero in (1) One phase only (2) Any two phases (3) All three phases (4) None of the above 

asked Apr 11, 2018 in Electrical Engineering by Shimroz123

Welcome to electronics2electrical.com here you can ask questions related to electrical, electronics, mechanical, telecommunication, instrumentation, computer, mathematics, physics etc.
Be respectful to all the members. Do not copy and paste the answers from other websites which have copyright content. While asking question give full details about it.

Categories

Most popular tags

power motor dc circuit transformer voltage current used system phase resistance factor synchronous load ac energy induction electric generator series frequency between speed capacitor use electrical meter line difference control type mosfet transmission magnetic plant high single instrument bjt unit source advantages function diode and machine winding field define torque parallel amplifier supply shunt thyristor motors electricity arduino maximum time relay armature problem value on transformers types coil diagram state flow ratio material three formula starting direction theorem method emf operating efficiency digital wave microprocessor test instruments inductance loss measure operation connected signal low applications effect single-phase network temperature working constant losses different law wattmeter measuring compare controlled breaker drive device logic rc full switch flux wire resistivity disadvantages free of materials machines angle force converter conductor transistor gain open protection scr core measurement number bridge principle generators reactance circuits negative the friction iron loop short pole battery conservation steam resistors hysteresis computer using analog lines secondary station gate a rectifier inverter linear induced relays nuclear capacitance basic characteristics design direct work rotor electronics ammeter forces diesel damping rlc connection factors capacitors minimum insulation moving regulation running self systems air fault range main stability quality starter igbt eddy alternator ideal rl average 3-phase plants arc thermal error fuzzy biasing dielectric pressure balanced superposition errors copper rotation feedback impedance measured electronic electrons charge inductive transfer explain start off back curve over solar is three-phase tariff locomotive peak bias zener engineering commutator surge conductors rating universal potentiometer density permanent mechanical transducer capacity memory adc excitation two fuse pure harmonics application semiconductor inductor internal pmmc reaction welding resonance traction permeability breakers rms designed electromagnetic si generation brushes switching capacitive shaded rate 1 distribution resistor methods delta star oscillator reluctance simplification algebra 8085 boolean weston dynamometer insulating strength installation definition fuel heating earth units

8,514 questions

7,113 answers

135 comments

3,090 users

...