Losses which occur in rotating electric machines and do not occur in transformers are?
Last Answer : Friction losses windage losses
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211 views
2 answers
asked
Mar 19, 2018
by
anonymous

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
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77 views
1 answer
asked
Aug 17, 2019
by
anonymous

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.
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95 views
1 answer
asked
Aug 17, 2019
by
anonymous

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

Last Answer : The standard full-load power factor ratings for synchronous motors are unity or 0.8 leading.
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99 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : For power factor correction, synchronous motors operate at no-load and greatly over-excited fields.
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110 views
1 answer
asked
Mar 20, 2018
by
anonymous

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

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

Last Answer : Winding will be damaged
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138 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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135 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : Distribution transformers are generally designed for maximum efficiency around 50% load.
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144 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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381 views
1 answer
asked
Mar 19, 2018
by
anonymous

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

Last Answer : Natural air cooling is generally restricted for transformers up to 1.5 MVA .
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191 views
1 answer
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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325 views
1 answer
asked
Mar 19, 2018
by
anonymous
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Electric Power
Last Answer : Electric Power
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95 views
1 answer
asked
Apr 8, 2020
by
anonymous

State elements of diesel electric power plant with their functions.
Last Answer : Elements of Diesel Power Plant with their function): 1) Diesel Engine: - This is the main component of the P.P. which develops mechanical power. 2) Engine air intake system: - Air ... fuel as per requirement. 10) Alternator: - Its function is to convert mechanical power into electrical power.
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100 views
1 answer
asked
Aug 2, 2019
by
anonymous

Options: A) WATT B) AMPERE C) VOLTS D) OHM
Last Answer : Correct Answer: A) WATT
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76 views
1 answer
asked
Jun 28, 2019
by
anonymous

Electric power formula
Last Answer : Electric power formula
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65 views
1 answer
asked
Jun 11, 2019
by
anonymous
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"Hydro electric power station are not perennial power station". Justify.
Last Answer : Justification: The water utilized by the hydro power plants comes mostly from storage dams/reservoirs which get filled up during the monsoon rainy season. Such reservoirs are utilized for supplying ... are important. Hence "Hydro electric power stations are not perennial power station"
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92 views
1 answer
asked
Sep 8, 2018
by
anonymous

Explain starting system in diesel electric power plant.
Last Answer : Starting system in Diesel Electric Power Plant: It includes Storage battery, compressed air tanks, self-starter etc. The purpose of engine starting system is to rotate the engine initially while ... as Ammeters, Voltmeters, Wattmeters, Thermometers, Pressure gauges, Visible and audible alarm etc.
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130 views
1 answer
asked
Sep 8, 2018
by
anonymous

Explain fuel system and air intake system in diesel electric power plant.
Last Answer : Fuel system and air intake system in diesel electric power plant : Fuel system: It consists of storage tank, strainers, fuel transfer pump and all day fuel tank. The fuel oil is supplied ... Filters are provided to remove dust particles from air which may act as abrasive in the engine cylinder.
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125 views
1 answer
asked
Sep 8, 2018
by
anonymous

State any four advantages and four disadvantages of diesel electric power plant.
Last Answer : Advantages of Diesel electric power plant:- 1) The design and layout of Diesel electric power plant is simple. 2) It requires less space. 3) Time required for complete erection of diesel power plant is less ... . 9) The useful life is very short. 10) Availability of fuel in future may be limited.
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125 views
1 answer
asked
Sep 7, 2018
by
anonymous

List out the four applications of diesel electric power plant.
Last Answer : Applications of Diesel Power Plant: 1. It can be used as a standby (emergency) power plant to maintain continuity of supply. (Incase failure of main supply like hospital, Telephone exchange Radio stations, ... 10. Diesel plants are widely used for generating power ranging from 100 to 5,000 H.P.
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169 views
1 answer
asked
Sep 7, 2018
by
anonymous

An _____________is a network of electrical components used to supply, transfer and use electric power: (A) Electric power system (B) Electric power (C) All of the above (D) None of the above
Last Answer : An Electric power system is a network of electrical components used to supply, transfer and use electric power.
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94 views
1 answer
asked
May 8, 2018
by
anonymous

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
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107 views
1 answer
asked
Apr 29, 2018
by
anonymous

Power factor of electric bulb is?
Last Answer : Power factor of electric bulb is unity.
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93 views
1 answer
asked
Mar 25, 2018
by
anonymous

Last Answer : Power for lighting in passanger coach, in a long distance electric train, is provided through individual generator of bogie and batteries.
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103 views
1 answer
asked
Mar 22, 2018
by
anonymous

Last Answer : In a steam locomotive electric power is provided through small turbo-generator.
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78 views
1 answer
asked
Mar 22, 2018
by
anonymous

Last Answer : The power mentioned on the name plate of an electric motor indicates the output power available at the shaft.
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97 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : By use of thermocouple.
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215 views
2 answers
asked
Mar 20, 2018
by
anonymous

What is electric power generation transmission and distribution?
Last Answer : Generation: it wrong word at here.because it is no generation it is conversion of one form of energy into electrical form.it may by using any type of energy. Transmission is just to ... place to other by providing some modifications And distribution means use of this energy for any purpose.
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216 views
1 answer
asked
Dec 16, 2017
by
anonymous

what are the three different types of Electric power?
Last Answer : Real,reactive,apparent power
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126 views
2 answers
asked
Dec 4, 2017
by
anonymous
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Choose the correct order of electric discharge lamps in their increasing order of efficiencies (lumens/watt) : (A) Sodium vapour lamp, Mercury vapour lamp, Neon lamp (B) Neon lamp, Sodium vapour ... Mercury vapour lamp, Sodium vapour lamp (D) Mercury vapour lamp, Sodium vapour lamp, Neon lamp
Last Answer : Choose the correct order of electric discharge lamps in their increasing order of efficiencies (lumens/watt) : (A) Sodium vapour lamp, Mercury vapour lamp, Neon lamp (B) Neon lamp, Sodium ... Mercury vapour lamp, Sodium vapour lamp (D) Mercury vapour lamp, Sodium vapour lamp, Neon lamp
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95 views
1 answer
asked
Apr 30, 2018
by
anonymous

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

[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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132 views
1 answer

3 phase motor 42 hp same ratting two motors but pole change 2 and 4 pole tell me difference amp of both motors
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2.6k views
0 answers
asked
Jul 24, 2019
by
ZAHID

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

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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547 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

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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7 views
1 answer

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

66 views
0 answers
asked
Aug 13, 2019
by
Alacrity

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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587 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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686 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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99 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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348 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
