The transmission line distance protection relay having the property of being inherently directional is (A) impedance relay (B) MHO relay (C) OHM relay (D) reactance relay

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Answer :

The transmission line distance protection relay having the property of being inherently directional is MHO relay

Related questions

Description : A 800 kV transmission line is having per phase line inductance of 1.1 mH/km and per phase line capacitance of 11.68 nF/km. Ignoring the length of the line, its ideal power transfer capability in MW is (A) 1204 MW (B) 1504 MW (C) 2085 MW (D) 2606 MW

Last Answer : A 800 kV transmission line is having per phase line inductance of 1.1 mH/km and per phase line capacitance of 11.68 nF/km. Ignoring the length of the line, its ideal power transfer capability in MW is 2085 MW

Description : A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30%. Then, SIL of the compensated transmission line will be (A) 1835 MW (B) 2280 MW (C) 2725 MW (D) 3257 MW

Last Answer : A loss less transmission line having Surge Impedance Loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30%. Then, SIL of the compensated transmission line will be 2280 MW

Description : For a fixed value of complex power flow in a transmission line having a sending and voltage V, the real power loss will be proportional to  A) V B) v2 C) 1/V2 D)1/V

Last Answer : For a fixed value of complex power flow in a transmission line having a sending and voltage V, the real power loss will be proportional to 1/V2

Description : In order to safely carry out repairs to a generator circuit breaker, it must be isolated from the bus. This is accomplished by opening the _____________. A. reverse power relay B. bus disconnect link C. generator bus fuse connections D. power directional relay

Last Answer : Answer: B

Description : What are the features of directional relay?

Last Answer : High speed operation; high sensitivity; ability to operate at low voltages; adequate short-time thermal ratio; burden must not be excessive.

Description : Purpose of Directional inverse Over current & earth fault relay; type- CDD

Last Answer : Directional phase or earth fault protection of ring-mains, parallel transformers, transformer feeders, parallel feeders etc., employing the time graded principle.; This relay comprises an inductive ... induction disc unit. The directional unit is normally provided with voltage polarising coils. 

Description : Admittance relay is _______ relay. (a) impedance (b) directional (c) non-directional (d) none of the above

Last Answer : (b) directional

Description : Inverse definite minimum time lag relay is also called ___________ (A) pilot relay. (B) differential relay. (C) over current relay. (D) directional overcurrent relay.

Last Answer : Ans: B Inverse definite minimum time lag relay characteristic is inverse but minimum time is fixed. The operating time is inversely proportional to the magnitude of actuating quantity.

Description : Explain construction and operation of induction type directional over current relay.

Last Answer : Directional overcurrent relay: Construction: It consists of two units: i) Non-directional Over-current unit ii) Directional power unit The directional unit consists of upper electromagnet ... closes the trip circuit. This operates circuit breaker which isolates the faulty section. 

Description : 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

Last Answer : 30°, 60° and 90° connections are made in a directional relay to render the relay Sufficient torque under fault conditions

Description : In the induction type directional over current relay, when a short-circuit occurs in the circuit (A) power flows in reverse direction (B) power flows in normal direction (C) directional power element does not operate (D) over current element is not energized

Last Answer : In the induction type directional over current relay, when a short-circuit occurs in the circuit power flows in reverse direction

Description : In induction type directional over current relay the driving torque is due to interaction of magnetic fields derived from (A) current in the potential coil (B) both voltage and current in the ... (C) directional element and non-directional element (D) non-directional element and the trip circuit

Last Answer : In induction type directional over current relay the driving torque is due to interaction of magnetic fields derived from directional element and non-directional element

Description : If the phase -angle of the voltage coil of a directional relay is 50°, the maximum torque angle of the relay is: (A) 130° (B) 100° (C) 50° (D) 25°

Last Answer : If the phase -angle of the voltage coil of a directional relay is 50°, the maximum torque angle of the relay is: 50°

Description : It is useful to refer to an isotropic radiator. A. when comparing the gains of directional antennas B. when testing a transmission line for standing wave ratio C. when (in the northern hemisphere) directing the transmission D. when using a dummy load to tune a transmitter

Last Answer : A. when comparing the gains of directional antennas

Description : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator

Last Answer : C. Directional coupler

Description : When is it useful to refer to an isotropic radiator? A. When comparing the gains of directional antennas B. When testing a transmission line for standing wave ratio C. When (in the northern ... ) directing the transmission in a southerly direction D. When using a dummy load to tune a transmitter

Last Answer : A. When comparing the gains of directional antennas

Description : Best choice of transmission line component to couple a coaxial line to a parallel-wire line A. Shorting B. Balun C. Slotted line D. Directional coupler

Last Answer : B. Balun

Description : A transmission line is protected by (a) inrush protection (b) distance protection (c) time graded and current graded over current protection (d) both (b) and (c) (e) none of the above

Last Answer : (d) both (b) and (c)

Description : Which of the following is the demerit of a 'constant voltage transmission system' ? (a) Increase of short-circuit current of the system (b) Availability of steady voltage at all loads at ... of carrying increased power for a given conductor size in case of long-distance heavy power transmission

Last Answer : (a) Increase of short-circuit current of the system

Description : Which of the following is the demerit of a 'constant voltage transmission system' ? (a) Increase of short-circuit current of the system (b) Availability of steady voltage at all loads at ... of carrying increased power for a given conductor size in case of long-distance heavy power transmission

Last Answer : (a) Increase of short-circuit current of the system

Description : Explain distance protection of transmission line with neat sketch diagram.

Last Answer : Distance protection of Transmission line: Distance protection scheme uses impedance relay. The relay operation is based on the impedance (or distance) between the relay and point of fault. Figure shows ... than ZL and impedance relay operates which operates the CB and line is protected.

Description : A negative sequence relay is commonly used to protect  (A) an alternator (B) an transformer (C) a transmission line (D) a bus bar

Last Answer : A negative sequence relay is commonly used to protect  an alternator

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

Last Answer : If the fault current is 2000 A, the relay setting is 50% and CT ratio is 400:5, the plug setting multiplier will be 10 A

Description : A reactance relay is (A) Voltage restrained directional relay (B) Directional restrained over-current relay (C) Voltage restrained over current relay (D) Directional restrained over voltage relay

Last Answer : A reactance relay is Directional restrained over-current relay

Description : What is the time of operation of a relay of rating 5 amp 2.2 sec, IDMT and having a relay of setting of 125% Tms = 0.6 It is connected to a supply circuit through a CT, 400 ratio. The fault current is 400 amp.

Last Answer : 1.92 sec is the time of operation of a relay of rating 5 amp 2.2 sec, IDMT and having a relay of setting of 125% Tms = 0.6 It is connected to a supply circuit through a CT, 400 ratio. The fault current is 400 amp.

Description : A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, j0.1 and j0.04 respectively. The neutral of ... the fault is  (A) 513.8 V (B) 889.9 V (C) 1112.0 V (D) 642.2 V

Last Answer : A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, ... line. The voltage of the alternator neutral with respect to ground during the fault is 642.2 V

Description : Choose two appropriate auxiliary components of a HVDC transmission system from the following P. D.C line inductor Q. A.C line inductor R. Reactive power sources S. Distance relays on D.C line T. Series capacitance on A.C. line  (A) P and Q (B) P and R (C) Q and S (D) S and T

Last Answer : Choose two appropriate auxiliary components of a HVDC transmission system from the following P. D.C line inductor Q. A.C line inductor R. Reactive power sources S. Distance relays on D.C line T. Series capacitance on A.C. line  (A) P and Q (B) P and R (C) Q and S (D) S and T

Description : An 800 kV transmission line has a maximum power transfer capacity of P. If it is operated at 400 kV with the series reactance unchanged, the new maximum power transfer capacity is approximately (A) P (B) 2P (C) P / 2 (D) P / 4

Last Answer : An 800 kV transmission line has a maximum power transfer capacity of P. If it is operated at 400 kV with the series reactance unchanged, the new maximum power transfer capacity is approximately P / 4

Description : A generator is connected through a 20 MVA, 13.8/138 kV step down transformer, to a transmission line. At the receiving end of the line a load is supplied through a step down transformer of 10 MVA, 138/69 kV rating. A 0.72 ... load (in per unit) in generator will be (A) 36 (B) 1.44 (C) 0.72 (D) 0.18

Last Answer : A generator is connected through a 20 MVA, 13.8/138 kV step down transformer, to a transmission line. At the receiving end of the line a load is supplied through a step down transformer of 10 MVA, 138/ ... MVA and 69 kV in load circuit, the value of the load (in per unit) in generator will be 36 

Description : An HVDC link consist of rectifier, inverter transmission line and other equipments. Which one of the following is true for this link ?  (A) The transmission line produces/ supplies ... ) Both the converters (rectifier and inverter) consume reactive power from the respective connected AC systems

Last Answer : An HVDC link consist of rectifier, inverter transmission line and other equipments. Which one of the following is true for this link ?  (A) The transmission line produces/ supplies ... ) Both the converters (rectifier and inverter) consume reactive power from the respective connected AC systems

Description : For enhancing the power transmission in along EHV transmission line, the most preferred method is to connect a  (A) Series inductive compensator in the line (B) Shunt inductive compensator at the ... (C) Series capacitive compensator in the line (D) Shunt capacitive compensator at the sending end

Last Answer : For enhancing the power transmission in along EHV transmission line, the most preferred method is to connect a Series capacitive compensator in the line

Description : Which of the two generalized constants of a transmission line are equal?  (a) B & C (B) A & B (c) A & D (D) B & D

Last Answer : Which of the two generalized constants of a transmission line are equal?  (a) B & C (B) A & B (c) A & D (D) B & D

Description : Series capacitive compensation in EHV transmission line is used to

Last Answer : To maintain voltage stability 

Description : 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

Description : The transmission line feeding power on either side of the main transmission line is called?

Last Answer : The transmission line feeding power on either side of the main transmission line is called Secondary transmission.

Description : For a transmission line with negligible losses, the lagging reactive power (VAR) delivered at The receiving end, for a given receiving end voltage, is directly proportional to the?

Last Answer : For a transmission line with negligible losses, the lagging reactive power (VAR) delivered at The receiving end, for a given receiving end voltage, is directly proportional to the line voltage drop.

Description : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will?

Last Answer : A long overhead transmission line is terminated by its characteristic impedance. Under this operating condition, the ratio of the voltage to the current at different points along the line will progressively increase from the receiving end to the sending end.

Description : The time taken for a surge to travel a 600 km long overhead transmission line is?

Last Answer : The time taken for a surge to travel a 600 km long overhead transmission line is 0.002s.

Description : A lossless radial transmission line with surge impedance loading?

Last Answer : A lossless radial transmission line with surge impedance loading takes negative VAr at sending end and zero VAr at receiving end.

Description : The line conductor of a transmission line has an overall diameter of 19.53 mm, weight 0.844 kg/m and an ultimate breaking strength of 7950 kg. If the factor of safety is to be 2, when conductor ... .5 kg/m. What is the vertical sag, corresponding to this loading for a 300 m span level supports?

Last Answer : The line conductor of a transmission line has an overall diameter of 19.53 mm, weight 0.844 kg/m and an ultimate breaking strength of 7950 kg. If the factor of safety is to be 2, when conductor ... 5 kg/m. 5.22 m is the vertical sag, corresponding to this loading for a 300 m span level supports.

Description : An overhead transmission line has a span of 240m between level supports. What is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

Last Answer : An overhead transmission line has a span of 240m between level supports. 1.52 m is the maximum sag if the conductor weight 727 kg/km and has a breaking strength of 6880 kg? Allow the factor of safety of 2. Neglecting wind and ice loading.

Description : A transmission line conductor at a river crossing is supported from two towers at height. of 30 m and 90m, above water level. The horizontal distance between the towers is 270m, if the tension in ... . What is the clearance between the conductor and the water at a point midway between the towers?

Last Answer : A transmission line conductor at a river crossing is supported from two towers at height. of 30 m and 90m, above water level. The horizontal distance between the towers is 270m, if the tension ...  54.94 m is the clearance between the conductor and the water at a point midway between the towers.

Description : If in a short transmission line, resistance and inductance are found to be equal and regulation appear. to be zero, then the load will?

Last Answer : If in a short transmission line, resistance and inductance are found to be equal and regulation appear. to be zero, then the load will be 0.707 lagging.

Description : A three phase overhead transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. if now the conductors of the line are rearranged to form and the equilateral triangle of sides equal to 'd' then?

Last Answer : A three-phase overhead transmission line has its conductors horizontally spaced with spacing between adjacent conductors equal to 'd'. if now the conductors of the line are rearranged to form and an equilateral triangle of sides equal to 'd' then average capacitance and inductance will increase.

Description : For an existing ac transmission line, the string efficiency is 80%, if dc voltage is supplied for the same setup, the string efficiency will be?

Last Answer : 100%

Description :  A single-phase transmission line of impedance j 0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is?

Last Answer :  A single-phase transmission line of impedance j 0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is 0.6 lagging.

Description : A 100 km long transmission line is loaded at 110 kV.if the loss of line is 5 MW and the load is 150 MVA, the resistance of the line is?

Last Answer : P = I^2  *  R 5*10^6  = [(150*10^6) / (110*10^3)  *  R R = 2.7 ohm/phase

Description : A 100 km transmission line is designed for a nominal voltage of 132 kV and consists of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in MW, would be   (a) 240 (b) 132 (c) 416 (d) 720

Last Answer : A 100 km transmission line is designed for a nominal voltage of 132 kV and consists of one conductor per phase. The line reactance is 0.726 ohm/km. The static transmission capacity of the line, in MW, would be 240 

Description : In a DC transmission line?

Last Answer : In a DC transmission line there are no effects due to inductive and capacitive reactances.

Description : The Hawthorne studies: (a) Found that to increase worker efficiency, management must analyze and minimize the motions required to complete a task. (b) Found that when workers know they are ... that workers accept a managerial directive only if it is acceptable in terms of their personal interests.

Last Answer : (b) Found that when workers know they are being watched, their productivity increases.