Last Answer : Natural oil cooling is used for transformers up to a rating of 3000 kVA.
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158 views
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Mar 19, 2018
by
anonymous

Last Answer : A common method of cooling a power transformer is oil cooling.
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156 views
1 answer
asked
Mar 19, 2018
by
anonymous

Why a transformer requires cooling. What are the methods of cooling transformers?
Last Answer : Ans. Transformers requires cooling as they get heated up due to various losses taking place in the transformer. (like iron of copper losses) Following are the methods of cooling of transformer. a. Natural ... . Forced oil air Natural Cooling (OFAN). d. Forced oil and forced Air cooling (OFAF).
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6 views
1 answer

Last Answer : Distribution transformers are generally designed for maximum efficiency around 50% load.
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142 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Power transformers are generally designed to have maximum efficiency around near full-load.
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107 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The rate of acceleration on suburban or urban services is restricted by the consideration of Passenger Discomfort.
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101 views
1 answer
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Mar 22, 2018
by
anonymous

Last Answer : Overload capacity of diesel engines is usually restricted to 2 percent.
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128 views
1 answer
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Mar 22, 2018
by
anonymous

Last Answer : Winding will be damaged
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135 views
2 answers
asked
Mar 19, 2018
by
anonymous

If the percentage impedances of the two transformers working in parallel are different, then?
Last Answer : If the percentage impedances of the two transformers working in parallel are different, then parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load.
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131 views
1 answer
asked
Mar 19, 2018
by
anonymous

Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in?
Last Answer : Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in loading of the transformers not in proportion to their kVA ratings.
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377 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Short circuit test on transformers is conducted to determine copper losses.
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218 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Necessary conditions required to be satisfied in order to ensure successful parallel operation of single phase transformers: 1. Only transformers having the same phase displacement between primary and secondary ... . 7. The phase sequence must be followed strictly on HV and LV side connection.
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197 views
2 answers
asked
Mar 19, 2018
by
anonymous
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Losses which occur in rotating electric machines and do not occur in transformers are?
Last Answer : Friction losses windage losses
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208 views
2 answers
asked
Mar 19, 2018
by
anonymous

The efficiency of two identical transformers under load conditions can be determined by?
Last Answer : The efficiency of two identical transformers under load conditions can be determined by back-to-back test.
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323 views
1 answer
asked
Mar 19, 2018
by
anonymous

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
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179 views
2 answers
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Mar 19, 2018
by
anonymous

Cooling Fans
Last Answer : Many notebook computer users think that the term "laptop" is a misnomer. After a few hours of use, a notebook computer can get a bit too hot, which makes it uncomfortable to operate on your lap. ... fan will not only keep your notebook in tip-top shape, but it will also make cooler heads prevail.
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7 views
1 answer
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May 5, 2021
by
anonymous

Draw and explain the function of cooling tower in TPS.
Last Answer : Cooling tower in TPS: The function of cooling tower is to reduce the temperature of water coming from condenser. Water is circulated from the basin of the cooling ... cooling Tower temperature of water is reduced either by natural or forced or induced draught method or combine
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108 views
1 answer
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Aug 2, 2019
by
anonymous

State the function of cooling tower and condenser in thermal power station.
Last Answer : 1. Condenser: Function of condenser is to convert exhaust steam again into water by reducing its temperature with the help of cold water. Also it reduces back pressure of steam turbine 2 ... tower : The function of cooling tower is to reduce the temperature of water coming from condenser.
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315 views
1 answer
asked
Sep 8, 2018
by
anonymous

Which of the following is used for thermoelectric cooling? A) Peltier effect B) Seebeck effect C) Both A and B D) None of these
Last Answer : Which of the following is used for thermoelectric cooling? A) Peltier effect B) Seebeck effect C) Both A and B D) None of these
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98 views
1 answer
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Apr 29, 2018
by
anonymous

74)Power transformers are generally designed to have maximum efficiency around A. No load B. Half load C. Near full load D. 10% overload
Last Answer : C. Near full load
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14 views
1 answer

Last Answer : Harmonics in transformer result in increased core losses, increased I2R losses, and magnetic interference with communication circuits.
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70 views
1 answer
asked
Mar 19, 2018
by
anonymous

[23] Transformers are rated in KVA instead of KW because A. load power factor is often not known B. KVA is fixed whereas KW depends on load power factor C. Total transformer loss depends on volt ampere D. It has become customary
Last Answer : C. Total transformer loss depends on volt ampere
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130 views
1 answer

TRANSFORMERS MCQ
Last Answer : 101. A shell-type transformer has (a) high eddy current losses (b) reduced magnetic leakage (c) negligibly hysteresis losses (d) none of the above Ans: b 102. A transformer can have regulation closer to zero (a ... (6) much smaller (c) much higher (d) somewhat smaller (e) none of the above Ans: c
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539 views
3 answers

What are the schedules of maintenance done on transformers?
Last Answer : Ans. Following are the schedules of maintenance on transformers. a. Daily maintenance. b. Monthly maintenance. c. Quarterly maintenance. d. Half yearly maintenance. e. Yearly maintenance. f. 5 Yearly maintenance.
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7 views
1 answer
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What are the loses in Transformers, Explain?
Last Answer : Ans. (1) Iron loses (2) Copper loses Iron Loss : Iron loss occurs in the transformers Iron core due to hysteresis and eddy currents taking place. They are almost fixed irrespective of ... losses in the primary and the secondary windings of the transformer which with the loading of transformer.
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3 views
1 answer

63 views
0 answers
asked
Aug 13, 2019
by
Alacrity

Classify the transformers based on the construction, frequency and power.
Last Answer : Classification of Transformer Based On: i) Construction: Shell type, Core type, Berry type ii) Change in voltage level: Step-Up, Step-Down, iii) Number of phases: Single phase, Three phase iv) ... Control vi) Cooling: Self-cooled, Air-cooled, Forced-air cooled, Oil-cooled, Forced-oil cooled.
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133 views
1 answer
asked
Aug 30, 2018
by
anonymous
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Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary
Last Answer : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary
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580 views
1 answer
asked
May 8, 2018
by
anonymous

Two transformers A and B having equal outputs and voltage ratios but unequal percentage impedances of 4 and 2 are operating in parallel. The transformer A will be overloaded by
Last Answer : Two transformers A and B having equal outputs and voltage ratios but unequal percentage impedances of 4 and 2 are operating in parallel. The transformer A will be overloaded by 33%
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672 views
1 answer
asked
May 8, 2018
by
anonymous

Core type transformers are popular in___________. (A) High voltage applications (B) Low voltage applications (C) All of the above (D) None of the above
Last Answer : Core type transformers are popular in High voltage applications
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96 views
1 answer
asked
May 8, 2018
by
anonymous

In a transmission line if booster transformers are to be used, preferred location will be (A) At the receiving end (B) At the sending end (C) At the intermediate point (D) Anywhere in the line
Last Answer : In a transmission line if booster transformers are to be used, preferred location will be At the intermediate point
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346 views
1 answer
asked
May 8, 2018
by
anonymous

The friction losses in Real Transformers are : (A) 0% (B) 5% (C) 25% (D) 50%
Last Answer : A
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3.3k views
2 answers
asked
May 8, 2018
by
anonymous

Two 3-phase transformers cannot be operated in parallel, if their : (A) kVAs are different (B) phase sequences are different (C) % impedances are different (D) voltage ratios are different
Last Answer : Two 3-phase transformers cannot be operated in parallel, if their : phase sequences are different
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151 views
1 answer
asked
Apr 30, 2018
by
anonymous

An additional condition for parallel operation of three-phase transformers over single-phase transformers is that
Last Answer : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that the transformers should belong to the same vector group
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144 views
1 answer
asked
Apr 29, 2018
by
anonymous

Which of the following is the advantage of using CRGO steel in transformers? A) High magnetic flux density B) Low permeability C) Both A and B D) None of these
Last Answer : It definitely High Magnetic Flux Density since a crgo steel has always a more around 3% of silicon proportion among the remaining ferrite which make cold rolled grain oriented steel having high flux magnetic ... for more about the crgo core you can learn here https://nicoreindia.com/crgo-core/
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153 views
2 answers
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Apr 29, 2018
by
anonymous

Last Answer : Instrument transformers are potential transformers, current transformers.
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84 views
1 answer
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Mar 21, 2018
by
anonymous
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What is the back EMF in Transformers?
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77 views
0 answers
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Mar 15, 2018
by
anonymous
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Last Answer : Current transformers (CT) : Current transformer (CT) actually step down the high current to low current for the operation of relays. Current transformer is use for measurement of ... use for relay. This is about potential transformer.
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137 views
1 answer
asked
Jan 15, 2018
by
James

Why do transformers make noise?
Last Answer : Transformers make noise based on it out put if an transformer outputs is 400v maximum than a 398v be apply to that transformer it also make a noise because of that
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91 views
1 answer
asked
Dec 17, 2017
by
anonymous

How to Build a Natural Gas Burnout Oven
Last Answer : How to Build a Natural Gas Burnout Oven How to Build a Natural Gas Burnout Oven Ever fancied making your own pizza or a homemade cake? Well, you can not only save big bucks but also make great baked ... the excess gas can escape. To do this try making a window on the top portion of the oven frame.
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6 views
1 answer
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May 12, 2021
by
anonymous

Natural Aspirin
Last Answer : To keep your diet high in natural salicylates (the main ingredient in aspirin that helps prevent heart attacks), eat more oranges, raspberries, apricots and cherries. For additional salicylates, season foods with cinnamon, curry, cayenne and thyme.
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1 answer
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May 4, 2021
by
anonymous

Best Natural Antioxidant Spice
Last Answer : Best Natural Antioxidant Spice - Cloves Researchers have identified cloves (Syzygium aromaticum) as the best natural antioxidant spice, because they contain high levels of phenolic compounds, as well as ... used in a Mediterranean diet . Flavour and Fragrance Journal 25, 13-19, February 2010.
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3 views
1 answer
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May 3, 2021
by
anonymous
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Organic Gardening Natural Gardening
Last Answer : Organic Gardening The Basics of Organic Gardening When we talk of organic gardening, some of us believe that it is a process where gardens are cultivated without the aid of synthetic chemicals to ... not only that, you also get to do your part in maintaining the balance of our environment.
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7 views
1 answer
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May 3, 2021
by
anonymous

How to choose high quality and natural dairy products?
Last Answer : Dairy products have always been the basis of nutrition, and this is quite justified: after all, they contain only natural substances that contribute to normal digestion. However, in an effort to reduce ... kilogram. Real sour cream will only be called sour cream, and butter will be called butter.
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5 views
1 answer
asked
Mar 29, 2021
by
anonymous

Differentiate between Natural and Forced commutation
Last Answer : Natural commutation Forced commutation Source is AC Source is DC External commutating componants are not required External commutating componants are required SCR turns off ... in controlled rectifiers, AC voltage controllers etc. Used in choppers & inverters etc
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1.8k views
1 answer
asked
Oct 13, 2019
by
anonymous

Define natural, mechanical, forced and induced draught systems.
Last Answer : Natural draught system: - When the fuel is burnt (combustion) in the furnace due to natural circulation of air, the draught is called natural draught. Mechanical draught system: - In a mechanical ... combustion. OR If fan/blower is placed after the furnace then it is called as induced draught
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91 views
1 answer
asked
Sep 7, 2018
by
anonymous

An accelerometer has input range of 0 to 10g, natural frequency 30 Hz and mass 0.001 kg. The range of the secondary displacement transducer in mm required to cover the input range is (A) 0 to 2.76 (B) 0 to 9.81 (C) 0 to 11.20 (D) 0 to 52.10
Last Answer : An accelerometer has input range of 0 to 10g, natural frequency 30 Hz and mass 0.001 kg. The range of the secondary displacement transducer in mm required to cover the input range is 0 to 2.76
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72 views
1 answer
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Apr 26, 2018
by
anonymous

Last Answer : Natural commutation is also called as line Communication. The turning off of thyristor due to AC supply is called natural commutation or line commutation. If the thyristor is connected to AC supply ... connected to positive and anode terminal get connected to negative, this turns off the thyristor.
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108 views
1 answer
asked
Sep 21, 2017
by
anonymous

What happens when you converts two isotopic versions of a metal into a plasma and then cool them down?
Last Answer : Let me ask you a question. If you add hydrogen gas to a room, where does it collect? It depends on the metal and method. I’ve heard of using induction of a plasma state along with a centrifugal system, but isotopes and inorganic chem isn’t really my thing.
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2 views
1 answer
asked
Mar 2
by
anonymous

What comes naturally to you that doesn't come naturally to everyone?
Last Answer : Common sense, apparently.
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1 view
1 answer
asked
Mar 2
by
anonymous
