For low voltage applications (below 1 kV),_______cables are used.

For low voltage applications (below 1 kV),_______cables are used.

(A) paper insulated (B) plastic (C) single core (D) oil filled
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1 Answer

Answer :

For low voltage applications (below 1 kV), single core cables are used.

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Related questions

If voltage at the two ends of a transmission line is 132 kV and its reactance is 40 Ohms, the capacity of the...

Description : If voltage at the two ends of a transmission line is 132 kV and its reactance is 40 Ohms, the capacity of the line will be: (A) 435.6 MW (B) 217.8 MW(C) 251.5 MW (D) 500 MW

Last Answer : If voltage at the two ends of a transmission line is 132 kV and its reactance is 40 Ohms, the capacity of the line will be: 435.6 MW

For LV applications (below 1 kV), ______________ cables are used. (A) Paper insulated. (B) Plastic. (C) Single core cables. (D) Oil filled.

Description : For LV applications (below 1 kV), ______________ cables are used. (A) Paper insulated. (B) Plastic. (C) Single core cables. (D) Oil filled.

Last Answer : Ans: C For low voltage applications single core cables are suitable.

A practical formula for determining the thickness of insulation between low voltage and high voltage windings is (a) 1 + 0.2 kVmm (6) 2 + 0.5 kVmm (c) 4 + 0.7 kV mm (d) 5 + 0.9 kV mm

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The magnetizing reactance of a 4 kV/ 400 V, 50 Hz single-phase transformer on low voltage side is 35 Ω.

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If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer : A. As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

Why the earthing transformer primary voltage is 16.5 kV rated in main generator even though actual voltage during the E/F is root 3 times less?

Description : Why the earthing transformer primary voltage is 16.5 kV rated in main generator even though actual voltage during the E/F is root 3 times less?

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If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer :  As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

The operating voltage of extra high tension cables is upto (a) 6.6 kV (b) 11 kV (c) 33 kV (d) 66 kV (e) 132 kV

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cables are used for 132 kV lines. (a) High tension (b) Super tension (c) Extra high tension (d) Extra super voltage

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For transmission of power over a distance of 500 km, the transmission voltage should be in the range (a) 150 to 220 kV (b) 100 to 120 kV (c) 60 to 100 kV (d) 20 to 50 kV

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For transmission of power over a distance of 200 km, the transmission voltage should be (a) 132 kV (b) 66 kV (c) 33 kV (d) 11 kV

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Last Answer : (a) 132 kV

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Which of the following is usually not the generating voltage ? (a) 6.6 kV (b) 8.8 kV (c) 11 kV (d) 13.2 kV

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The voltage at the two ends of a transmission line are 132 KV and its reactance is 40 ohm. The Capacity of the line is (A) 435.6 MW (B) 217.8 MW (C) 251.5 MW (D) 500 MW

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The generation voltage is usually (A) between 11 KV and 33 KV. (B) between 132 KV and 400 KV. (C) between 400 KV and 700 KV. (D) None of the above.

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A 100 km transmission line is designed for a nominal voltage of 132 kV and consists of one

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Description : How many volts is 13.8 kV?

Last Answer : 13,800 volts1 kv = 1 kilovolt = 1000 volts

How many volts is 13.8 kV?

Description : How many volts is 13.8 kV?

Last Answer : 13,800 volts1 kv = 1 kilovolt = 1000 volts

The dielectric strength of a vacuum or dry air is approximately ________________. A. 450 volts/inch B. 1000 volts/inch C. 20-kv/inch D. 50-kv/inch

Description : The dielectric strength of a vacuum or dry air is approximately ________________. A. 450 volts/inch B. 1000 volts/inch C. 20-kv/inch D. 50-kv/inch

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Why 1.1 kV grade cables used for 415V?

Description : Why 1.1 kV grade cables used for 415V?

Last Answer : To take care of the both earthed / unearthed systems.  

What are the types of cables used in 6.6 kV and 415 V system voltages?

Description : What are the types of cables used in 6.6 kV and 415 V system voltages? 

Last Answer : In 6.6 kV system AC (unearthed) grade having stranded aluminium conductors cables are used. Their insulation's are as follows. 1. XLPE - Crossed linked polyethylene insulation. 2. FRLS PVC - Fire ... V grade copper or aluminium stranded cables are used. Their insulations are HR PVC and FS type. 

What are the interlocks between 415 V and 6.6 kV switch gear?

Description : What are the interlocks between 415 V and 6.6 kV switch gear? 

Last Answer : 6.6 kV Breaker closed cannot rack in or out. Service lever cannot move while breaker closed. Breaker cannot be closed in in-between position. 415 V Breaker door cannot be opened when breaker is ... . Breaker cannot be closed in in-between position. Breaker closed cannot be rack in or out. 

What is the difference between lockout of 6.6 kV and 415 V CB’s?

Description : What is the difference between lockout of 6.6 kV and 415 V CB’s?

Last Answer : Voltage levels. Manual / auto reset. Lockout relays of 415 V breakers are all Electro-magnetic type. There is no mechanical latch. But in 6.6 kV it is of mechanical latch type relays.

What is the distribution of DC control supply in CL IV, III, II- 415V and 6.6 kV?

Description : What is the distribution of DC control supply in CL IV, III, II- 415V and 6.6 kV?

Last Answer : Closing coil and Trip coil 2 supply from one source. Trip coil 1 supply from one source. Protections supply from one source. 

What are the levels of SF6 gas in 220 kV breaker and their significance?

Description : What are the levels of SF6 gas in 220 kV breaker and their significance?

Last Answer : 7 kg/cm2 - normal pressure 5.2 bar - alarm 5.0 bar - closing/tripping operation blocked. 

What is the type of 220 kV circuit breaker?

Description : What is the type of 220 kV circuit breaker? 

Last Answer : 220 kV, SF6 breaker, single pole, puffer type. 

What are the main parts of 220 kV Circuit Breaker?

Description : What are the main parts of 220 kV Circuit Breaker? 

Last Answer : Pole column filled with SF6 Pneumatic drive system with compressed air circuit Control cubicle unit 

Give the details of switchyard 220 kV CB, Isolator, CT, CVT and lightning arrestor.

Description : Give the details of switchyard 220 kV CB, Isolator, CT, CVT and lightning arrestor.  

Last Answer : 220 kV SF6 Circuit Breaker 1. Make - ABB 2. Air pressure blocking a. Close Block - 17.3 bar. b. Open block - 16.7 bar. c. Auto reclose block - 19 bar. 3. SF6 pressure block a. Alarm - 5. ... , storage and erection. Rated voltage : 216 kV rms. Operating voltage : 184 kV rms. 

How 6.6 kV-bus supply was chosen?

Description : How 6.6 kV-bus supply was chosen?

Last Answer : 11 kV was rejected in view of the high insulation cost with 11 kV motors. 3.3 kV was rejected, since max motor size with 3.3 kV bus is limited to 2 MW. But we are having the motors having rating more than 2 MW, which cannot suit to 3.3 kV bus. 6.6 kV bus we can start upto 5 mw size motor. 

Why resistance grounding preferred for less than 33 kV and more than 415 V?

Description : Why resistance grounding preferred for less than 33 kV and more than 415 V?

Last Answer : a) To limit the earth fault current for equipment safety else, high short ckt forces dislocate in windings/bus bars etc, b) Over voltage due to arcing ground reduced c) Permits earth fault protection (not possible in ungrounded system)

Why neutrals are solid grounded above 33 kV?

Description : Why neutrals are solid grounded above 33 kV? 

Last Answer : a) Less transient over voltage due to arcing grounds. b) Voltage of phases are limited to phase to ground voltage. (No neutral shifting) c) Allows graded insulation of transformer (low cost) d) Fast E/F protection. 

Why core balance CT is preferred over residual connected CT’s to sense earth fault in 6.6 kV feeders?

Description : Why core balance CT is preferred over residual connected CT’s to sense earth fault in 6.6 kV feeders?

Last Answer : a) To avoid relay mal-operation due to CT saturation b) Better sensitivity is got. c) High pickup and TMS avoided in IDMT earth fault relay. 

Why 2 types of earth fault relays in 6.6 kV side of transformers?

Description : Why 2 types of earth fault relays in 6.6 kV side of transformers?

Last Answer : I – Trips 6.6 kV breakers only. It gives primary protection for 6.6 kV bus bars. I1 – Trips the both HT and LT breakers. It acts as a backup to ref and also acts as backup to bus bar earthfault relay. 

What is the design basis of 6.6 kV aluminium bus bars?

Description : What is the design basis of 6.6 kV aluminium bus bars?  

Last Answer : a) Temperature rises not exceed 90 ºC. b) Withstand short ckt stresses. c) Take care of thermal expansion. 

During unit operation can we have one UT feeding both unit 6.6 kV loads?

Description : During unit operation can we have one UT feeding both unit 6.6 kV loads? 

Last Answer : No, logically prevented.  

Why 6.6 kV transformer is resistance grounded by 10 ohms and current limited to 400 A?

Description : Why 6.6 kV transformer is resistance grounded by 10 ohms and current limited to 400 A?

Last Answer : a) To reduce burning and melting in faulted switchgear or machine. b) To reduce mechanical stresses in equipment. c) To reduce the electrical hazards by stray ground fault currents in the ground ... screen in 6.6 kV XLPE (cross-linked polyethylene). Therefore the cost of the cable decreases.