Copper, even though costly, finds use in the windings of electrical machines because

by

1 Answer

Answer :

Copper, even though costly, finds use in the windings of electrical machines because copper points offer low contact resistance , copper can be easily soldered and welded, copper windings are less bulky and the machines become compact.

by

Related questions

is universally used for windings of electrical machines because it is easily workable without any possibility of fracture. (a) Silver (b) Steel (c) Aluminium (d) Copper

Description : is universally used for windings of electrical machines because it is easily workable without any possibility of fracture. (a) Silver (b) Steel (c) Aluminium (d) Copper

Last Answer : (d) Copper

Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. lowers the insulation value and is a common cause of fault grounds in idle machines C. will enhance insulation resistance only if it is fresh water and contains no salt D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Description : Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ________. A. is good for long term preserving since most insulation is organic and contains some amount B. ... D. reduces the amount of current supplied or drawn by the machine so horsepower is limited

Last Answer : Answer: B

Though kinetics of ammonia synthesis dictates the use of low temperature for high equilibrium conversion, yet it is kept moderately high (550°C), because at low temperature (A) Rate of reaction is very low (B) Very high pressure is required resulting in costly pressure vessel (C) Space velocity of gas is very low resulting in decreased conversion (D) None of these

Description : Though kinetics of ammonia synthesis dictates the use of low temperature for high equilibrium conversion, yet it is kept moderately high (550°C), because at low temperature (A) Rate of reaction is very low ... (C) Space velocity of gas is very low resulting in decreased conversion (D) None of these

Last Answer : (A) Rate of reaction is very low

Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test, because the ___________. A. static charge of the machine may give a false reading B. armature will have a greater number of leakage paths C. insulation may be damaged D. insulation may be covered with moisture

Description : Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test, because the ___________. A. static charge of the machine ... number of leakage paths C. insulation may be damaged D. insulation may be covered with moisture

Last Answer : Answer: A

In dc machines, the armature windings are placed on the rotor because of the necessity for

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

The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength of the insulation B. the paint dust is composed of abrasive and semi-conducting materials which impair insulation C. paint dust buildup has a tendency to cause corrosion D. phase windings frequently become isolated from each other due to dust interference at the terminals

Description : The removal of paint from electrical equipment, such as generators, should be cautiously undertaken because ____________. A. the mechanical shock of paint removal lessens the dielectric strength ... phase windings frequently become isolated from each other due to dust interference at the terminals

Last Answer : Answer: B

______ is a branch of computer science which deals with helping machines finds solutions to complex problems in a more human like fashions A. Artificial Intelligence B. Internet of Things C. Embedded System D. Cyber Security

Description : ______ is a branch of computer science which deals with helping machines finds solutions to complex problems in a more human like fashions A. Artificial Intelligence B. Internet of Things C. Embedded System D. Cyber Security

Last Answer : A. Artificial Intelligence 

Though local search algorithms are not systematic, key advantages would include __________ a) Less memory b) More time c) Finds a solution in large infinite space d) Less memory & Finds a solution in large infinite space

Description : Though local search algorithms are not systematic, key advantages would include __________ a) Less memory b) More time c) Finds a solution in large infinite space d) Less memory & Finds a solution in large infinite space

Last Answer : d) Less memory & Finds a solution in large infinite space

Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test as the ______________. A. insulation may be damaged B. insulation may be covered with moisture C. armature windings will have a greater number of leakage paths D. larger machines may acquire a charge of static electricity during operation

Description : Before testing insulation with a megohmmeter, the windings of large machines should be grounded for about 15 minutes just prior to the test as the ______________. A. insulation may be damaged ... number of leakage paths D. larger machines may acquire a charge of static electricity during operation

Last Answer : Answer: D

Fractional pitch windings are used in DC machines to

Description : Fractional pitch windings are used in DC machines to (A) Reduce copper losses (B) Improve cooling (C) Increase the generated emf (D) Reduce sparking

Last Answer : Fractional pitch windings are used in DC machines to Reduce sparking

In an alternating current electrical system, a low system power factor is a direct sign of _____________. A. wasted energy B. efficient operation C. a short in the exciter field windings D. an excessive number of minor system grounds

Description : In an alternating current electrical system, a low system power factor is a direct sign of _____________. A. wasted energy B. efficient operation C. a short in the exciter field windings D. an excessive number of minor system grounds

Last Answer : Answer: A

The illustrated motor fails to start and gives a loud hum when the start button is depressed, your first action should be to __________. EL-0007 A. disassemble the motor to fix the centrifical switch so the start windings will be energized B. push the stop button to deenergize the 'M' coil C. reset the thermal overload D. hold the 'M' contactor closed by hand while wearing electrical safety gloves to get motor started

Description : The illustrated motor fails to start and gives a loud hum when the start button is depressed, your first action should be to __________. EL-0007 A. disassemble the motor to fix the centrifical ... D. hold the 'M' contactor closed by hand while wearing electrical safety gloves to get motor started

Last Answer : Answer: B

To repair a small electrical motor that has been submerged in saltwater, you should _____________. A. wash it with fresh water and apply an external source of heat B. renew the windings C. send it ashore to an approved service facility D. rinse all electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air

Description : To repair a small electrical motor that has been submerged in saltwater, you should _____________. A. wash it with fresh water and apply an external source of heat B. renew the windings ... electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air

Last Answer : Answer: A

The greatest detrimental effect on idle electrical equipment, such as cargo pump motors, is the _____________. A. loss of residual magnetism B. absorption of moisture in the insulation C. insulation varnish flaking D. dirt collecting on the windings

Description : The greatest detrimental effect on idle electrical equipment, such as cargo pump motors, is the _____________. A. loss of residual magnetism B. absorption of moisture in the insulation C. insulation varnish flaking D. dirt collecting on the windings

Last Answer : Answer: B

Electrical fault between two windings of same phase of a generator having double star winding can be

Description : Electrical fault between two windings of same phase of a generator having double star winding can be detected by the following protection in a generator:

Last Answer : Electrical fault between two windings of same phase of a generator having double star winding can be detected by the following protection in a generator: inter turn fault protection

A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of

Description : A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop  (A) starting torque (B) synchronizing torque (C) hysteresis torque (D) reluctance torque

Last Answer : A rotating electrical machine its self-inductances of both the stator and the rotor windings, independent of the rotor position will be definitely not develop synchronizing torque

21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Description : 21.The ordinary two winding transformer's primary and secondary windings always have A. different no of turns B. same size of copper wire C. a common magnetic circuit D. separate magnetic circuits

Last Answer : C. A common magnetic circuit

The weight of copper of both armature and field windings decreases with _____ in number of poles. (a) increase (b) decrease (c) either of the above (d) none of the above

Description : The weight of copper of both armature and field windings decreases with _____ in number of poles. (a) increase (b) decrease (c) either of the above (d) none of the above

Last Answer : (a) increase

Silicon steel is used in electrical machines because it has?

Description : Silicon steel is used in electrical machines because it has?

Last Answer : Silicon steel is used in electrical machines because it has low hysteresis loss.

Addition of 0.3 to 4.5% silicon to iron _____ the electrical resistivity of iron.

Last Answer : Addition of 0.3 to 4.5% silicon to iron increases the electrical resistivity of iron.

If a copper disc is rotated rapidly below a freely suspended magnetic...

Description : If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity

Last Answer : If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity less than that of disc and in the same direction.

Presence of even very minute amount (say 0.1%) of __________ in copper, reduces its electrical conductivity very seriously. (A) Bismuth (B) Arsenic (C) Antimony (D) Both (B) and (C)

Description : Presence of even very minute amount (say 0.1%) of __________ in copper, reduces its electrical conductivity very seriously. (A) Bismuth (B) Arsenic (C) Antimony (D) Both (B) and (C)

Last Answer : (D) Both (B) and (C)

The Himalayan region is poor in mineral resources because (a) it is made up of crystalline rocks (b) displacement of rock strata has disturbed the arrangement of rocks and made it complex (c) the climatic conditions are not suitable for exploitation of minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties

Description : The Himalayan region is poor in mineral resources because (a) it is made up of crystalline rocks (b) displacement of rock strata has disturbed the arrangement of rocks and made it ... minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties

Last Answer : Ans: (b)

The Himalayan region is poor in mineral resources because: [IAS 2004] (a) it is made of crystalline rocks (b) the displacement of rock strata has disturbed the arrangement of rock and made it complex (c) the climatic conditions are not suitable for exploitation of minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties

Description : The Himalayan region is poor in mineral resources because: [IAS 2004] (a) it is made of crystalline rocks (b) the displacement of rock strata has disturbed the arrangement of rock and ... minerals (d) the terrain makes exploitation of minerals difficult and very costly due to transport difficulties

Last Answer : Ans: (b)

Binary communications systems are better because A. they can interface directly with the analog telephone network B. the components are simpler, less costly, and more reliable C. people think better in binary D. interstate calls are less costly

Description : Binary communications systems are better because A. they can interface directly with the analog telephone network B. the components are simpler, less costly, and more reliable C. people think better in binary D. interstate calls are less costly

Last Answer : B. the components are simpler, less costly, and more reliable

Lead alone is not used in storing equipment, because it (A) Is very costly (B) Corrodes easily (C) Is having low creep strength (D) None of these

Description : Lead alone is not used in storing equipment, because it (A) Is very costly (B) Corrodes easily (C) Is having low creep strength (D) None of these

Last Answer : (C) Is having low creep strength

Double pipe heat exchangers are used (A) When heat transfer area required is very high (B) When heat transfer area required is very low, i.e. (100-200 ft 2 ). (C) Because it occupies less floor area (D) Because it is less costly

Description : Double pipe heat exchangers are used (A) When heat transfer area required is very high (B) When heat transfer area required is very low, i.e. (100-200 ft 2 ). (C) Because it occupies less floor area (D) Because it is less costly

Last Answer : (B) When heat transfer area required is very low, i.e. (100-200 ft 2 )

The synchronous modems are more costly than the asynchronous modems because a. they produce large volume of data b. they contain clock recovery circuits c. they transmit the data with stop and start bits d. they operate with a larger bandwidth e. none of above

Description : The synchronous modems are more costly than the asynchronous modems because a. they produce large volume of data b. they contain clock recovery circuits c. they transmit the data with stop and start bits d. they operate with a larger bandwidth e. none of above

Last Answer : they contain clock recovery circuits

Liquid ammonia is not used as such a fertiliser in tropical countries like India, because (A) Its N2 content is very low (B) It is very costly (C) It will evaporate on spraying (D) It is not available

Description : Liquid ammonia is not used as such a fertiliser in tropical countries like India, because (A) Its N2 content is very low (B) It is very costly (C) It will evaporate on spraying (D) It is not available

Last Answer : (C) It will evaporate on spraying

Granite is not suitable for ordinary building purpose because (A) It cannot be polished (B) It is not a fire proof material (C) It is costly (D) It has less crushing strength

Description : Granite is not suitable for ordinary building purpose because (A) It cannot be polished (B) It is not a fire proof material (C) It is costly (D) It has less crushing strength

Last Answer : Answer: Option C

TV is superior to radio as teaching aid because it (a) is costly (b) Invites two senses - hearing and vision simultaneously leading to more accurate form of learning (c) Is generally liked by pupils (d) all of the above

Description : TV is superior to radio as teaching aid because it (a) is costly (b) Invites two senses - hearing and vision simultaneously leading to more accurate form of learning (c) Is generally liked by pupils (d) all of the above

Last Answer : (b) Invites two senses - hearing and vision simultaneously leading to more accurate form of learning

Granite is not suitable for ordinary building purpose because a) It cannot be polished b) It is not fireproof c) It is costly*

Description : Granite is not suitable for ordinary building purpose because a) It cannot be polished b) It is not fireproof c) It is costly*

Last Answer : c) It is costly*

TV is superior to radio as teaching aid because it Options: A) is costly B) invites two senses hearing and vision simultaneously leading to more accurate form of learning C) is generally liked by pupils D) all of above

Description : TV is superior to radio as teaching aid because it Options: A) is costly B) invites two senses hearing and vision simultaneously leading to more accurate form of learning C) is generally liked by pupils D) all of above

Last Answer : B) invites two senses hearing and vision simultaneously leading to more accurate form of learning

Would you say that some people never obtain wealth even though they desire it, is because they can never imagine they can achieve it?

Description : Would you say that some people never obtain wealth even though they desire it, is because they can never imagine they can achieve it?

Last Answer : Yes. If you think you can you might. If you think you can’t you’re right.

What don't you do because of the price even though you can afford it?

Description : What don't you do because of the price even though you can afford it?

Last Answer : Buy KFC.

I really like a guy but can't date him because he lives out of state. Should I still accept dates from other guys even though I know I like someone else?

Description : I really like a guy but can't date him because he lives out of state. Should I still accept dates from other guys even though I know I like someone else?

Last Answer : If you can’t date him, your best bet is to get over him quickly. You won’t help yourself or him if you keep on pining over him. There are millions of eligible men out there; date other men.

can a employer hire u then say they dont want u because u are in a relationship with somebody in a similar profession.even though they knew it at the time of hiring.?

Description : can a employer hire u then say they dont want u because u are in a relationship with somebody in a similar profession.even though they knew it at the time of hiring.?

Last Answer : An employer is under no obligation to give you work even if you were promised it. The only way you will have any recourse is if you have a written contract, and the contract was breached.

Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Description : Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Last Answer : (B) High pressure drop of the gas

The large dark patches on the Moon’s surface are known as------? A. Dark matter B. Maria, or seas, even though there is no water on the Moon (Answer) C. Maria, or seas, because they are filled with water

Description : The large dark patches on the Moon’s surface are known as------? A. Dark matter B. Maria, or seas, even though there is no water on the Moon (Answer) C. Maria, or seas, because they are filled with water

Last Answer : B. Maria, or seas, even though there is no water on the Moon (Answer)

Copper wires are generally used for electrical power transmission instead of iron wire because (1) copper is cheaper than iron (2) copper is lighter than iron (3) copper is a better conductor of electricity than iron (4) copper can take higher power than iron

Description : Copper wires are generally used for electrical power transmission instead of iron wire because (1) copper is cheaper than iron (2) copper is lighter than iron (3) copper is a better conductor of electricity than iron (4) copper can take higher power than iron

Last Answer : (3) copper is a better conductor of electricity than iron Explanation: Copper is generally preferred for electrical power transmission instead of iron because of its high electrical conductivity and low resistivity.

Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Description : Copper is often used as an electrical conductor because it _______________. A. has high resistance at low temperatures B. has a highly polished surface C. is able to pass current with little opposition D. holds insulation together well

Last Answer : Answer: C

Copper wires are generally used for electrical power transmission instead of iron wire because : (1) copper is cheaper than iron (2) copper is lighter than iron (3) copper is a better conductor of electricity than iron (4) copper can take higher power than iron

Description : Copper wires are generally used for electrical power transmission instead of iron wire because : (1) copper is cheaper than iron (2) copper is lighter than iron (3) copper is a better conductor of electricity than iron (4) copper can take higher power than iron 

Last Answer : copper is a better conductor of electricity than iron

One finds it more difficult to walk on ice than on a concrete road because (a) ice is soft and spongy whereas concrete is hard (b) the friction between the ice and the feet is less than that between the concrete and the feet (c) there is more friction on ice than on concrete (d) it is not true

Description : One finds it more difficult to walk on ice than on a concrete road because (a) ice is soft and spongy whereas concrete is hard (b) the friction between the ice and the feet is less than that between the concrete and the feet (c) there is more friction on ice than on concrete (d) it is not true

Last Answer : Ans:(b)

Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because?

Last Answer : Two-value capacitor motor finds increased application as compressor motor in small home air-conditioners because it has low starting as well as running currents at relatively high power factor.

Which of the following alloy steels has the energy saving properties making it suitable for use in electrical machines? (A) Silicon steel (B) Chromium steel (C) Molybdenum steel (D) None of these

Description : Which of the following alloy steels has the energy saving properties making it suitable for use in electrical machines? (A) Silicon steel (B) Chromium steel (C) Molybdenum steel (D) None of these

Last Answer : (A) Silicon steel

Name power loses in rotating electrical machines.

Description : Name power loses in rotating electrical machines.

Last Answer : A: Power losess in rotating electrical machines are Copper losses, core losses, mechanical losses and stray losses.

Why the range of efficiency in transformers higher than those of other electrical machines?

Description : Why the range of efficiency in transformers higher than those of other electrical machines?

Last Answer : Transformers operate at higher efficiency when compared to other electrical machines.This is due to the absence of mechanical losses which is due to the absence of moving parts

What is the classification of duty of rotating electrical machines?

Description : What is the classification of duty of rotating electrical machines?  

Last Answer : S1 - Continuous operation at rated load (MCR) in 40 °C S2 - Short time operation (STR) for 5 minute or 15 minutes or 30 minutes. S3 - Intermittent periodic operation (resting and loading e.g. ... As for S3 but with starting S5 - As for S3 with electric braking S6 - Continuous cyclic operation. 

Which of the following is not a source of ozone emission in the atmosphere? (A) Refrigerators (B) Xerox machines (C) Dermatological photo-therapy equipments (D) High voltage electrical equipments

Description : Which of the following is not a source of ozone emission in the atmosphere? (A) Refrigerators (B) Xerox machines (C) Dermatological photo-therapy equipments (D) High voltage electrical equipments

Last Answer : (A) Refrigerators