1 Answer

Answer :

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

Related questions

Description : The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be

Last Answer : The rotor impedance of a slip ring induction motor is (0.1 + j0.6)Ohm/ ph . The resistance/ph to be inserted into rotor to get maximum torque at starting should be 0.5 Ohm

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

Description : Ratio of the rotor reactance X to the rotor resistance R for a two-phase servo motor (A) is equal to that of a normal induction motor (B) is less than that of a normal induction motor (C) ... than that of a normal induction motor (D) may be less or greater than that of a normal induction motor

Last Answer : C

Last Answer : Locked rotor current of a shaded pole motor is slightly more than full load current.

Last Answer : The rotor of a hysteresis motor is made of chrome steel.

Last Answer : In a hysteresis motor, the rotor must have retentivity.

Last Answer : The rotor developed by a single-phase motor at starting is zero.

Description : Salient pole rotor is use for which speed?

Last Answer : Salient pole rotor is use for low and medium speed prime movers.

Description : Which rotor is use for high speed in turbo alternators?

Last Answer : Non-salient pole rotor is used for high speed in turbo alternators.

Description : An electric motor in which both stator field and rotor rotates with same speed is called?

Last Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.

Description : What is the rotor of a motor?

Last Answer : Rotor is the rotating or moving part in motor and generator.

Last Answer : The insulating material used between the commutator segments is normally mica.

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Description : The storage battery generally used in electric power stations is  (1) zinc carbon battery (2) lead acid battery (3) nickel cadmium battery (4) lithium -ion battery

Last Answer : The storage battery generally used in electric power stations is lead acid battery 

Description : The damping winding in synchronous motor is generally used to?

Last Answer : The damping winding in synchronous motor is generally used to provide starting torque and prevent hunting.

Description : Draw a neat sketch and explain the accessory used to support long work.

Last Answer : Accessory to support long work: A steady rest is a tool for a lathe, enabling a machinist to make deep cuts in long, slender stock, bore out thin pieces of metal, and generally keeps thin stuff straight. ... tool that follows the cutter, a steady rest is firmly attached to the bed of a lathe.

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

Description : Deep groove ball bearings are used for (a) heavy thrust load only (b) the small angular displacement of shafts (c) radial load at high speed (d) combined thrust and radial loads at high speed

Last Answer : (d) combined thrust and radial loads at high speed

Description : Which one of the following types of bearings is employed in shafts of gearboxes of automobiles? [IES-1999] (a) Hydrodynamic journal bearings (b) Multi-lobed journal bearings (c) Antifriction bearings (d) Hybrid journal bearings

Last Answer : (c) Antifriction bearings

Description : How much money should I ask for our used dryer?

Last Answer : I googled and it looked like people ask $400 to $600 for the washer dryer set, but I didn't click and see how old they are. So, I guess you could ask $200-$300 maybe? I really have no knowledge of ... eBay and Craig's list, and see if you can find some competition to get a rough idea for your area.

Description : Bull riding vest?

Last Answer : answer:They make bull riding vests? Wow, I learn so much here!!! Have you tried eBay?

Description : Used Bicycles

Last Answer : Most people are apprehensive and reluctant to buy hand-me-downs, especially when it comes to items with which their lives have to depend on - a prime example of which is a bicycle. Compared to other ... also give you an estimate of the repair costs. Most of the time, shops do inspections for free.

Description : Where are portable screw compressors used?

Last Answer : Where are portable screw compressors used? The use of a portable screw air compressor in road, construction, mining and installation works indicates that its area of practical use is ... with these important, but fairly simple requirements will significantly lengthen the life of your compressor.

Description : How is silicone cookware used?

Last Answer : How is silicone cookware used? Every year silicone dishes are more and more popular among housewives, but the cost of such dishes is not high. Of course, not all dishes are made of ... counterfeits. Remember, real silicone cookware has no rubber smell and cannot cost less than a hundred rubles.

Description : List standard voltage level used in India. 

Last Answer : Standard voltage level used in India: * Generation Voltage : 3.3KV, 6.6KV,11KV and 17.5 KV,21KV (Now a days generation voltage is in the range of 11KV- 33KV) * Primary Transmission voltage :- 220 ... voltages in India are 765 KV (750KV), 400KV, 220KV, 132KV, 110KV, 66KV, 33KV, 22KV, 11KV.

Description : State the insulating materials used in motor. Write temperature class and withstand temperature ranges for them. 

Last Answer : The insulating materials used in motor are as belows: 1. Cotton, 2. Silk, or paper, 3. Press board, 4. Resins 5. PVC 6. Cellulose-Fiber, 7. Enameled coating, etc  ... Over 180° Mica, porcelain, ceramics, glass quartz, asbestos, treated glass fiber or treated asbestos. etc.

Description : Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.

Last Answer : Parts Insulating Materials  Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils.  ... Transformer bushings Porcelain  Insulation between transmission line and pole. Porcelain

Description : State the material used for making (1) Magnetic Core (2) Fuse element  

Last Answer : The material used for making of:  (1) Magnetic Core : Iron, cobalt, Nickel, CRGO, HRGO , silicon steel  (2) Fuse Element: Tin- lead wire, Tinned copper wire 

Description : State different types of holders used in wiring installation.

Last Answer : Following types of holders used in wiring installation: 1. Pendent Holder 2. Batten Holder 3. Angle holder 4. Screwed holder 

Description : List any four materials used for pattern making

Last Answer : The various types of materials used are as follows: 1. Wood 2. Metal. 3. Plastic. 4. Plaster. 5. Wax.

Description : List any four accessories used on lathe.

Last Answer : The various accessories used in lathe are as follows. 1) Lathe centers 2) Carriers or driving dog 3) catch plates 4) Chucks 5) Face plates 6) Angle plates 7) Mandrels 8) Rests

Description : State properties of conductor material used for overhead conductor. 

Last Answer : Following are the properties of conductor material:-   1. High conductivity :- Material should have high conductivity 2. High mechanical strength:- Material should have sufficiently high mechanical strength ... available & less costly. 9. Scrap Value: - Material should have high scrap value. 

Description : Enlist the luminaries used in factory lighting and lux level required in various areas.

Last Answer : Area Luminaries Lux level Office building Fluorescent tube, LED, CFL 500 lux Testing centre Fluorescent tube, LED, CFL 400 to 500 lux Workshop/work place Halogen ... , LED, CFL, Projector lamp, filament lamp, Halogen Lamp, Metal Halide lamp etc Above 600 Lux

Description : State the different types of outdoor flood lighting and where are they used.

Last Answer : There are three types of projectors used for flood lighting :  a) Narrow beam Projector b) Medium angle Projector c) Wide angle Projector a) Narrow beam Projectors: - Light beam with such ... yards, stadiums, car parking area etc. 3) It is used for illuminating advertisements, boarding's etc.

Description : State functions of ; i) Cable box ii) Guard wire iii) Shackle insulator iv) Stay wire used in service connection

Last Answer : i) Function of Cable box: To hold and inspect incoming and outgoing terminals  ii) Function of Guard wire : A grounded conductor placed beneath an overhead transmission line in order to ground ... in service connection: To give mechanical Support to pole, line and prevent leakage current if any

Description : State starters used for i) 3-Ph squirrel cage induction motor (3HP) ii) D.C. motor 

Last Answer : Name the starters used for following motors : i) 3 H.P. 3-Ph squirrel cage I.M: i) DOL starter OR ii) Star-Delta Starter OR ii) Auto transformer starter OR iii) Soft start starter.  ii) D.C Shunt Motor : 1) Armature resistance starter (Three Point Starter) OR 2) Four Point Starter 

Description : Give the classification of the errors used in measuring instrument & state the reason for their occurrence.

Last Answer : Types of errors in measuring instruments:  A) Gross error: These are due to mistakes on the part of person using the instrument.  B) Systematic Error:  i) Instrumental Error: These ... multiplying factor.  C) Random error: These persist even after gross and systematic errors are removed. 

Description : Name the material used for :- (i) Moving coil (ii) Permanent magnet in PMMC instrument.

Last Answer : (i) Material used for Moving coil: Copper, Aluminum( some times)  (ii) Permanent magnets are made of special alloys such as :  Aluminum-Nickel-Cobalt (Alnicos)  Strontium-Iron  Neodymium-Iron-Boron  Samarium-Cobalt.

Description : State the use of shunt and series resistance used in extension of meter.

Last Answer : Use of shunt and series resistance: i) Use of shunt: To extend the range of Ammeter. ii) Use of series resistance: To extend the range of Voltmeter.

Description : State the material used for moving coil and former for PMMC instruments. 

Last Answer : Material Used for Moving Coil and Former for PMMC Instruments:  Material used for moving coil: Copper  Material used for Former: Aluminium

Description : Why common emitter configuration is commonly used?

Last Answer : Common emitter configuration is commonly used for amplifications because 1. The common emitter configuration (CE) provides maximum voltage and current gain and hence provides maximum power gain. The ... automatic impedance matching maximum power transfer will take place from one stage to other.

Description : Which of the following device is used for coupling microwave energy?  A) Resonator B) Waveguide C) Loop D) Antenna

Last Answer : A

Description : Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO 

Last Answer : Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO 

Description : Permanent magnet moving coil instruments are used for

Last Answer : PMME are mostly used for measuring voltage and current.

Description : Light triggering is mainly used in

Last Answer : Light triggering is mainly used in High voltage direct current transmission

Description : Shunt compensation in an EHV line is used to (A) Improve stability. (B) Improve the voltage profile. (C) Reduce the fault level. (D) Substitute for synchronous phase modifier.

Last Answer : Shunt compensation in an EHV line is used to Improve the voltage profile.

Description : Taskbar is used for (A) Navigation program (B) Switching between program (C) Start a program (D) All of above

Last Answer : Taskbar is used for (A) Navigation program (B) Switching between program (C) Start a program (D) All of above

Description : Wave trap is used to trap waves of:  (A) Power frequencies (B) Higher frequencies entering generator or transformer units (C) All of the above (D) None of the above

Last Answer : Wave trap is used to trap waves of: Higher frequencies entering generator or transformer units

Description : A relay used for protection of motors against overload is :  (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay

Last Answer : D

Description : Earthing switch is used for?  (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above 

Last Answer : Earthing switch is used for?  (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above