The most appropriate operating speed in rpm of generators used in Thermal, Nuclear and ...

by

1 Answer

Answer :

The most appropriate operating speed in rpm of generators used in Thermal, Nuclear and Hydro-power plants would respectively be: 3000, 3000 and 300

by

Related questions

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

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

The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. changing the RPM of the rotor flux C. changing the phase sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Last Answer : Answer: A

Different types of bearings are designed to operate at different operating speeds. Speed is specified as the maximum (a) rpm (b) metres/second (c) metres/minute (d) metres/hour

Description : Different types of bearings are designed to operate at different operating speeds. Speed is specified as the maximum (a) rpm (b) metres/second (c) metres/minute (d) metres/hour

Last Answer : (b) metres/second

What is the safe maximum tripping speed of a turbine operating at 2500 rpm?

Description : What is the safe maximum tripping speed of a turbine operating at 2500 rpm?

Last Answer : The rule is to trip at 10 percent overspeed. Therefore, 2500 x 1.10 = 2750 rpm.

Which statement best describes the operating principle of a constant-speed propeller? a. As throttle setting is changed by the pilot, the prop governor causes pitch angle of the propeller blades to remain unchanged b. The propeller control regulates the engine RPM and in turn the propeller RPM c. A high blade angle, or increased pitch, reduces the propeller drag and allows more engine power for take-offs d. As the propeller control setting is changed by the pilot, the RPM of the engines remains constant as the pitch angle of the propeller changes

Description : Which statement best describes the operating principle of a constant-speed propeller? a. As throttle setting is changed by the pilot, the prop governor causes pitch angle of the propeller blades to ... the pilot, the RPM of the engines remains constant as the pitch angle of the propeller changes

Last Answer : b. The propeller control regulates the engine RPM and in turn the propeller RPM

Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, the unit whose governor has the zero speed droop setting will _____________. A. assume the smaller share of the load B. maintain the frequency of the system C. have poor sensitivity characteristics D. have poor power response

Description : Two AC generators of the same capacity are operating in parallel. One with a zero speed droop setting and the other with a 5% speed droop. If its capacity is not exceeded, the unit whose ... B. maintain the frequency of the system C. have poor sensitivity characteristics D. have poor power response

Last Answer : Answer: B

The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Description : The power factor of an AC generator operating singularly is determined by the __________. A. connected load B. prime mover speed C. field excitation D. generator's rated voltage

Last Answer : Answer: A

The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ____________. A. load limit settings B. idle speed settings C. speed limit settings D. speed droop settings

Description : The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ____________. A. load limit settings B. idle speed settings C. speed limit settings D. speed droop settings

Last Answer : Answer: D

Which power plant has minimum operating cost? a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Gas Turbine Power Plant Ans: A 42. Which of the following have highest operating cost? a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Solar electric power plant

Description : Which power plant has minimum operating cost? a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Gas Turbine Power Plant Ans: A 42. Which of the following have ... a) Hydroelectric power plant b) Thermal power plant c) Nuclear power plant d) Solar electric power plant

Last Answer : Ans: B

In which of the electric power generation system, the operating cost is minimum? (A) Thermal (B) Nuclear (C) Hydroelectric (D) Fast breeder reactor

Description : In which of the electric power generation system, the operating cost is minimum? (A) Thermal (B) Nuclear (C) Hydroelectric (D) Fast breeder reactor

Last Answer : (C) Hydroelectric

A cumulative dc compound motor runs at 1500 rpm. on full load. If its series field is short-circuited, its speed

Description : A cumulative dc compound motor runs at 1500 rpm. on full load. If its series field is short-circuited, its speed  (1) becomes zero (2) remains unchanged (3) increases (4) decreases

Last Answer : Increases. As it's cumulative compound motor, both series and shunt field both assist each other. If series field is short circuited, the overall field strength will decrease and atop of that ... speed is inversely proportional to field strength.  So, the speed will increase overall.

A 50 Hz, 3—phase induction motor has a full load speed of 1440 rpm. The number of poles of the motor is: ...

Description : A 50 Hz, 3—phase induction motor has a full load speed of 1440 rpm. The number of poles of the motor is:   (A)4 (8)6 (0)12  (D)8

Last Answer : Ans: A N= Ns (1-S) = NS –NS x S 1440 = Ns (1-S) Ns = 1440 / (1-S) Ns = (120 f/ p) = 120 x 50/p = 6000 p Ns will be closer to N i.e 1440 When P=2 ; Ns = 3000 rpm , not close to N When P=4 ; Ns = 1500 rpm , it is closer to N Therefore P =4 for N=1440

Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D

Description : Which of the synchroscope illustrations depicts the appropriate direction of rotation and position for closing the circuit breaker when paralleling AC generators? EL-0053 A. A B. B C. C D. D

Last Answer : Answer: D

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

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

Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions properly and trips generator #1 electrically off the bo A. Start the emergency generator. B. Ascertain cause of the low lube oil pressure. C. Strip the board of all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Description : Diesel generators #1 and #2 are operating in parallel at near full load capacity. Diesel generator #1 suddenly trips out mechanically due to low lube oil pressure. The reverse power relay functions ... all nonvital circuits. D. Secure alarms, reset reverse power relay, and restart #1 engine.

Last Answer : Answer: C

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

If three AC generators are operating in parallel, and one of them were to 'pull out' of synchronism with the other two generators, the ____________. A. normally operating AC generators will vibrate severely B. AC generator pulling out of synchronism will vibrate severely C. normally operating AC generators will overspeed and unload D. AC generator pulling out of synchronism will become motorized

Description : If three AC generators are operating in parallel, and one of them were to 'pull out' of synchronism with the other two generators, the ____________. A. normally operating AC generators will ... AC generators will overspeed and unload D. AC generator pulling out of synchronism will become motorized

Last Answer : Answer: B

Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Description : Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt ... generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Last Answer : Answer: D

When two generators are on the line and are sharing the load equally, they are said to be operating in _____________. A. frequency B. series C. parallel D. resonance

Description : When two generators are on the line and are sharing the load equally, they are said to be operating in _____________. A. frequency B. series C. parallel D. resonance

Last Answer : Answer: C

On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock B. create an isolated ground for the instrumentation C. allow for the expansion of the generator away from the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Description : On electrical generators one of the bearings is isolated from the bedplate. This insulating block should not be painted and must be kept clean to ___________. A. protect operating personnel from shock ... the prime mover as it warms up D. eliminate shaft currents to prevent damaging the bearings

Last Answer : Answer: D

Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies

Description : Electrical machinery insulation will break down more rapidly due to _________________. A. low loading of motors and generators B. frequent megger testing C. high temperatures and vibration D. high operating frequencies

Last Answer : Answer: C

Which is a function of the voltage regulators used with AC generators? A. To cut out generators when they are no longer required. B. To cut in additional generators automatically as required. C. To divide the KW load equally between generators operating in parallel. D. To divide reactive current between generators operating in parallel.

Description : Which is a function of the voltage regulators used with AC generators? A. To cut out generators when they are no longer required. B. To cut in additional generators automatically as ... between generators operating in parallel. D. To divide reactive current between generators operating in parallel.

Last Answer : Answer: D

The division of the kilowatt load between two AC generators operating in parallel is controlled by the settings and characteristics of the _____________. A. voltage regulators B. field rheostats C. reverse power relays D. prime mover governors

Description : The division of the kilowatt load between two AC generators operating in parallel is controlled by the settings and characteristics of the _____________. A. voltage regulators B. field rheostats C. reverse power relays D. prime mover governors

Last Answer : Answer: D

Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Description : Kilowatt load is divided between two AC generators operating in parallel by _____________. A. adjusting the governor controls B. varying the excitation voltage C. increasing both prime mover speeds simultaneously D. decreasing both prime mover speeds simultaneously

Last Answer : Answer: A

Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The series fields of both generators are connected in parallel.

Description : Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats ... are connected in series. D. The series fields of both generators are connected in parallel.

Last Answer : Answer: D

List the factors that affect the load sharing in parallel operating generators?

Description : List the factors that affect the load sharing in parallel operating generators?

Last Answer : The total active and reactive power delivered to the load, connected across the common bus-bars, are shared among Synchronous generators, operating in parallel, based on the following three factors ... characteristic/input · Excitation level and · Percentage synchronous impedance and its R/X ratio

Two synchronous generators G1, G2 are operating in parallel and are equally sharing KVAR (Lag) component

Description : Two synchronous generators G1, G2 are operating in parallel and are equally sharing KVAR (Lag) component of load. To shift part of KVAR from G2 to G1, while keeping terminal voltage fixed, the following action must be done

Last Answer : Two synchronous generators G1, G2 are operating in parallel and are equally sharing KVAR (Lag) component of load. To shift part of KVAR from G2 to G1, while keeping terminal voltage fixed, the following action must be done Raise If1 and lower If2

Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power

Description : Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power characteristics have a common slope of 1 MW/Hz and the no-load frequencies of the generators are 51.5 Hz and 51.0 Hz, ... system frequency is (A) 50 Hz (B) 51 Hz (C) 51.25 Hz (D) 51.5 Hz

Last Answer : Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power characteristics have a common slope of 1 MW/Hz and the no-load frequencies of the generators are 51.5 Hz and 51.0 Hz, respectively. Then the system frequency is 50 Hz

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.

A wheel 8 mts in diameter coasts to rest from a speed of 800 rpm in 10 minutes. Its angular deceleration is a.308/min2 b.683 rad/min2 c.502 rad/min2 d.107 dynes e.809 rad/min2

Description : A wheel 8 mts in diameter coasts to rest from a speed of 800 rpm in 10 minutes. Its angular deceleration is a.308/min2 b.683 rad/min2 c.502 rad/min2 d.107 dynes e.809 rad/min2

Last Answer : c. 502 rad/min2

Is it best to get a turntable with one speed, 33.3 RPM, or one with an additonal speed as well?

Description : Is it best to get a turntable with one speed, 33.3 RPM, or one with an additonal speed as well?

Last Answer : Is better to have a turn table with different speed options, you can mix music/vinyls that have different speeds.

determine the speed of rotation of a 20 tooth gear when it is driven by a 40 tooth gear and rotating at 10 rpm?

Description : determine the speed of rotation of a 20 tooth gear when it is driven by a 40 tooth gear and rotating at 10 rpm?

Last Answer : i am the one that asked i dont know the answer

A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke engine (b) Be half that of the four stroke engine (c) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine

Description : A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke ... ) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine

Last Answer : Ans :c

Piston speed is equal to a. stroke x rpm b. (stroke x rpm) / 2 c. 2 x stroke x rpm d. 4 x stroke x rpm

Description : Piston speed is equal to a. stroke x rpm b. (stroke x rpm) / 2 c. 2 x stroke x rpm d. 4 x stroke x rpm

Last Answer : ANSWER c. 2 x stroke x rpm

A four pole turbogenerator is used in conjunction with a 160 pole propulsion motor. If the generator is turning at 3,200 RPM, what is the current speed of the propeller? A. 40 RPM B. 60 RPM C. 80 RPM D. 100 RPM

Description : A four pole turbogenerator is used in conjunction with a 160 pole propulsion motor. If the generator is turning at 3,200 RPM, what is the current speed of the propeller? A. 40 RPM B. 60 RPM C. 80 RPM D. 100 RPM

Last Answer : Answer: C

An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, the cycles will _____________. A. remain at 60 Hz B. increase to 61 Hz C. decrease to 59 Hz D. increase to 63 Hz

Description : An AC generator produces 60 Hz at 1800 RPM. If the generator speed is increased to 1830 RPM, the cycles will _____________. A. remain at 60 Hz B. increase to 61 Hz C. decrease to 59 Hz D. increase to 63 Hz

Last Answer : Answer: B

The most practical method of controlling the RPM of a step-speed AC motor is to _____________. A. change input voltage B. vary the number of poles C. vary power factor D. change the number of brushes

Description : The most practical method of controlling the RPM of a step-speed AC motor is to _____________. A. change input voltage B. vary the number of poles C. vary power factor D. change the number of brushes

Last Answer : Answer: B

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 four-pole, 60 cycle, squirrel-cage motor has a full load speed of 1725 RPM. What will be the percent of slip at full load? A. 4.16 B. 4.34 C. 95.66 D. 95.84

Description : A four-pole, 60 cycle, squirrel-cage motor has a full load speed of 1725 RPM. What will be the percent of slip at full load? A. 4.16 B. 4.34 C. 95.66 D. 95.84

Last Answer : Answer: A

The prime mover of an AC two pole main propulsion generator drives the generator at 3600 RPM. If the main propulsion motor has 80 poles, what will be the propeller speed? A. 45 RPM B. 80 RPM C. 90 RPM D. 180 RPM

Description : The prime mover of an AC two pole main propulsion generator drives the generator at 3600 RPM. If the main propulsion motor has 80 poles, what will be the propeller speed? A. 45 RPM B. 80 RPM C. 90 RPM D. 180 RPM

Last Answer : Answer: C

As shown in the illustration, when the 'speed control' system is in 'SPLIT' _______________. EL-0096 A. Relays #1, #5 and #8 are not used B. the 'slew rated controller' is grounded through Relay #6 C. the RPM 'function generator' and 'thrust levers' have no control D. the 'E/P converters' are bypassed and air is fed directly to the governors via the 'load sharing valve'

Description : As shown in the illustration, when the 'speed control' system is in 'SPLIT' _______________. EL-0096 A. Relays #1, #5 and #8 are not used B. the 'slew rated controller' is grounded through Relay ... E/P converters' are bypassed and air is fed directly to the governors via the 'load sharing valve'

Last Answer : Answer: C

The synchronous speed of an induction motor is the ________. A. speed at which the rotor turns B. speed of the rotating field C. frequency of the rotor current D. slip in per cent of rotor RPM

Description : The synchronous speed of an induction motor is the ________. A. speed at which the rotor turns B. speed of the rotating field C. frequency of the rotor current D. slip in per cent of rotor RPM

Last Answer : Answer: B

The speed of a rotary drum vacuum filter may be about __________ rpm. (A) 1 (B) 50 (C) 100 (D) 500

Description : The speed of a rotary drum vacuum filter may be about __________ rpm. (A) 1 (B) 50 (C) 100 (D) 500

Last Answer : (A) 1

rpm of a trommel at critical speed is given by (where, D = Diameter of trommel in ft) (A) 76.65/D (B) 76.65/√D (C) 76.65/D2 (D) 76.75 √D

Description : rpm of a trommel at critical speed is given by (where, D = Diameter of trommel in ft) (A) 76.65/D (B) 76.65/√D (C) 76.65/D2 (D) 76.75 √D

Last Answer : (B) 76.65/√D

A propeller agitator (A) Produces mainly axial flow (B) Is used for mixing high viscosity pastes (C) Runs at very slow speed (2 rpm) (D) All (A), (B) and (C)

Description : A propeller agitator (A) Produces mainly axial flow (B) Is used for mixing high viscosity pastes (C) Runs at very slow speed (2 rpm) (D) All (A), (B) and (C)

Last Answer : (A) Produces mainly axial flow

A flywheel of moment of inertia 9.8kgm 2 fluctuates by 30 rpm for a fluctuation in energy of 1936 joules. The means speed of flywheel is (in rpm) 1. 600 2. 900 3. 968 4. 2940

Description : A flywheel of moment of inertia 9.8kgm 2 fluctuates by 30 rpm for a fluctuation in energy of 1936 joules. The means speed of flywheel is (in rpm) 1. 600 2. 900 3. 968 4. 2940

Last Answer : 1. 600