IDMT relays are used to protect the transformer against : (A) Internal short -circuits (B) Open circuits (C) External short circuits (D) Oil leakage
Last Answer : IDMT relays are used to protect the transformer against : External short circuits
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3.1k views
1 answer
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Apr 30, 2018
by
anonymous

Last Answer : The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.
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2.6k views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The single phasing relays are used for the protection of three phase motors.
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300 views
1 answer
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Mar 20, 2018
by
anonymous

For a 500 Hz frequency excitation, a 50 km long power line will be modeled as
Last Answer : For a 500 Hz frequency excitation, a 50 km long power line will be modeled as long line
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2.8k views
1 answer
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Apr 29, 2018
by
anonymous

what is mean by long transmission line ?
Last Answer : The transmission line which have length more than 250 km are known as long transmission lines.
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88 views
1 answer
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Aug 18, 2017
by
anonymous

Last Answer : Large internal faults are protected by merz price percentage differential protection.
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154 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Reactance relay is preferred for phase fault on short transmission line.
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110 views
1 answer
asked
Mar 20, 2018
by
anonymous

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.
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96 views
1 answer
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Jan 2, 2021
by
anonymous

Last Answer : Discrimination between main and back up protection is provided by the use of relays which are slow.
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396 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : To protect most of the electrical equipment handling low power, the types of relays used are thermocouple, electronic and bimetallic.
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106 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Protective relays are devices that detect abnormal conditions in electrical circuits by measuring constantly the electrical quantities which differ during normal and abnormal conditions.
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132 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : Directional relays are based on flow of power.
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165 views
1 answer
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Mar 19, 2018
by
anonymous

D.C. shunt relays are made of?
Last Answer : D.C. shunt relays are made of many turns of thin wire.
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2.7k views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : Thermal overload relays are used to protect the motor against overcurrent due to heavy loads.
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254 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Overload relays are of induction, solid state, thermal, electromagnetic type.
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73 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Relays can be designed to respond to changes in resistance, reactance or impedance voltage and current, light intensity, temperature.
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145 views
1 answer
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Mar 19, 2018
by
anonymous

Write the relation between phase and line current, phase and line voltage for Star connection.
Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection
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381 views
2 answers
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Aug 11, 2018
by
anonymous

What is line voltage and phase voltage? Draw balanced three phase star connected system. Show all the voltages and currents.
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125 views
0 answers
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Aug 11, 2018
by
anonymous

For 11kV line the inductance per km per phase will be of the order of: (A) 1 H (B) 0.1 H (C) 1 mH (D) 0.1 mH
Last Answer : For 11kV line the inductance per km per phase will be of the order of: 1 mH
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1.0k views
1 answer
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May 8, 2018
by
anonymous

What is the difference between line and phase current?
Last Answer : The currents flows through phase lines is called line voltage and currents flows from phase to neutral line is called phase current
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132 views
1 answer
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Mar 10, 2018
by
anonymous

What is the difference between line and phase voltage?
Last Answer : Line voltage is voltage between two phases R &Y (415 v) while phase voltage is the voltage between one phase and a neutral B & N (240 v).
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207 views
1 answer
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Mar 10, 2018
by
anonymous

What is the voltage in 3 phase line?
Last Answer : between 430 to 440 v
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283 views
4 answers
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Dec 22, 2017
by
anonymous

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.
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5.3k views
1 answer
asked
May 8, 2018
by
anonymous

Series capacitive compensation in EHV transmission line is used to
Last Answer : To maintain voltage stability
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466 views
2 answers
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Apr 29, 2018
by
anonymous

The ALE line of an 8085 microprocessor is used to (A) latch the output of an I/O instruction into an external latch. (B) deactivate the chip-select signal from memory devices. (C) find the interrupt ... of the TRAP interrupt. (D) latch the 8 bits of address lines AD7-AD0 into an external latch.
Last Answer : The ALE line of an 8085 microprocessor is used to latch the 8 bits of address lines AD7-AD0 into an external latch.
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198 views
1 answer
asked
Apr 28, 2018
by
anonymous

Last Answer : Sandwich type winding is used in 3 phase shell-type transformer.
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197 views
1 answer
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Mar 19, 2018
by
anonymous

What are the five types of single phase motors used in the industry?
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79 views
0 answers
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Mar 15, 2018
by
anonymous

How many types of types of relays are there?
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50 views
0 answers
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Aug 17, 2019
by
anonymous

Consider the following statements. Which of these statements are correct ? (1) Reactance relays are preferred for ground fault relaying (2) Impedance relays are most suitable for:protecting long transmission lines (3) Mho relays are best ... (1) and (3) (C) (2) and (4) (D) (1), (2) and (4)
Last Answer : Consider the following statements. Which of these statements are correct ? (1) Reactance relays are preferred for ground fault relaying (2) Impedance relays are most suitable for:protecting long transmission lines (3) Mho relays are ... (1) and (3) (C) (2) and (4) (D) (1), (2) and (4)
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131 views
1 answer
asked
Apr 29, 2018
by
anonymous

Reactance relays are employed for Phase faults in : (A) Short lines (B) Medium lines (C) Long lines (D) Any line
Last Answer : Reactance relays are employed for Phase faults in : Short lines
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125 views
1 answer
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May 12, 2018
by
anonymous

The surge impedance for over head line is taken as (1) 10-20 ohms (2) 50-60 ohms (3) 100-200 ohms (4) 1000-2000 ohms
Last Answer : The surge impedance for over head line is taken as 100-200 ohms
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108 views
1 answer
asked
May 1, 2018
by
anonymous

A lightening arrester connected between the line and earth in a power system (1) protects the terminal equipment against travelling surges (2) protects the transmission line against direct ... suppresses high frequency oscillations in the line (4) reflects back the travelling wave approaching it
Last Answer : A lightening arrester connected between the line and earth in a power system protects the terminal equipment against travelling surges
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365 views
1 answer
asked
Apr 29, 2018
by
anonymous

The reactive power transfer over a line mainly depends on
Last Answer : The reactive power transfer over a line mainly depends on lVsl- lVRl
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411 views
1 answer
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Apr 27, 2018
by
anonymous

lf a travelling-wave travelling along a loss-less overhead line does not result in any reflection after it has reached the far end, then the far end of the line is
Last Answer : lf a travelling-wave travelling along a loss-less overhead line does not result in any reflection after it has reached the far end, then the far end of the line is terminated into a resistance equal to surge impedance of the line
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105 views
1 answer
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Apr 26, 2018
by
anonymous

Transmission efficiency of a transmission line increases with the
Last Answer : Transmission efficiency of a transmission line increases with the increase in power factor and voltage
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88 views
1 answer
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Apr 26, 2018
by
anonymous

Last Answer : The inductive interference between power and communication line can be minimized by transposition of the power line, transposition of the communication line.
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175 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : When a wave propagates on a transmission line, it suffers reflection several times at sending and other end.
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130 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : The interaction between a transmission line and communication line is minimized by transposing transmission as well as communication lines, increasing the height of the transmission line tower, increasing the distance between the two lines.
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168 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : When a transmission line is energized, the wave that propagates on it is current wave and voltage wave.
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125 views
1 answer
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Mar 20, 2018
by
anonymous

Last Answer : A transmission line is protected by distance protection, time graded and current graded overcurrent protection.
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82 views
1 answer
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Mar 19, 2018
by
anonymous

Why is AC better for long distance power transmission than DC ?
Last Answer : ac is more economical to transmit for long distances . wires can be made smaller by step up transformer .. since major cost are wires to transmit .. then at the end of distance step down transformer is used for commercial use.
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210 views
4 answers
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Aug 25, 2019
by
anonymous

The standard for long distance analog signal transmission in process control industry is (A) 4-20 mV (B) 0-20 mA (C) 4-20 mA (D) 0-5 V
Last Answer : The standard for long distance analog signal transmission in process control industry is 4-20 mA
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2.6k views
1 answer
asked
Apr 26, 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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102 views
1 answer
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Mar 22, 2018
by
anonymous

Last Answer : A cumulatively compounded long shunt generator when operating as a motor would be differentially compounded long shunt.
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111 views
1 answer
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Mar 21, 2018
by
anonymous

96 views
0 answers
asked
Jan 21, 2020
by
Shubham

relays are used for phase faults on long line. (a) Impedance (b) Reactance (c) Either of the above (d) None of the above
Last Answer : (a) Impedance
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30 views
1 answer

The sending end and receiving end voltages of a three-phase transmission line are 10 kV/ph and 9.5 kV/ph, respectively. If the resistance drop is 150 V/ph and receiving end power factor is 0.8, the sending end power factor is (A) 0.745 lagging (B) 0.775 lagging (C) 0.8 lagging (D) 0.85 lagging
Last Answer : Vscos¢s-Vrcos¢r=IR
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3.0k views
2 answers
asked
Apr 28, 2018
by
anonymous

Light triggering is mainly used in
Last Answer : Light triggering is mainly used in High voltage direct current transmission
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441 views
1 answer
asked
May 8, 2018
by
anonymous

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
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548 views
2 answers
asked
May 8, 2018
by
anonymous

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
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113 views
1 answer
asked
May 8, 2018
by
anonymous
