Recent questions tagged transmission

Description : Good Non-Intel (G4 mac mini running 10.5.8) Torrent engine?

Last Answer : Older versions of Transmission?

Description : What are the building restrictions concerning power/transmission lines?

Last Answer : There is none in North Carolina—- They just put in a transmission line right down the road with houses at 75 foot set-back from road on both sides of the road. The towers are taller than the driveways are long!

Description : On a 4x4 if you have the FWD shifter in neutral will it hurt the vehicle?

Last Answer : It’s not gonna go anywhere if it’s in N.

Description : What seems to be the problem with my '94 Toyota Celica?

Last Answer : It’s 15 years old?

Description : Is the pilot bearing shot in my '94 Celica?

Last Answer : My suggestion? Put less of the question in the title, more in the description, then call The Car Guys. ...and welcome to Fluther.

Description : Transmission leaks?

Last Answer : Purple.

Description : Explain some of the methods to improve the strength of transmission system?

Last Answer :  Introducing or adding of new transmission lines in to the system to avoid the overloading of the existing lines  Application of devices such as series capacitors in the right location of ... system  Adoption of multi-voltage levels an multi-circuits in the existing ac transmission system

Description : What are the factors that limit the maximum power transfer capability in a transmission line?

Last Answer : Answer: Some of the factors which limits the maximum power transfer are: 1. Electrical phase shift 2. Voltage drop 3. Thermal effects in the line

Description : Why does surge impedance loading (SIL) increase with increase in voltage level?

Last Answer : Answer: SIL varies as the square of the operating voltage, so SIL increases with increase in voltage level

Description : What are the problems associated with EHV transmission?

Last Answer : Answer: The problems associated with EHV transmission are corona loss and radio interference, requirement of heavy supporting structures and insulation requirments

Description : What is the material used for overhead transmission lines?

Last Answer : Answer: ACSR conductors are employed.

Description : What for series and shunt compensation provided in EHV transmission lines?

Last Answer : Answer: Series capacitance is provided in EHV lines to artificially reduce the series reactance of the line so as to improve stability, voltage regulation and transmission efficiency Shunt compensation ... reduce the line susceptance so as to improve the voltage regulation under light load condition

Description : Series capacitors on transmission lines are of little use when the load VAR requirement is (a) large (b) small (b) fluctuating (d) any of the above

Last Answer : (b) small

Description : Electro-mechanical voltage regulators are generally used in (a) reactors (b) generators (c) transformers (d) all of the above

Last Answer : (b) generators

Description : The angular displacement between two interconnected stations is mainly due to (a) armature reactance of both alternators (b) reactance of the interconnector (c) synchronous reactance of both the alternators (d) all of the above

Last Answer : (a) armature reactance of both alternators

Description : When an alternator connected to the bus-bar is shut down the bus-bar voltage will (a) fall (b) rise (c) remain unchanged (d) none of the above

Last Answer : (c) remain unchanged

Description : The frequency of voltage generated, in case of generators, can be increased by (a) using reactors (b) increasing the load (c) adjusting the governor (d) reducing the terminal voltage (e) none of the above

Last Answer : (c) adjusting the governor

Description : When the interconnector between two stations has large reactance (a) the transfer of power will take place with voltage fluctuation and noise (b) the transfer of power will take place with least loss ... out of step be¬cause of large angular displacement between the stations (d) none of the above

Last Answer : (c) the stations will fall out of step be¬cause of large angular displacement between the stations

Description : In the analysis of which of the following lines shunt capacitance is neglected ? (a) Short transmission lines (b) Medium transmission lines (c) Long transmission lines (d) Medium as well as long transmission lines

Last Answer : (a) Short transmission lines

Description : 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

Last Answer : (a) 150 to 220 kV

Description : The effect of corona can be detected by (a) presence of ozone detected by odour (b) hissing sound (c) faint luminous glow of bluish colour (d) all of the above

Last Answer : (d) all of the above

Description : Constant voltage transmission entails the following disadvantage (a) large conductor area is required for same power transmission (b) short-circuit current of the system is increased (c) either of the above (d) none of the above

Last Answer : (b) short-circuit current of the system is increased

Description : In a tap changing transformer, the tappings are provided on (a) primary winding (b) secondary winding (c) high voltage winding (d) any of the above

Last Answer : (b) secondary winding

Description : Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical ? (a) Static condenser (b) Synchronous condenser (c) Tap changing transformer (d) Booster transformer

Last Answer : (d) Booster transformer

Description : For aluminium, as compared to copper, all the following factors have higher values except (a) specific volume (6) electrical conductivity (c) co-efficient of linear expansion (d) resistance per unit length for same cross-section

Last Answer : (6) electrical conductivity

Description : 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

Last Answer : (a) 132 kV

Description : Aluminium has a specific gravity of (a) 1.5 (b) 2.7 (c) 4.2 (d) 7.8

Last Answer : (b) 2.7

Description : Pin type insulators are generally not used for voltages beyond (a) 1 kV (b) 11 kV (c) 22 kV (d) 33 kV

Last Answer : (d) 33 kV

Description : The current drawn by the line due to corona losses is (a) non-sinusoidal (b) sinusoidal (c) triangular (d) square

Last Answer : (a) non-sinusoidal

Description : The use of strain type insulators is made where the conductors are (a) dead ended (b) at intermediate anchor towers (c) any of the above (d) none of the above

Last Answer : (c) any of the above

Description : The voltage drop, for constant voltage transmission is compensated by installing (a) inductors (b) capacitors (c) synchronous motors (d) all of above (e) none of the above

Last Answer : (c) synchronous motors

Description : In a substation the following equipment is not installed (a) exciters (b) series capacitors (c) shunt reactors (d) voltatre transformers

Last Answer : (a) exciters

Description : A circuit is disconnected by isolators when (a) line is energized (b) there is no current in the line (c) line is on full load (d) circuit breaker is not open

Last Answer : (b) there is no current in the line

Description : By which of the following a bus-bar is rated ? (a) Current only (b) Current and voltage (c) Current, voltage and frequency (d) Current, voltage, frequency and short time current

Last Answer : (d) Current, voltage, frequency and short time current

Description : In aluminium conductors, steel core is provided to (a) compensate for skin effect (b) neutralise proximity effect (c) reduce line inductance (d) increase the tensile strength

Last Answer : (d) increase the tensile strength

Description : By which of the following methods string efficiency can be improved ? (a) Using a guard ring (b) Grading the insulator (c) Using long cross arm (d) Any of the above (e) None of the above

Last Answer : (d) Any of the above

Description : Owing to skin effect (a) current flows through the half cross-section of the conductor (b) portion of the conductor near the surface carries more current and core of the conductor carries less current (c) ... core of the conductor carries more cur¬rent (d) any of the above (e) none of the above

Last Answer : (b) portion of the conductor near the surface carries more current and core of the conductor carries less current

Description : Which of the following bus-bar schemes has the lowest cost ? (a) Ring bus-bar scheme (b) Single bus-bar scheme (c) Breaker and a half scheme (d) Main and transfer scheme

Last Answer : (b) Single bus-bar scheme

Description : In AC.S.R. conductors, the insulation between aluminium and steel conductors is (a) insulin (b) bitumen (c) varnish (d) no insulation is required

Last Answer : (d) no insulation is required

Description : A conductor, due to sag between two supports, takes the form of (a) semi-circle (b) triangle (c) ellipse (d) catenary

Last Answer : (d) catenary

Description : Which of the following regulations is considered best? (a) 50% (b) 20% (c) 10% (d) 2%

Last Answer : (d) 2%

Description : Transmission voltage of ll kV is normally used for distances upto (a) 20—25 km (b) 40—50 km (c) 60—70 km (d) 80—100 km

Last Answer : (a) 20—25 km

Description : Which of the following characteristics should the line supports for transmission lines possess ? (a) Low cost (b) High mechanical strength (c) Longer life (d) All of the above

Last Answer : (d) All of the above

Description : Which of the following distribution systems is more reliable ? (a) Radial system (b) Tree system (c) Ring main system (d) All are equally reliable

Last Answer : (c) Ring main system

Description : The steel used in steel cored conductors is usually (a) alloy steel (b) stainless steel (c) mild steel (d) high speed steel (e) all of the above

Last Answer : (c) mild steel

Description : Which of the following relays is used on long transmission lines ? (a) Impedance relay (b) Mho's relay (c) Reactance relay (d) None of the above

Last Answer : (b) Mho's relay

Description : There is a greater possibility of occurence of corona during (a) dry weather (b) winter (c) summer heat (d) humid weather (e) none of the above

Last Answer : (d) humid weather

Description : Which of the following is not a constituent for making porcelain insulators ? (a) Quartz (b) Kaolin (c) Felspar (d) Silica

Last Answer : (d) Silica

Description : Which of the following materials is used for overhead transmission lines ? (a) Steel cored aluminium (b) Galvanised steel (c) Cadmium copper (d) Any of the above

Last Answer : (d) Any of the above

Description : A 3-phase 4 wire system is commonly used on (a) primary transmission (b) secondary transmission (c) primary distribution (d) secondary distribution

Last Answer : (d) secondary distribution