# If a relay fails to operate for a fault within its reach, it is said to

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If a relay fails to operate for a fault within its reach, it is said to

## 1 Answer

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If a relay fails to operate for a fault within its reach, it is said to Under reach

## Related questions

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A series generator is supplying power to DC bus bar. If the prime mover fails, then the machine will operate as (A) DC series motor rotating in the same direction (B) DC series motor rotating in the opposite direction (C) DC series generator rotating in the same direction (D) Machine will stop

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If the fault current is 6000 A, the relay plug setting is 150% and the CT ratio is 400/5, the plug setting multiplier will be

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A relay has a rating of 5 A, 2.2 sec IDMT and a relay setting of 125% TMS = 0.6. It is connected to a supply circuit through a C.T. 400/5 ratio. The fault current is 4000 A. The operating current of the relay is

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If the fault current is 2000 A, the relay setting is 50% and CT ratio is 400:5, the plug setting multiplier will be

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An antenna located in a city is a source of radio waves. How much time does it take the wave to reach a town 12,000 km away from the city?  a. 36 s b. 20 us c. 20 ms d. 40 ms

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An alternator is connected to a bus. For a symmetrical fault at the bus, the fault level is 60 MVA. If another alternator is connected to the same bus, the new fault level will be (1) 120 MVA (2) 60 MVA (3) 30 MVA (4) 15 MVA

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A current is said to be alternating when it changes in : -  a) Magnitude only b) Direction only c) Both magnitude and direction d) None

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Draw a neat labeled diagram to show protective system for AC traction and give the function of each relay used in it.

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A system is said to be causal if (a) the system has right half poles. (b) the region of convergence include unit circle. (c) the region of convergence outside the unit circle. (d) the system has proper rational function.

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If the % reactance upto the fault point is 20%, then the short circuit current will be

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A 1000W heater is rated to operate at a direct current (DC) of 10A. If the heater is supplied alternating current (AC) for producing the same quantity of heat the value of current should be  a. Iav=10A b. Irms=10A c. Ipeak=10A

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An unsaturated dc shunt motor runs at its rated speed when rated voltage is applied to it. If the supply voltage to the motor is reduced by 25%, the speed of the motor  (a) Increases by 25% (b) Remains the same (c) Decreases by 25% (d) Decrease only slightly by an amount less than 25%

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A certain appliance uses 350 W. If it is allowed to run continuously for 24 days, how many kilowatt- hours of energy does it consume? A.20.16 kWh B.201.6 kWh C.2.01 kWh D.8.4 kWh

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If a computer on the network shares resources for others to use, it is called  (1) Server (2) Client (3) Mainframe (4) none

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A relay used for protection of motors against overload is :  (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay

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A negative sequence relay is used for protection of  (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines

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A Buchholz relay is used for:  A) Protection of a transformer against all internal faults B) Protection of a transformer against external faults C) Protection of a transformer against both internal and external faults D) Protection of instrument transformers and bus bars

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An IDMT relay of rating 5A, 2.2s and having a relay setting of 125% is connected to a supply circuit through a CT having a ratio of 400/5. The plug setting multiplier of IDMT relay in the event of fault current of 4000 A will be a. 5 b. 8 c. 10 d. 125

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For a traction transformer circuit breaker state: 1) Rated current and rupturing capacity 2) Any two tests it should be capable of withstanding 3) Overall tripping time and relay time.

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The most efficient torque — producing actuating structure for induction — type relay is:

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Reactance relay is normally preferred for protection against

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30°, 60° and 90° connections are made in a directional relay to render the relay (A) Sufficient torque under fault conditions (B) Zero torque under fault conditions (C) Current grading (D) Time grading

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To prevent mal-operation of differentially connected relay while energizing a transformer, the relay restraining coil is based with  (1) second harmonic current  (2) third harmonic current  (3) fifth harmonic current  (4) seventh harmonic current

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The zero sequence current of a generator for line to ground fault is j 2.4 p.u. The current through the neutral during the fault is (a) j 0.8 p.u (b) j 2.4 p.u. (c) j 0.24 p.u. (d) j 7.2 p.u.

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If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then  (A) zero sequence currents are present on both sides of the transformer  (B) zero sequence currents are absent on both sides of the transformer  (C) zero sequence currents are present on the secondary side but not on the primary side  (D) zero sequence currents are present on the primary side but not on the secondary side

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A radioactive isotope has a half-life of 10 days. If today there are 125 g of it left, what was its original weight 40 days earlier  (a) 600 g (b) 1000 g (c) 1250 g (d) 2000 g

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The operation of the relay which is most affected due to arc resistance is A) Mho relay B) Reactance relay C) Impedance relay D) All are equally affected

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Draw a neat sketch of earth fault protection of auxiliary circuit of electric loco. State the function of relay and isolating resistance.

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With the help of a schematic diagram explain how a overcurrent relay protects a line during short circuit fault.

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To protect the power transformer (Y-Y with neutral grounded) against fault, what type of connection do the CTs have ?

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The emf induced in a coil is 1 volt when current in it changes from 0 to 100 mA in time 10mS. Its inductance (in mH) value is  A) 10 B) 50 C) 100 D) 1000

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If the capacity of a battery is 2800 mAh, it can supply 1.4 Ampere current for

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The arc temperature in Oil Circuit Breaker may reach up to_______.  (A) 5,000° K (B) 8,000° K (C) 10,000° K (D) None of the above

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If it takes a transmitted signal 1m sec to go up to the target and come back after reflection, how far is the transmitter from the target? A) 150 Km B) 150 m C) 15 Km D) 1500 m

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To read or write a complete word from / to the memory in 8086 microprocessor and if it is located at an even address, the number of Read or Write cycles required is

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If an energy meter disc makes 10 revolutions in 100 seconds when a load of 450W is connected to it, the meter constant in revolutions per kWh is  A) 1000 B) 500 C) 1600 D) 800

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In a biased differential relay, the bias is defined as the ratio of  A) Number of turns of restraining coil and operating coil B) Operating coil current and restraining coil current C) Faulteurrent and operating coil current D) Fault current and restraining coil current