When TG works as induction generator?

When TG works as induction generator?
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1 Answer

Answer :

When excitation alone lost.  
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Related questions

Why motoring should be prevented in TG and DG?

Description : Why motoring should be prevented in TG and DG? 

Last Answer : In TG motoring prevented due to the turbine limitation otherwise last stage blade will fails. In DG motoring prevented, because of unburned fuel catches fire in DG. 

What is the % overload allowed for TG and DG?

Description : What is the % overload allowed for TG and DG?

Last Answer : For TG nil For DG 110% for 2 hours. 

What are the materials used for TG rotor and blades?

Description : What are the materials used for TG rotor and blades?

Last Answer : TG rotor is made up of alloy steel and blades are made up of stainless steel.  

A transformer works on the principle of – (1) Self induction (2) Mutual induction (3) Generator (4) Inverter

Description : A transformer works on the principle of – (1) Self induction (2) Mutual induction (3) Generator (4) Inverter

Last Answer : (2) Mutual induction

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Induction generator is self excited machine. a) True b) False

Description : Induction generator is self excited machine. a) True b) False

Last Answer : Ans: B

Voltage build up in an isolated induction generator depends on A. Capacitor bank value B. Residual magnetism of the rotor iron C. Residual magnetism of the stator iron a) A, B b) A, B, C c) B d) A, C

Description : Voltage build up in an isolated induction generator depends on A. Capacitor bank value B. Residual magnetism of the rotor iron C. Residual magnetism of the stator iron a) A, B b) A, B, C c) B d) A, C

Last Answer : Ans: A

If the residual flux is absent in the rotor iron of the isolated induction generator, a) it will not run. b) it will run as induction motor c) it will burn the winding d) it will not affect the characteristic of the generator

Description : If the residual flux is absent in the rotor iron of the isolated induction generator, a) it will not run. b) it will run as induction motor c) it will burn the winding d) it will not affect the characteristic of the generator

Last Answer : Ans: A

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

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Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full speed. C. The motor will run as a generator with the proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Description : Which statement is true concerning a split-phase induction motor? A. Motor rotation can be reversed without changing the windings or leads. B. Motor speed can be readily adjusted from zero to full ... proper wiring. D. Motor rotation can be reversed by reversing the leads on the starting winding.

Last Answer : Answer: D

A transformer works on the basic principle of ____________. A. self impedance B. attraction and repulsion C. mutual induction D. increasing power

Description : A transformer works on the basic principle of ____________. A. self impedance B. attraction and repulsion C. mutual induction D. increasing power

Last Answer : Answer: C

How generator earth fault relay works?

Description : How generator earth fault relay works? 

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What are the works to be done in generator in major overhauling?

Description : What are the works to be done in generator in major overhauling?

Last Answer : Works on stator a) Hydro test (DM water at 5 kg/cm2 pressure, leak acceptable is 5% for 24 hrs). b) Hydro test of H2 coolers (DM water at 4 kg/cm2 for 30 seconds no leak is allowed) ... . j) Slip-ring groove cutting and machining. k) Patina formation. Then OCC test. 

The lipoprotein with the fastest electrophoretic mobility and lowest TG content are (A) VLDL (B) LDL (C) HDL (D) Chylomicrones

Description : The lipoprotein with the fastest electrophoretic mobility and lowest TG content are (A) VLDL (B) LDL (C) HDL (D) Chylomicrones

Last Answer : Answer : C

.If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, then which of the following will result? (a) CAT GAT GAT G (b) A non-sense mutation (c) C ATG ATG ATG (d) CA TGA TGA TG

Description : .If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, then which of the following will result? (a) CAT GAT GAT G (b) A non-sense mutation (c) C ATG ATG ATG (d) CA TGA TGA TG

Last Answer : (a) CAT GAT GAT G

.If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, then which of the following will result? (a) CAT GAT GAT G (b) A non-sense mutation (c) C ATG ATG ATG (d) CA TGA TGA TG

Description : .If the DNA codons are ATG ATG ATG and a cytosine base is inserted at the beginning, then which of the following will result? (a) CAT GAT GAT G (b) A non-sense mutation (c) C ATG ATG ATG (d) CA TGA TGA TG

Last Answer : (a) CAT GAT GAT G

Shear modulus G is given by (a) G = t/g (b) G = g/t (c) G = Tg/t (d) G = T/g

Description : Shear modulus G is given by (a) G = t/g (b) G = g/t (c) G = Tg/t (d) G = T/g

Last Answer : (a) G = t/g

Angle of twist of a circular shaft is given by a. GJ/Tl b. Tl/GJ. c. TJ/Gl. d.TG/Jl.

Description : Angle of twist of a circular shaft is given by a. GJ/Tl b. Tl/GJ. c. TJ/Gl. d.TG/Jl.

Last Answer : b. Tl/GJ.

Specific drug therapy to lower serum triglycerides (TG) in a subject with normal LDL-cholesterol level is indicated: A. In all subjects with serum TG> 150 mg/dl B. In subjects with existing coronary artery disease and serum TG > 150 mg/dl C. In subjects with HDL-cholesterol < 40 mg/dl and serum TG > 150 mg/dl D. Both 'B' and 'C' are correct

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Last Answer : D. Both 'B' and 'C' are correct

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The principle of AC generator is: a. Mutual induction b. self induction c. electromagnetic induction d. Induction

Description : The principle of AC generator is: a. Mutual induction b. self induction c. electromagnetic induction d. Induction

Last Answer : b. self induction

Which one of the following laws best describes the operation of an electric generator? w) Ampere's Law x) Gauss' Law y) Ohm's Law for Conductors z) Faraday's Law of Induction

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Last Answer : ANSWER: Z -- FARADAY'S LAW OF INDUCTION 

With a neat diagram explain doubly fed induction generator (DFIG).

Description : With a neat diagram explain doubly fed induction generator (DFIG). 

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Explain Squirrel Cage Induction Generator (SCIG) and also draw a diagram.

Description : Explain Squirrel Cage Induction Generator (SCIG) and also draw a diagram. 

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Description : Induction generator is stable at a: 

Last Answer : Induction generator is stable at a: speed above synchronous speed

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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 

can induction motor be used as generator?

Last Answer : if induction motor rotates exceed than its synchronous speed, it acts as a generator.

Which common devices works on the basis of the principle of mutual induction? -Do You Know?

Description : Which common devices works on the basis of the principle of mutual induction? -Do You Know?

Last Answer : answer:

Which common devices works on the basis of the principle of mutual induction?

Description : Which common devices works on the basis of the principle of mutual induction?

Last Answer : – Transformer

Which common devices works on the basis of the principle of mutual induction?

Description : Which common devices works on the basis of the principle of mutual induction?

Last Answer : Transformer

Tachometer works essentially as a generator with output voltage proportional to magnitude of the : -

Description : Tachometer works essentially as a generator with output voltage proportional to magnitude of the : - a) Angular Velocity of the shaft b) Torque of the shaft c) Temperature of the shaft d) Back Lash of the shaft

Last Answer : Tachometer works essentially as a generator with output voltage proportional to magnitude of the : - Angular Velocity of the shaft

A 3 phase 50 Hz induction motor has full load speed of 970 rpm. Calculate no of poles and slip frequency.

Description : A 3 phase 50 Hz induction motor has full load speed of 970 rpm. Calculate no of poles and slip frequency.

Last Answer : The number of poles in an induction motor can be calculated using the following formula: No. of poles = (120 * frequency) / speed In this case, the number of poles would be calculated as follows: No. of poles = ( ... ) - 50 Hz = 8.08 Hz So the motor has 6 poles and a slip frequency of 8.08 Hz.

Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque

Description : Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque

Last Answer : Ans: B

A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3

Description : A four pole, 60 Hz, three-phase synchronous motor comes up to 1760 RPM when started as an induction motor. What is the percent slip after the rotor field is energized? A. 0 B. 1.1 C. 2.2 D. 3.3

Last Answer : Answer: A

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

Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under no load. C. A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.

Description : Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency? A. A four-pole synchronous motor under normal load. B. A four-pole induction motor under ... A six-pole synchronous motor under normal load. D. A six-pole induction motor under full load.

Last Answer : Answer: A

The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit

Description : The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit

Last Answer : Answer: A

A four-pole 60-hertz induction motor has a synchronous speed of 1800 RPM and a slip of 4 percent at full load. What will be its full load speed? A. 1728.0 RPM B. 1730.7 RPM C. 1800.0 RPM D. 1872.0 RPM

Description : A four-pole 60-hertz induction motor has a synchronous speed of 1800 RPM and a slip of 4 percent at full load. What will be its full load speed? A. 1728.0 RPM B. 1730.7 RPM C. 1800.0 RPM D. 1872.0 RPM

Last Answer : Answer: A

A single-phase induction motor starts, comes up to about 75% rated speed, slows down to a lower speed, and accelerates again. The problem is most likely in the ____________. A. starting winding B. running winding C. starting capacitor D. running centrifugal switch

Description : A single-phase induction motor starts, comes up to about 75% rated speed, slows down to a lower speed, and accelerates again. The problem is most likely in the ____________. A. starting winding B. running winding C. starting capacitor D. running centrifugal switch

Last Answer : Answer: B

If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the main winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18

Description : If the synchronous speed of a 12 pole, polyphase, induction motor operating at 60 Hz were 600 RPM, how many poles will be required in a similar motor operating at the same frequency but having a synchronous speed of 900 RPM? A. 4 B. 6 C. 8 D. 18

Last Answer : Answer: C

A four-pole induction motor, operating on three-phase 60 cycle current will operate at approximately ___________. A. 850 RPM B. 1,150 RPM C. 1,750 RPM D. 3,550 RPM

Description : A four-pole induction motor, operating on three-phase 60 cycle current will operate at approximately ___________. A. 850 RPM B. 1,150 RPM C. 1,750 RPM D. 3,550 RPM

Last Answer : Answer: C

If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the run winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Description : If a single-phase induction motor fails to start, the problem may be _____________. A. an open in the run winding B. a shorted shunt field C. a closed centrifugal switch D. low circuit frequency

Last Answer : Answer: A

What is the rotor speed of a four pole, 60 cycle, induction motor operating at full load with 3% slip? A. 270 RPM B. 540 RPM C. 873 RPM D. 1746 RPM

Description : What is the rotor speed of a four pole, 60 cycle, induction motor operating at full load with 3% slip? A. 270 RPM B. 540 RPM C. 873 RPM D. 1746 RPM

Last Answer : Answer: D

A single-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. The problem probably lies in the ________. A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Description : A single-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. The problem ... in the ________. A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Last Answer : Answer: D

The following air gap readings were obtained from a horizontally mounted, bilge pump, induction motor, equipped with sleeve bearings: FWD END-AFT END, Top .045 - .049, Right Side .045 - .047, Left Side .045 - .047, Bottom .045 - .041 Which of the f A. both the aft and foward bearings should be replaced. B. Shims should be removed from the aft bearing. C. The forward bearing should be lowered. D. The aft bearing should be lowered.

Description : The following air gap readings were obtained from a horizontally mounted, bilge pump, induction motor, equipped with sleeve bearings: FWD END-AFT END, Top .045 - .049, Right Side .045 - .047, Left ... the aft bearing. C. The forward bearing should be lowered. D. The aft bearing should be lowered.

Last Answer : Answer: A

If a three-phase induction motor is operated under a light load and it develops an open in one of its supply lines, the motor will _____________. A. continue to run, but will vibrate and have reduced torque B. speed up due to the reduced number of poles C. run cooler due to reduced current flow D. stop

Description : If a three-phase induction motor is operated under a light load and it develops an open in one of its supply lines, the motor will _____________. A. continue to run, but will vibrate and have reduced ... speed up due to the reduced number of poles C. run cooler due to reduced current flow D. stop

Last Answer : Answer: A

A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

Description : A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

Last Answer : Answer: D

A three-phase, squirrel cage, induction motor will run hot due to a/an ______________. A. improper brush position B. reversed commutating pole C. shorted stator D. high power factor

Description : A three-phase, squirrel cage, induction motor will run hot due to a/an ______________. A. improper brush position B. reversed commutating pole C. shorted stator D. high power factor

Last Answer : Answer: C