Consider the following statements regarding capability curves of a synchronous generator :

Consider the following statements regarding capability curves of a synchronous generator : 

1. The MVA loading should not exceed the generator rating. 

2. The field current should not be allowed to exceed a specified value determined by field heating. 

3. The MW loading should not exceed the rating of the prime mover. 

4. The load angle must be more than 90°. 

Which of the above statements are correct ?
by

1 Answer

Answer :

Consider the following statements regarding capability curves of a synchronous generator : 

1. The MVA loading should not exceed the generator rating. 

2. The field current should not be allowed to exceed a specified value determined by field heating. 

3. The MW loading should not exceed the rating of the prime mover. 

4. The load angle must be more than 90°. 

Which of the above statements are correct ?


1, 2 and 3 only

by

Related questions

What are V and inverted V curves of synchronous motor ?

Description : What are V and inverted V curves of synchronous motor ?

Last Answer : The variation of magnitude of line current with respect to the field current is called V curve . The variation of power factor with respect to the field current is called inverted V curve.

Draw and explain V and inverted V curves for synchronous motor.

Description : Draw and explain V and inverted V curves for synchronous motor.

Last Answer : V curves' and inverted V curves' for Synchronous Motor:  V curve:  V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted ... Vcurves of synchronous motor. The highest point on each of these curves indicates unity power factor.

Consider the following statements: 1. A grid connected induction generator always supplies

Description : Consider the following statements:  1. A grid connected induction generator always supplies leading reactive power to the bus  2. An overexcited synchronous motor draws current at a lagging power factor  3. An underexcited synchronous ... (c) 1, 3 and 4 are correct (d) 1, 2, 3 and 4 are correct 

Last Answer : Consider the following statements:  1. A grid connected induction generator always supplies leading reactive power to the bus  2. An overexcited synchronous motor draws current at a lagging power factor  3. An underexcited ... correct (c) 1, 3 and 4 are correct (d) 1, 2, 3 and 4 are correct 

Why Generator should run within capability region?

Description : Why Generator should run within capability region?

Last Answer : Operating the Generator in excess of the capability curves will causes increase in copper temperature, thermal expansion and higher insulation stresses. 

Consider the following statements regarding corona : 1. It causes radio interference. 2. It attenuates lightning...

Description : Consider the following statements regarding corona :  1. It causes radio interference.  2. It attenuates lightning surges.  3. It causes power loss.  4. It is more prevalent in the middle conductor of a transmission line employing ... only (b) 1, 2 and 4 only (c) 1, 2, 3 and 4 (d) 3 and 4 only

Last Answer : Consider the following statements regarding corona :  1. It causes radio interference.  2. It attenuates lightning surges.  3. It causes power loss.  4. It is more prevalent in the middle conductor of a transmission ... 3 only (b) 1, 2 and 4 only (c) 1, 2, 3 and 4 (d) 3 and 4 only

Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections

Description : Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections :  1. Being a temporary remedy when one transformer forms of Delta -Delta system is &imaged, and removed from service.  ... and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

Last Answer : Consider the following statements regarding three-phase transformers in Open -Delta (V -V) connections :  1. Being a temporary remedy when one transformer forms of Delta -Delta system is &imaged, and removed from service.  ... and 2 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

Consider the following statements regarding Peer -to -Peer computing environment : 1. In this system,...

Description : Consider the following statements regarding Peer -to -Peer computing environment :  1. In this system, clients and servers are not distinguished from one another.  2. All nodes distributed throughout the ... just a replica of the file -server system.  Which of the above statements are correct ?

Last Answer : Consider the following statements regarding Peer -to -Peer computing environment :  1. In this system, clients and servers are not distinguished from one another.  2. All nodes distributed throughout the system ( ... .  Which of the above statements are correct ? 1, 2 and 3 only

A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of...

Description : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is (A) 2/15 p.u. (B) 5/6 p.u. (C) 1.0 p.u. (D) 1.2 p.u.

Last Answer : A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is 5/6 p.u.

A synchronous generator is feeding power to infinite bus bars at unity power factor. Its excitation is now...

Description : A synchronous generator is feeding power to infinite bus bars at unity power factor. Its excitation is now increased. It will feed (a) The same power but at a leading power factor (b) The same power ... a lagging power factor (c) More power at unity power factor (d) Less power at unity power factor

Last Answer : A synchronous generator is feeding power to infinite bus bars at unity power factor. Its excitation is now increased. It will feed The same power but at a lagging power factor 

Consider the following statements regarding the network shown in the figure. The eqivalent resistance of the network between points A and B is indepen

Description : Consider the following statements regarding the network shown in the figure. The eqivalent resistance of the network between points A and B is indepen

Last Answer : Consider the following statements regarding the network shown in the figure. The eqivalent resistance of the network between ... D. (1), (2) and (3)

Consider the following statements regarding Andaman and Nicobar Islands: 1. It enjoys equatorial climate 2. This is the only place in India where a volcano is located 3. This is the only place in India where coral bed is found Which of the statements given above is/are correct? [NDA 2010] (a) 1, 2 and 3 (b) 1 and 2 (c) 2 and 3 (d) 1 only

Description : Consider the following statements regarding Andaman and Nicobar Islands: 1. It enjoys equatorial climate 2. This is the only place in India where a volcano is located 3. This is the only place in India where coral bed is found Which of the ... 2010] (a) 1, 2 and 3 (b) 1 and 2 (c) 2 and 3 (d) 1 only

Last Answer : Ans: (b)

Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return. B. As long as you are not dealing with mutually exclusive projects, capital rationing, or unusual projects having multiple sign changes in the cash-flow stream, the internal rate of return method can be used with reasonable confidence. C. The internal rate of return does not consider the time value of money. D. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculated

Description : Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return. B. As long as you are not dealing with ... of return is rarely used by firms today because of the ease at which net present value is calculated

Last Answer : D. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculated.

Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return. B. As long as you are not dealing with mutually exclusive projects, capital rationing, or unusual projects having multiple sign changes in the cash-flow stream, the internal rate of return method can be used with reasonable confidence. C. The internal rate of return does not consider the time value of money. D. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculated.

Description : Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return. B. As long as you are not dealing with ... of return is rarely used by firms today because of the ease at which net present value is calculated.

Last Answer : D. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculated.

Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return B. As long as you are not dealing with mutually exclusive projects, capital rationing, or unusual projects having multiple sigD. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculatedn changes in the cash-flow stream, the internal rate of return method can be used with reasonable confidence. C. The internal rate of return does not consider the time value of money.

Description : Which of the following statements is correct regarding the internal rate of return (IRR) method? A. Each project has a unique internal rate of return B. As long as you are not dealing with ... of return is rarely used by firms today because of the ease at which net present value is calculated

Last Answer : D. The internal rate of return is rarely used by firms today because of the ease at which net present value is calculated.

Consider the following statements regarding the satellite imaging: 1. The satellite orbit is fixed in the inertial space 2. During successive across-track imaging, the earth rotates beneath the sensor 3. The satellite images a skewed area Which one of the following statements is/are correct? (A) 1, 2, 3 (B) 1, 3 (C) 2, 3 (D) 1, 2

Description : Consider the following statements regarding the satellite imaging: 1. The satellite orbit is fixed in the inertial space 2. During successive across-track imaging, the earth rotates beneath the sensor 3. The satellite images a skewed area ... ? (A) 1, 2, 3 (B) 1, 3 (C) 2, 3 (D) 1, 2

Last Answer : Answer: Option A

Consider the following statements regarding Coulomb’s theory of earth pressure: 1. It is based on wedge theory of earth pressure. 2. It assumes the wall surface to be rough. 3. It may or may not satisfy the static equilibrium condition occurring in nature. Which of these statements are correct? (a) 1, 2 & 3 (b) 1 & 2 only (c) 2 & 3 only (d) 1 & 3 only

Description : Consider the following statements regarding Coulomb's theory of earth pressure: 1. It is based on wedge theory of earth pressure. 2. It assumes the wall surface to be rough. 3. It may or may not satisfy the static equilibrium condition ... 1, 2 & 3 (b) 1 & 2 only (c) 2 & 3 only (d) 1 & 3 only

Last Answer : (b) 1 & 2 only

Consider the following statements regarding the formation of P-N junctions: 1. Holes diffuse across the junction from P-side to N—side 2. The depletion layer is wiped out. 3. There is continuous flow of current across the junction 4. A barrier potential is set up across the junction Which of the above statements are correct? (a) 1 and 3 (b) 2 and 3 (c) 1 and 4 (d) 2 and 4

Description : Consider the following statements regarding the formation of P-N junctions: 1. Holes diffuse across the junction from P-side to N-side 2. The depletion layer is wiped out. 3. There is continuous flow of current across the junction 4 ... correct? (a) 1 and 3 (b) 2 and 3 (c) 1 and 4 (d) 2 and 4

Last Answer : Ans: (c) When a pn-junction is formed, there will be diffusion of carries across the junctions followed by recombination, and the creation of a depletion layer across which a ... potential is established, which will prevent further diffusion of carries across the junction, leading to equilibrium

What are magnetic field lines? Justify the following statements (a) Two magnetic field lines never intersect each other. (b) Magnetic field lines are closed curves. -Science

Description : What are magnetic field lines? Justify the following statements (a) Two magnetic field lines never intersect each other. (b) Magnetic field lines are closed curves. -Science

Last Answer : Magnetic field lines: It is defined as the path along which the unit North pole (imaginary) tends to move in a magnetic field if free to do so. (a) The magnetic lines of force do not intersect ( ... a bar magnet and converge its south pole. Inside the magnet they move from south pole to north pole.

Which of the following statements is correct concerning the motor performance curves and data table shown in the illustration? EL-0006 A. The motor RPM at full load is 1737 RPM. B. The motor draws 12.62 kw from the switchboard when operating at full load. C. If the motor was developing 10 HP its power factor would be 0.92. D. All of the above.

Description : Which of the following statements is correct concerning the motor performance curves and data table shown in the illustration? EL-0006 A. The motor RPM at full load is 1737 RPM. B. The motor draws 12.62 kw ... If the motor was developing 10 HP its power factor would be 0.92. D. All of the above.

Last Answer : Answer: D

The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip increases, rotor reactance decreases. B. The pullout point on the torque curve is about seven times the normal full load torque value. C. At stand still, stator current is 150% of normal. D. If the motor is loaded to the point where 40% slip has resulted, it will stall.

Description : The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip ... D. If the motor is loaded to the point where 40% slip has resulted, it will stall.

Last Answer : Answer: D

Alternator Synchronous Generator To say Is Why ?

Last Answer : alternator Synchronous At speed Rotate Is Says This one Synchronous Generator Says.

Induction generator a) can not work in isolation b) can work in isolation c) should work in parallel with synchronous generators d) any of the mentioned

Description : Induction generator a) can not work in isolation b) can work in isolation c) should work in parallel with synchronous generators d) any of the mentioned

Last Answer : Ans: C

If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ahead or behind its normal position as it rotates. This co A. hunting B. direct coupling C. peaking D. harmonic coupling

Description : If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ahead or behind ... as it rotates. This co A. hunting B. direct coupling C. peaking D. harmonic coupling

Last Answer : Answer: A

The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Description : The direction of propeller shaft rotation in a turbo-electric synchronous propulsion drive motor is changed by reversing the _____________. A. polarity of the propulsion motor B. polarity of the propulsion generator C. phase sequence of power to the motor D. phase sequence of power to the generator

Last Answer : Answer: C

The propeller shaft speed in a turbo-electric, synchronous, propulsion drive motor is changed by varying the __________. A. turbine speed B. number of motor poles C. field strength of the generator D. field strength of the motor

Description : The propeller shaft speed in a turbo-electric, synchronous, propulsion drive motor is changed by varying the __________. A. turbine speed B. number of motor poles C. field strength of the generator D. field strength of the motor

Last Answer : Answer: A

If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ahead or behind its normal position as it rotates. This hu A. amortisseur windings B. direct coupling C. increase governor speed droop D. decreasing governor speed droop

Description : If the driving torque, such as that produced by a diesel engine, creates pulsations when coupled with a synchronous generator operating in parallel; the generator rotor may be periodically pulled ... windings B. direct coupling C. increase governor speed droop D. decreasing governor speed droop

Last Answer : Answer: A

The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply

Description : The most common source of excitation for synchronous motors is a/an _____________. A. low voltage battery B. motor attenuator set C. DC exciter generator D. AC supply

Last Answer : Answer: C

In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength

Description : In an AC synchronous motor electric propulsion plant, propeller speed is controlled by varying the _____________. A. prime mover speed B. electric coupling field strength C. number of energized main motor poles D. propulsion generator field strength

Last Answer : Answer: A

What is the difference between synchronous generator & asynchronous generator?

Description : What is the difference between synchronous generator & asynchronous generator?

Last Answer : In simple, synchronous generator supply’s both active and reactive power but asynchronous generator (induction generator) supply’s only active power and observes reactive power for magnetizing. This type of generators is used in windmills.

What Is The Difference Between Synchronous Generator & Asynchronous Generator?

Description : What Is The Difference Between Synchronous Generator & Asynchronous Generator?

Last Answer : In simple, synchronous generator supply’s both active and reactive power but asynchronous generator(induction generator) supply’s only active power and observe reactive power for magnetizing. This type of generators are used in windmills.

Why Alternator is called Synchronous generator?

Description : Why Alternator is called Synchronous generator?

Last Answer : Because it rotates at a constant (i.e.synchronous speed ) no matter what the load on alternator is.For instance if its a 2 pole machine it will rotate at 3000 rpm to produce a frequency of 50 Hz in India.

What is the difference between synchronous generator and asynchronous generator?

Description : What is the difference between synchronous generator and asynchronous generator?

Last Answer :  In simple, synchronous generator supplies’ both active and reactive power but asynchronous generator (induction generator) supply’s only active power and observe reactive power for magnetizing. This type of generators is used in windmills.

77. type of generator are made use in wind turbines. a) Recreational generators b) Synchronous generator c) Asynchronous generator d) Alternator

Description : 77. type of generator are made use in wind turbines. a) Recreational generators b) Synchronous generator c) Asynchronous generator d) Alternator

Last Answer : Asynchronous generator

A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Description : A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Last Answer : (a) series wound generator

A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Description : A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above

Last Answer : (a) series wound generator

The active power of a synchronous generator can be varied mainly by

Description : 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

Last Answer : C

A hydraulic turbine having rated speed of 250 rpm is connected to a synchronous generator. In order to

Description : A hydraulic turbine having rated speed of 250 rpm is connected to a synchronous generator. In order to produce power at 50 Hz, the number of poles required in the generator are (A) 6 (B) 12 (C) 16 (D) 24

Last Answer : A hydraulic turbine having rated speed of 250 rpm is connected to a synchronous generator. In order to produce power at 50 Hz, the number of poles required in the generator are 24

A 100 MVA, 11 KV, 3-phase, 50 Hz, 8—pole synchronous generator has an inertia constant H equal to

Description : 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

Last Answer : 800

A stand alone engine driven synchronous generator is feeding a partly inductive load. A capacitor is now

Description : A stand alone engine driven synchronous generator is feeding a partly inductive load. A capacitor is now connected across the load to completely nullify the inductive current. For this operating condition.  ... left unaltered (D) the field current has to be reduced and fuel input left unaltered

Last Answer : A stand alone engine driven synchronous generator is feeding a partly inductive load. A capacitor is now connected across the load to completely nullify the inductive current. For this operating condition.  the field current has to be reduced and fuel input left unaltered

A 500 MW, 3-phase, Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 p.f. The line

Description : 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

Last Answer : 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 15.79 kA

A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction

Description : 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

Last Answer : A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is demagnetizing 

The angle δ in the swing equation of a synchronous generator is the

Description : The angle δ in the swing equation of a synchronous generator is the  (A) angle between stator voltage and current (B) angular displacement of the rotor with respect to the stator (C) angular ... (D) angular displacement of an axis fixed to the rotor with respect to a synchronously rotating axis

Last Answer : The angle δ in the swing equation of a synchronous generator is the angular displacement of an axis fixed to the rotor with respect to a synchronously rotating axis

For a fault at the terminals of a synchronous generator, the fault current is maximum for a

Description : 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

Last Answer : C) Line to ground fault

A 500 MVA, 11 KV synchronous generator has 0.2 p.u. synchronous reactance. The p.u. synchronous reactance

Description : A 500 MVA, 11 KV synchronous generator has 0.2 p.u. synchronous reactance. The p.u. synchronous reactance on the base values of 100 MVA and 22 KV is  A) 0.16 B) 0.01 C) 4.0 D) 0.25

Last Answer : A 500 MVA, 11 KV synchronous generator has 0.2 p.u. synchronous reactance. The p.u. synchronous reactance on the base values of 100 MVA and 22 KV is 0.01

In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load

Description : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load  (A) The armature current increases and the power factor decreases  (B) The armature ... but is lagging  (D) The armature current decreases and the power factor increases and is leading

Last Answer : In a synchronous generator if the excitation increased from a low value to normal value, with a fixed load The armature current decreases and the power factor increases and is leading

In a synchronous generator delivering lagging power factor load

Description : In a synchronous generator delivering lagging power factor load  (1) the excitation emf leads terminal voltage by the power angle (2) the excitation emf lags terminal voltage by the power angle (3) ... by the power factor angle (4) excitation emf lags the terminal voltage by the power factor angle

Last Answer : In a synchronous generator delivering lagging power factor load the excitation emf leads terminal voltage by the power angle

The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu

Description : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are 0.866 pu, 0.5 pu

The armature reaction in a synchronous generator supplying leading power factor load is

Description : The armature reaction in a synchronous generator supplying leading power factor load is (A) magnetizing (B) demagnetizing (C) demagnetizing and cross-magnetizing (D) magnetizing and cross-magnetizing

Last Answer : The armature reaction in a synchronous generator supplying leading power factor load is magnetizing and cross-magnetizing