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

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

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
Show More
3.1k views
1 answer
asked
Apr 30, 2018
by
anonymous

Last Answer : Impedance relays are used for phase faults on long line.
Show More
82 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
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
Show More
547 views
2 answers
asked
May 8, 2018
by
anonymous

A negative sequence relay is used for protection of (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines
Last Answer : A negative sequence relay is used for protection of Generator
Show More
627 views
1 answer
asked
May 1, 2018
by
anonymous

Surge absorbers are used for protection against
Last Answer : Surge absorbers are used for protection against low voltage high frequency oscillations
Show More
3.0k views
1 answer
asked
Apr 26, 2018
by
anonymous

With the help of neat diagram, describe the procedure to carry out phasing out test on a 3 phase transformer. Also state the purpose of conducting this test on 3 phase transformer.
Last Answer : i) This test is carried out on 3-ph transformer to identify primary & secondary winding belonging to the same phase. ii) As shown in fig above all primary & secondary phases ... of this test is to check the respective phases of primary & secondary windings in 3-ph transformer
Show More
292 views
1 answer
asked
Apr 27, 2020
by
anonymous

Why phasing out and polarity test is carried out on three phase transformer?
Last Answer : The phasing out test is carried out to identify the windings (primary and secondary) of corresponding phase of the three phase transformer. The polarity test is carried out to identify the ... identical polarity of the primary and secondary windings of each phase of the three phase transformer.
Show More
418 views
1 answer
asked
Jul 27, 2019
by
anonymous

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

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

Last Answer : Overload relays are of induction, solid state, thermal, electromagnetic type.
Show More
72 views
1 answer
asked
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.
Show More
145 views
1 answer
asked
Mar 19, 2018
by
anonymous

Describe different RT level computational and sequential components used to design single function processors.
Last Answer : RT-level combinational components:- To reduce the complexity in digital logic, combinational components are used, which are more powerful than logic gates. Such combinational ... during a clock edge. An asynchronous inputs value effects the circuit independent of the clock.
Show More
243 views
1 answer
asked
Mar 21, 2018
by
anonymous

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

How many types of types of relays are there?
Show More
50 views
0 answers
asked
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)
Show More
129 views
1 answer
asked
Apr 29, 2018
by
anonymous

Blind spot is a point in the zones of protection where
Last Answer : Blind spot is a point in the zones of protection where No protection is available.
Show More
665 views
1 answer
asked
May 8, 2018
by
anonymous

For protection of rotating machines against lightning surges _______ is used. (1) lightning arrester (2) capacitor (3) combination of lightning arrester and capacitor (4) lightning conductor and arrester
Last Answer : For protection of rotating machines against lightning surges combination of lightning arrester and capacitor is used.
Show More
4.5k views
1 answer
asked
Apr 30, 2018
by
anonymous

Reactance relay is normally preferred for protection against
Last Answer : Reactance relay is normally preferred for protection against earth faults
Show More
120 views
1 answer
asked
Apr 29, 2018
by
anonymous

Last Answer : Protection by fuses is generally not used beyond 100 A .
Show More
173 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
Last Answer : A fuse in a motor circuit provides protection against short-circuit and overload.
Show More
157 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
Last Answer : Overfluxing protection is recommended for generator transformer of the power plant.
Show More
79 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.
Show More
98 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : For the protection of power station buildings against direct strokes the requirements are interception, conduction and dissipation.
Show More
94 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : The delay fuses are used for the protection of motors.
Show More
101 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : A thermal protection switch can protect against overload.
Show More
233 views
1 answer
asked
Mar 19, 2018
by
anonymous

Primary and Backup Protection
Last Answer : Primary and Backup Protection B,D,G,I are the primary protection. A,C,H,J are the backup protection. About 90% of faults are clear by Primary Protection. So ... ordinated backup (primary is at various station and backup is at control room with computer)
Show More
401 views
1 answer
asked
Aug 9, 2017
by
anonymous
.jpg)
The single phasing relays are used for the protection of (a) single phase motors only (b) two phase motors only (c) two single phase motors running in parallel (d) three phase motors
Last Answer : (d) three phase motors
Show More
8 views
1 answer

Last Answer : In a single bus-bar system there will be complete shut down when fault occurs on the bus itself.
Show More
112 views
1 answer
asked
Mar 20, 2018
by
anonymous

Can anyone recommend a good, durable protection case for iPod Touch 4th gen?
Last Answer : I would highly recommend an Otterbox case. I have the Defender series case for my 3gen iPod touch. It's not perfect, but it provides better protection than any other case I've seen, and I like the ... ago, but that was only because I dropped my iPod and the case cracked. The ipod was fine though.
Show More
5 views
1 answer
asked
Feb 27
by
anonymous

What is the purpose of Overload Protection in a motor circuit?
Last Answer : Ans. The Overload Protection is used in a motor circuit to protect it from sustained over currents.
Show More
54 views
1 answer

Protection scheme for internal faults in a three phase star delta connected transformer
Show More
2 views
0 answers

Limitations of differential protection scheme of the altanetor
Show More
11 views
0 answers

Car Leather Protection
Last Answer : Your girlfriend and your leather car interior have many things in common. Both are tough but incredibly sensitive. Both are cold and are very hard to please. Both need a lot of attention and ... differences too. Unlike your girlfriend, leather is not something you want to get down and dirty with.
Show More
10 views
1 answer

3 phase 11KV to 4 10000 KVA alternator has neutral Earth through a resistance of 1 ohm the machine has current balance protection while operate upon of balance Karan exceed 18% of full load determine percentage of winding and protected against ground fault
Show More
25 views
0 answers

Explain in detail over-voltage protection.
Last Answer : Over-voltage protection: Over-voltage protection to the thyristor is provided using: i) R-C Snubber circuit ii) Non-linear resistor Thyrector A) Snubber Circuit: It is basically a ... returns to its high resistance state. Thyrector is normally placed across the supply terminals.
Show More
2.6k views
1 answer
asked
Jul 25, 2019
by
anonymous

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

Auto reclosing is used in case of
Last Answer : Auto reclosing is used in case of air blast C.B.
Show More
95 views
1 answer
asked
May 3, 2018
by
anonymous

The material used in liquid fuses is (1) SF6 (3) carbon tetra chloride (2) distilled water (4) transformer oil
Last Answer : The material used in liquid fuses is carbon tetra chloride
Show More
392 views
1 answer
asked
Apr 30, 2018
by
anonymous

Series reactors are used to
Last Answer : Series reactors are used to bring down the fault level within the capacity of the switchgear
Show More
77 views
1 answer
asked
Apr 26, 2018
by
anonymous
.jpg)
ln a minimum oil circuit breaker the oil is used
Last Answer : ln a minimum oil circuit breaker the oil is used to act as circuit breaking medium only
Show More
83 views
1 answer
asked
Apr 26, 2018
by
anonymous
.jpg)
Regulating-transformers are used in power systems for control of
Last Answer : Regulating-transformers are used in power systems for control of power flow
Show More
149 views
1 answer
asked
Apr 26, 2018
by
anonymous

Last Answer : A switchgear is device used for switching, controlling and protecting the electrical circuit and equipment.
Show More
258 views
1 answer
asked
Mar 20, 2018
by
anonymous
.jpg)
Last Answer : The material used for fuse must have low melting point and high specific resistance.
Show More
162 views
1 answer
asked
Mar 20, 2018
by
anonymous

Last Answer : Series capacitors are used to compensate for line inductive reactance.
Show More
77 views
1 answer
asked
Mar 20, 2018
by
anonymous
