To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed

To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. stowed upright on its shaft C. supported by two 'V' notched wood blocks D. returned to the frame as soon as the bearings are removed
by

1 Answer

Answer :

Answer: C
by

Related questions

To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. wrapped in several layers of heavy paper or cardboard C. supported by flat wood blocks on the workbench D. returned to the frame as soon as the bearings are removed

Description : To protect the rotor of a motor disassembled for maintenance or overhaul, it should be ___________________. A. suspended by wire slings in one corner of the shop B. wrapped in several layers of heavy ... flat wood blocks on the workbench D. returned to the frame as soon as the bearings are removed

Last Answer : Answer: B

When disassembling electric motors for maintenance or overhaul, ________________. A. punch mark frame and end bells for proper assembly B. wrap bearings in lint free cloths if they are to be reused C. tag and store small parts in a box D. all of the above

Description : When disassembling electric motors for maintenance or overhaul, ________________. A. punch mark frame and end bells for proper assembly B. wrap bearings in lint free cloths if they are to be reused C. tag and store small parts in a box D. all of the above

Last Answer : Answer: D

Rotor shaft of a large electric motor supported between short bearings at both ends shows a deflection of 1.8 mm in middle of motor. Assuming rotor to be perfectly balanced and supported at knife edges at both ends, likely critical speed (rpm) of shaft isA 350 B 4430 C 705 D 2810

Description : Rotor shaft of a large electric motor supported between short bearings at both ends shows a deflection of 1.8 mm in middle of motor. Assuming rotor to be perfectly balanced and supported at knife edges at both ends, likely critical speed (rpm) of shaft isA 350 B 4430 C 705 D 2810

Last Answer : C 705

The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the bearings C. strictly converted to heat generated by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

Description : The reactive power drawn by a motor from an AC generator is the power which is _____________. A. used to establish the magnetic field of the motor B. lost in overcoming friction in the ... by current flow through the windings D. transmitted directly through the rotor shaft to perform useful work

Last Answer : Answer: A

In the illustrated motor, roller bearings are used because __________. EL-0001 A. of their ability to absorb moderate thrust loads B. they electrically insulate the rotor from the frame reducing cross-currents C. the shafting and end bells do not require as close a tolerance to properly fit this type of bearing D. the clearance between the rotor and stator is generally as close as mechanical tolerance will permit

Description : In the illustrated motor, roller bearings are used because __________. EL-0001 A. of their ability to absorb moderate thrust loads B. they electrically insulate the rotor from the frame reducing ... clearance between the rotor and stator is generally as close as mechanical tolerance will permit

Last Answer : Answer: D

One of the generator or motor bearings is generally insulated from the end housing in order to prevent ________. A. rapid brush wear B. current leakage from the shaft C. excessive field winding heat D. circulation of shaft currents induced in the machine's frame

Description : One of the generator or motor bearings is generally insulated from the end housing in order to prevent ________. A. rapid brush wear B. current leakage from the shaft C. excessive field winding heat D. circulation of shaft currents induced in the machine's frame

Last Answer : Answer: D

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

A company has to choose between two projects whose cash flows are as indicated below; Project 1: i. Investment – Rs. 15 Lakhs ii. Annual cost savings – Rs. 4 lakhs. iii. Bi-annual maintenance cost – Rs. 50,000/- iv. Reconditioning and overhaul during 5th year: 6 lakhs v. Life of the project – 8 years vi. Salvage value – Rs. 5 lakhs Project 2: vii. Investment – Rs. 14 Lakhs viii. Annual cost savings – Rs. 3.5 lakhs. ix. Annual Maintenance cost – Rs. 20,000/- x. Reconditioning and overhaul during 4th year: 5 lakhs xi. Life of the project – 8 years xii. Salvage Value- 2 lakhs Which project should the company choose? The annual discount rate is 12

Description :  A company has to choose between two projects whose cash flows are as indicated  below; Project 1:  i. Investment - Rs. 15 Lakhs ii. Annual cost savings - Rs. 4 lakhs. iii. Bi-annual ... years xii. Salvage Value- 2 lakhs Which project should the company choose? The annual discount rate is 12

Last Answer : Year Project 1 Project 2 Outgo Saving NPV Outgo Saving NPV 0 15.0 0 =-15.0 14.0 0 = -14 1 0 4.0 = (4 / (1+.12)1 = 3.571 0.2 3.5 = (3.3 / (1+.12)1 = 2.95 2 0.5 4.0 = (3.5 / (1+.12)2 = 2.79 0.2 3.5 ... (1+.12)8 = 3.43 0.2 5.5  (3.5+2) = (5.3 / (1+.12)8 = 2.14 NPV = + 2.301 @12% = + 0.15

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

The air gap in an induction motor should be periodically checked with a feeler gage to prevent possible ___________. A. rotor contact with the stator B. axial misalignment of the rotor C. damage to the motor bearings D. electrical damage to the bearings

Description : The air gap in an induction motor should be periodically checked with a feeler gage to prevent possible ___________. A. rotor contact with the stator B. axial misalignment of the rotor C. damage to the motor bearings D. electrical damage to the bearings

Last Answer : Answer: A

When removing ball or roller bearings from the shaft of a motor, you should use a _____________. A. rawhide hammer B. brass mallet C. wheel puller D. soft iron pry bar

Description : When removing ball or roller bearings from the shaft of a motor, you should use a _____________. A. rawhide hammer B. brass mallet C. wheel puller D. soft iron pry bar

Last Answer : Answer: C

A handheld digital tachometer could give a bad reading if ___________________. A. aimed directly at the shaft B. partially aimed at a 60 Hz. fluorescent light C. positioned 5-10 inches from the shaft D. the tape is too shiny

Description : A handheld digital tachometer could give a bad reading if ___________________. A. aimed directly at the shaft B. partially aimed at a 60 Hz. fluorescent light C. positioned 5-10 inches from the shaft D. the tape is too shiny

Last Answer : Answer: B

The torque produced by a motor when its shaft will not turn, even though rated voltage is applied to the stator, is known as _____________. A. locked-rotor torque B. pullout torque C. breakdown torque D. torque margin

Description : The torque produced by a motor when its shaft will not turn, even though rated voltage is applied to the stator, is known as _____________. A. locked-rotor torque B. pullout torque C. breakdown torque D. torque margin

Last Answer : Answer: A

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

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 fo A. The aft bearing should be realigned or 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

In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. squirrel cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

Description : In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. ... cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

Last Answer : Answer: C

Routine A.C. motor maintenance should include periodic ______________. A. thermometer readings at normal loads to detect abnormal temperature rises B. inspection of the motor's internals for loose rotor bars or field poles C. bearing replacement each year using sealed units if available D. all of the above

Description : Routine A.C. motor maintenance should include periodic ______________. A. thermometer readings at normal loads to detect abnormal temperature rises B. inspection of the motor's internals for loose rotor bars ... C. bearing replacement each year using sealed units if available D. all of the above

Last Answer : Answer: A

Which of the following are functions of bearings? a) Ensure free rotation of shaft with minimum friction b) Holding shaft in a correct position c) Transmit the force of the shaft to the frame d) All of the listed

Description : Which of the following are functions of bearings? a) Ensure free rotation of shaft with minimum friction b) Holding shaft in a correct position c) Transmit the force of the shaft to the frame d) All of the listed

Last Answer : d) All of the listed

The small circular symbols to which wire '52N57E' is connected at coordinates '57L' and '57P' shown in the illustration represent ___________________. EL-0100 A. relay contact solder points B. wire wrap connections C. terminal board screws D. switch contact terminals

Description : The small circular symbols to which wire '52N57E' is connected at coordinates '57L' and '57P' shown in the illustration represent ___________________. EL-0100 A. relay contact solder points B. wire wrap connections C. terminal board screws D. switch contact terminals

Last Answer : Answer: C

On large generators, space heaters are used to ____________. A. keep the machine at ambient tmperature of the machinery space B. maintain rotor and stator winding temperatures above the dew point to prevent the formation of condensation C. prevent condensation in the lube oil D. prevent electrolysis due to condensation in the bearings

Description : On large generators, space heaters are used to ____________. A. keep the machine at ambient tmperature of the machinery space B. maintain rotor and stator winding temperatures above the dew point ... C. prevent condensation in the lube oil D. prevent electrolysis due to condensation in the bearings

Last Answer : Answer: B

Air gap readings for electrical generating equipment should be taken periodicly. This is to _______. I. determine the condition of the bearings II. prevent damage to the rotor and stator A. I only B. II only C. both I and II D. neither I or II

Description : Air gap readings for electrical generating equipment should be taken periodicly. This is to _______. I. determine the condition of the bearings II. prevent damage to the rotor and stator A. I only B. II only C. both I and II D. neither I or II

Last Answer : Answer: C

When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across the top of the first line fuse and the bottom of the third line fuse C. apply the voltage tester across the bottoms of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Description : When testing for blown fuses in a three-phase supply circuit to a motor, you should first ___________________. A. apply the megger across the tops of the line fuses B. apply an ammeter diagonally across ... of the line fuses D. ensure the circuit is de-energized, and then use a continuity tester

Last Answer : Answer: D

The basic type of D.C. motor speed control where a generator armature directly feeds the motor armature and the motor and generator fields are excited by a separate D.C. source is called ___________________. A. Burmeister-Wain B. Ward-Leonard C. Sperry-Rand D. Atlas-Copco

Description : The basic type of D.C. motor speed control where a generator armature directly feeds the motor armature and the motor and generator fields are excited by a separate D.C. source is called ___________________. A. Burmeister-Wain B. Ward-Leonard C. Sperry-Rand D. Atlas-Copco

Last Answer : Answer: B

Modern handheld digital tachometers operate by counting light pulses returned to the unit by ______________. A. the tach generator B. either the coupling or shaft C. a small bulb attached to the shaft D. a piece of reflective tape

Description : Modern handheld digital tachometers operate by counting light pulses returned to the unit by ______________. A. the tach generator B. either the coupling or shaft C. a small bulb attached to the shaft D. a piece of reflective tape

Last Answer : Answer: D

The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it?

Last Answer : The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it helps in reducing the tendency of the rotor teeth to remain under the stator teeth.

What are the effects of broken rotor bars and broken shaft parts?

Description : What are the effects of broken rotor bars and broken shaft parts?

Last Answer : Broken rotor bars a. High stator current and over heat of stator winding. b. More harmonic currents in end parts. c. High vibration. Broken shaft or parts a. Stator winding loose bracing. b. Rotor high vibration and bearing vibration. c. Frame vibration and more harmonics in side bands. 

If overloading a DC machine becomes necessary in an emergency, you should ____________. A. cool the machine with portable blowers and fans B. hold thermal overload relays open with blocks of wood C. inject small amounts of CO2 into the windings for cooling D. increase the residual magnetism value of windings to reduce eddy currents

Description : If overloading a DC machine becomes necessary in an emergency, you should ____________. A. cool the machine with portable blowers and fans B. hold thermal overload relays open with blocks of ... the windings for cooling D. increase the residual magnetism value of windings to reduce eddy currents

Last Answer : Answer: A

The frequency output of an operating alternator is controlled by the _____________. A. relative speed of the rotor poles B. number of turns of wire in the armature coil C. strength of the magnets used D. output voltage

Description : The frequency output of an operating alternator is controlled by the _____________. A. relative speed of the rotor poles B. number of turns of wire in the armature coil C. strength of the magnets used D. output voltage

Last Answer : Answer: A

If Martha is standing on a street corner in a big city facing south. She walks blocks to the south. Then she turns right and walks blocks. Then she turns right and walks blocks. Then she turns right a?

Description : If Martha is standing on a street corner in a big city facing south. She walks blocks to the south. Then she turns right and walks blocks. Then she turns right and walks blocks. Then she turns right a?

Last Answer : North

Mahatma Gandhi suspended the Civil Disobedience Campaign and agreed to attend the Second Round Table Conference in London, from where he returned empty handed to India. -SST 10th

Description : Mahatma Gandhi suspended the Civil Disobedience Campaign and agreed to attend the Second Round Table Conference in London, from where he returned empty handed to India. -SST 10th

Last Answer : Gandhiji returned to India and reached Bombay on 28th December, 1931. The first step he took was to renew the Civil Disobedience Movement. This decision was taken in the Congress Working Committee ... Legislature. Gandhiji opposed this move and he was sent to yerwada jail near Poona (Pune).

How are slings Inspected?

Description : How are slings Inspected?

Last Answer : All slings must be inspected before every use and periodically it should be inspected thoroughly and shall be rejected, if found wear of the one third the original outside diameter of outside individual wires, ... and rust. Before use the slings has to be colour coded as per the month colour code.

The bearings used to support the rotor shafts are generally?

Last Answer : The bearings used to support the rotor shafts are generally ball bearings.

It appears that modern students are adopting innovative methods of flattery and short-cuts in their studies. What do you think about its remedial measures? Options: A) Use these youngsters for your personal gains B) Teacher must protect their own faces from them C) Favourable remedial measures should be implemented to make them strong and upright citizens by the teachers D) As it is the trend of society there is nothing wrong in it

Description : It appears that modern students are adopting innovative methods of flattery and short-cuts in their studies. What do you think about its remedial measures? Options: A) Use these youngsters for your personal gains ... by the teachers D) As it is the trend of society there is nothing wrong in it

Last Answer : Favourable remedial measures should be implemented to make them strong and upright citizens by the teachers

Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding temperature with an accurate mercury thermometer C. periodic cleaning of the winding insulation with an approved solvent D. making sure that the units are close to bulkheads or corners to protect them from damage

Description : Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding ... . making sure that the units are close to bulkheads or corners to protect them from damage

Last Answer : Answer: A

Which bearings preferred for all large power motor?

Description : Which bearings preferred for all large power motor?  

Last Answer : Plain bearings  

The meter indicating the position of the 'bridge Thrust lever' shown in the illustration is located ___________________. EL-0095 A. in the Engine Control Room B. on the Bridge C. in the Captain's office D. in the Chief Engineer's office

Description : The meter indicating the position of the 'bridge Thrust lever' shown in the illustration is located ___________________. EL-0095 A. in the Engine Control Room B. on the Bridge C. in the Captain's office D. in the Chief Engineer's office

Last Answer : Answer: A

An across-the-line starter provides ___________________. A. maximum torque B. slow starting power C. high speed D. reduced voltage

Description : An across-the-line starter provides ___________________. A. maximum torque B. slow starting power C. high speed D. reduced voltage

Last Answer : Answer: A

To minimize magnetic field interaction between electrical conductors in physical proximity, it is best to keep them ___________________. A. parallel and as close as possible to each other B. at right angles and as close as possible to each other C. parallel to and as far as practicable from each other D. at right angles and as far as practicable from each other

Description : To minimize magnetic field interaction between electrical conductors in physical proximity, it is best to keep them ___________________. A. parallel and as close as possible to each other B. at right angles ... practicable from each other D. at right angles and as far as practicable from each other

Last Answer : Answer: D

In a cartridge-type fuse, the metal element is contained in a ___________________. A. porcelain window B. thermal cut out C. fiber tube D. flasher device

Description : In a cartridge-type fuse, the metal element is contained in a ___________________. A. porcelain window B. thermal cut out C. fiber tube D. flasher device

Last Answer : Answer: C

When troubleshooting most electronic circuits, 'loading effect' can be minimized by using a voltmeter with a/an ___________________. A. input impedance much greater than the impedance across which the voltage is being measured B. input impedance much less than the impedance across which the voltage is being measured C. sensitivity of less than 1000 ohms/volt D. sensitivity of more than 1000 volts/ohm

Description : When troubleshooting most electronic circuits, 'loading effect' can be minimized by using a voltmeter with a/an ___________________. A. input impedance much greater than the impedance across which the voltage ... sensitivity of less than 1000 ohms/volt D. sensitivity of more than 1000 volts/ohm

Last Answer : Answer: A

In sliding contact bearings, a positive pressure can be built up and a load supported by a fluid only by the use of a: [IES-2005] (a) Diverging film (b) Converging-diverging film (c) Converging film (d) Flat film

Description : In sliding contact bearings, a positive pressure can be built up and a load supported by a fluid only by the use of a: [IES-2005] (a) Diverging film (b) Converging-diverging film (c) Converging film (d) Flat film

Last Answer : (c) Converging film

The effective span of a simply supported slab, is (A) Distance between the centres of the bearings (B) Clear distance between the inner faces of the walls plus twice the thickness of the wall (C) Clear span plus effective depth of the slab (D) None of these

Description : The effective span of a simply supported slab, is (A) Distance between the centres of the bearings (B) Clear distance between the inner faces of the walls plus twice the thickness of the wall (C) Clear span plus effective depth of the slab (D) None of these

Last Answer : Answer: Option B

The effective span of a simply supported slab is (a) Distance between the centers of the bearings (b) Clear distance between the inner faces of the walls plus twice he thickness of the slab. (c) Cleat spa plus effective depth of the slab. (d) All the above

Description : The effective span of a simply supported slab is (a) Distance between the centers of the bearings (b) Clear distance between the inner faces of the walls plus twice he thickness of the slab. (c) Cleat spa plus effective depth of the slab. (d) All the above

Last Answer : (c) Cleat spa plus effective depth of the slab.

Which of the following conditions will occur if the solenoid coil burns out on a cargo winch with an electrical brake? A. The brake will be set by spring force. B. The motor will overspeed and burn up. C. The load suspended from the cargo boom will fall. D. Nothing will happen; the winch will continue to operate as usual.

Description : Which of the following conditions will occur if the solenoid coil burns out on a cargo winch with an electrical brake? A. The brake will be set by spring force. B. The motor will overspeed and burn ... the cargo boom will fall. D. Nothing will happen; the winch will continue to operate as usual.

Last Answer : Answer: A

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated

Description : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A 

When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of - (1) surface tension (2) capillarit (3) viscosity (4) diffusion

Description : When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of - (1) surface tension (2) capillarit (3) viscosity (4) diffusion

Last Answer : (1) surface tension Explanation: Diffusion is the spreading – mixing of gases through molecular motion.