Description : Moisture accumulating in electric motors and generator windings having a cold insulation resistance greater than 50,000 ohms may be baked out with internal heat. This heat can be developed by ____________. ... an electric welder and feeding it into the armature while running the motor at full speed
Last Answer : Answer: A
Description : Universal motors will operate on AC or DC current, and are generally found in _____________. A. portable tools B. large pump motors C. turbo electric main motors D. forced draft fans
Description : Electric motors intended for use outside the engine room and boiler room are frequently rated to run at a designed ambient temperature of 40°C. What is the equivalent temperature in degrees Fahrenheit? A. 54.2°F B. 72.0°F C. 104.0°F D. 129.6°F
Last Answer : Answer: C
Description : The failure of ball bearings used in electric motors can result from _____________. A. failure to clean the bearing before repacking B. failure to maintain proper alignment C. excess lubrication forcing the bearing full of grease and eliminating all areas of expansion D. all of the above
Last Answer : Answer: D
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
Description : Which of the following electric motors would be the safest and most reliable to use on the main deck of a vessel in foul weather conditions? A. Sealed motors B. Drip proof motors C. Enclosed motors D. Watertight motors
Description : How Many Types Of Electric Motors Are There?
Last Answer : Mainly there are two types of electric motors: AC motors DC motors
Description : Are electric motors used in the refrigerator!
Last Answer : Do you have a plug that you insert into a wall socket? If so, then yes.
Description : How many types of electric motors ?
Last Answer : 2 types of electric motors.
Description : Where can I find electric motors online?
Last Answer : One online store you can buy electric motors at is "ElectricMotors.com" They have a pretty good range of motors to choose from like jet pump, compressors, conveyors and pool motors.
Description : Do surplus electric motors normally not work very well?
Last Answer : Surplus electric motors do usually work very well. I am thinking that you could have accidentally broken it when you bought it. I would bring it back to the store just in case!
Description : Can you still get up and go with electric car motors?
Last Answer : Most electric cars have a top speed limit of around 70mph. I would find a dealership, and then I would contact someone in customer service with any questions. They should be able to assist you and point you in the right direction.
Description : Which of the following is not a source of industrial noise? A. Automobile ignition B. Sun C. Electric Motors D. Leakage from high voltage line
Last Answer : B. Sun
Description : The compound of silicon used as insulating material for electric motors/appliances is
Last Answer : silicone.
Description : Match List -I (Bearings) with List-II (Applications) and select the using the codes given below the lists: [IAS-1998] List -I List-II A. Journal bearing 1. Electric motors B. Thrust bearing 2. Watches C. Conical pivot bearing 3. Marine ... D (a) 3 4 1 2 (b) 4 2 1 3 (c) 3 4 2 1 (d) 4 2 3 1
Last Answer : (c) 3 4 2 1
Description : Products on which labeling is voluntary are a) Electric geysers b) Induction motors b) Ceiling fans d) All of the above
Last Answer : All of the above
Description : DC motors converts electrical into ___ energy. A. Mechanical B. Wind C. Electric D. None
Last Answer : A. Mechanical
Description : State types of enclosures for electric motors.
Last Answer : Types of enclosures for Electric Motor: i) Open type enclosure:- ii) Screen Protected enclosure iii) Drip proof (moisture) enclosure: iv) Flame (Fire) proof enclosure:- v) Totally enclosed type enclosure:- vi) Pipe ventilated totally enclosed type enclosure:
Description : Suggest electric motors for i) traction ii) crane iii) lathe machine iv) domestic fan.
Last Answer : i) Traction :- DC Series motor ii) Crane :- DC Series motor iii) Lathe machine :- 3 phase Induction motor or DC shunt motor iv) Domestic fan :- 1 phase induction motor
Description : State which electric motors are generally used in electro agro systems with reason.
Last Answer : 1) 3 phase induction motor is used in electro agro system for water pumping from wells as 3 phase ac supply is easily available, cost of induction motor is less, maintenance free being rugged ... as 1 phase ac supply is easily available for domestic purpose, repair is simple and easily available.
Description : Define load equalisation for electric motors. Explain how it is obtained for electric motors.
Last Answer : Define load equalization for electric Motor: There are many types of load which are fluctuating in nature e.g. wood cutting m/c, Rolling mill. Etc. For such type of loads, load equalization is ... increases so cost of cable increases, Hence it is necessary to smooth out load fluctuations on motor.
Description : Carbon brushes are used in electric motors to: (1) Brush off carbon deposit on the commutator (2) Provide a path for flow of current (3) Prevent overheating of armature windings (4) Prevent sparking during commutation
Last Answer : Carbon brushes are used in electric motors to: Provide a path for flow of current.
Description : The efficiencies of transformers compared with that of electric motors of the same power are?
Last Answer : Transformers have high efficiency than the same ratted motors
Description : Unless it can be shown that a 45°C ambient temperature will not be exceeded, motors within a machinery space must be designed for an ambient temperature of _____________. A. 45°C B. 50°C C. 55°C D. 60°C
Last Answer : Answer: B
Description : As shown in the illustration, the electrical symbol is used to indicate which of the listed types of motors? EL-0054 A. Shunt motor. B. Series motor. C. Compound motor. D. Tri-field motor.
Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. offer infinite speed variation D. all of the above
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.
Description : Which of the following is a characteristic of fractional horsepower repulsion start motors? A. They start with a rotating stator field. B. The short circuiting ring is removed from the commutator while ... brushes are removed from the commutator while starting. D. They have a low starting torque.
Description : Electrical failures in motors are caused by the breakdown of insulation, which may be caused by _____________. A. penetration of moisture B. accumulation of dirt C. overheating D. all of the above
Description : The armature cores of the D.C. motors are constructed with laminations to ___________. A. eliminate hysteresis B. minimize brush sparking C. reduce eddy current losses D. compensate for armature reaction
Description : Some large A.C. motors are equipped with with heaters. These could be ___________. I. resistance heaters bolted directly to the frame II. low voltage windings embedded in the motor windings A. I only B. II only C. either I or II D. neither I or II
Description : An overload in which of the listed motors will result in the illumination of an indicating light at the propulsion control station alarm panel? A. Fuel pump motor B. Steering motor C. Condensate pump motor D. Forced draft blower motor
Description : In addition to undercutting the mica, proper maintenance of a D.C. motor's commutator includes _______________. A. side-cutting the copper segments and insulating the slots B. coating the copper surface with light machine ... in an oven at a maximum of 95°C for not over 8 hours D. all of the above
Description : If a unloaded shunt motor's field were weakened by rheostat resistance or by an open circuit, the motor would _________. A. overspeed due to reduced CEMF B. stop because of low flux C. continue to run at base speed D. slow down and overheat
Description : All of the following items can be used in the maintenance of a D.C. propulsion motor's commutator EXCEPT _______________. A. a canvas wiper B. safety solvent C. abrasive dressing stones D. sandpaper
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
Description : As shown in the illustration, the D.C. motor's direction of rotation in changed by changing the _________________. EL-0101 A. polarity of the generator field B. direction of three-phase motor rotation C. direction of generator rotation D. polarity of the motor field
Description : Complete maintenance of electrical motors should include periodic checks for machine _____________. A. vibration B. watertight integrity C. speed droop D. reactive power
Description : The operator of electrical motors should keep a constant check on the loads they carry because _____________. A. low loads necessitate frequent insulation cleaning B. exceeding nameplate values shortens ... wasted if full loading is not utilized D. power factor correction methods are load dependent
Description : In the construction of D.C. motors, parts of both the series and shunt fields are wound on the _____________. A. opposite main pole B. rotor core C. interpole D. same main pole
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
Description : The air gap provided in induction motors should be checked periodically with a feeler gage to detect an unequal air gap and _____________. A. decreased motor magnetizing current B. hysteresis loses C. increased power factor D. mechanical damage to the rotor
Description : Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound
Description : An advantage of DC motors over AC motors is that they _____________. A. are less expensive B. require less maintenance C. can be started across the line D. offer a more effective means of controlling speed
Description : Shunt, series, and compound wound motors, are all DC motors designed to operate from _____________. A. constant potential, variable current DC sources B. variable potential, constant current DC ... C. variable potential, variable current DC sources D. constant potential, constant current DC sources
Description : The function of the autotransformers used with the starters of large AC motors is to provide _____________. A. increased voltage for starting B. increased torque for starting C. reduced voltage for starting D. speed control
Description : What is the purpose of each of the 'signal conditioners' (6000F085 / AH170 / F125) shown in the illustration? EL-0094 A. Convert the varying signal from its particular sensor and deliver a ... the 'setpoint module' in order to keep the pressure or temperature at its sensor at set limits.
Description : Most three-phase induction motors of five horsepower or less, are started by _____________. A. autotransformer starters B. resistor starters C. across-the-line starters D. reactor starters
Description : Handheld phase sequence indicators are useful when ________. A. preparing to parallel alternators B. connecting lighting branch circuits C. troubleshooting DC motors D. connecting shore power lines to the ship