Description : By which of the following systems electric power may be transmitted ? (a) Overhead system (b) Underground system (c) Both (a) and (b) (d) None of the above
Last Answer : (c) Both (a) and (b)
Description : High voltage transmission lines use (a) suspension insulators (b) pin insulators (c) both (a) and (b) (d) none of the above
Last Answer : (a) suspension insulators
Description : Most of the high voltage transmission lines in India are (a) underground (b) overhead (c) either of the above (d) none of the above
Last Answer : (b) overhead
Description : Overhead lines generally use (a) copper conductors (b) all aluminium conductors (c) A.C.S.R. conductors (d) none of these
Last Answer : (c) A.C.S.R. conductors
Description : In transmission lines the crossarms are made of (a) copper (b) wood (c) R.C.C. (d) steel
Last Answer : (d) steel
Description : Which of the following are the constants of the transmission lines ? (a) Resistance (b) Inductance (c) Capacitance (d) All of the above
Last Answer : (d) All of the above
Description : Overhead system can be designed for operation up to (a) 11 kV (b) 33 kV (c) 66 kV (d) 400 kV
Last Answer : (c) 66 kV
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 : The material commonly used for sheaths of underground cables is (a) lead (b) rubber (c) copper (d) iron
Last Answer : (a) lead
Description : Which of the following methods is used for laying of underground cables ? (a) Direct laying (b) Draw-in-system (c) Solid system (d) All of the above
Description : The underground system cannot be operated above (a) 440 V (b) 11 kV (c) 33 kV (d) 66 kV
Last Answer : (d) 66 kV
Description : Distribution lines in India generally use (a) wooden poles (b) R.C.C. poles (c) steel towers (d) none of the above
Last Answer : (b) R.C.C. poles
Description : The material generally used for armour of high voltage cables is (a) aluminium (b) steel (c) brass (d) copper
Last Answer : (b) steel
Description : The material commonly used for insulation in high voltage cables is (a) lead (b) paper (c) rubber (d) none of the above
Last Answer : (b) paper
Description : 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
Description : The operating voltage of high voltage cables is up to (a)l.lkV (b)3.3kV (c)6.6kV (d)llkV
Last Answer : (d)llkV
Description : Which of the following materials is not used for transmission and distribution of electrical power ? (a) Copper (b) Aluminium (c) Steel (d) Tungsten
Last Answer : (d) Tungsten
Description : The voltage of the single phase supply to residential consumers is (a) 110 V (b) 210 V (c) 230 V (d) 400 V
Last Answer : (c) 230 V
Description : The operating voltage of supertension cables is up to (a) 3.3 kV (b) 6.6 kV (c) 11 kV (d) 33 kV
Last Answer : (d) 33 kV
Description : The phenomenon qf rise in voltage at the receiving end of the open-circuited or lightly loaded line is called the (a) Seeback effect (b) Ferranti effect (c) Raman effect (d) none of the above
Last Answer : (b) Ferranti effect
Description : The advantage of cables over overhead transmission lines is (a) easy maintenance (b) low cost (c) can be used in congested areas (d) can be used in high voltage circuits
Last Answer : (c) can be used in congested areas
Description : Bundled conductors are mainly used in high voltage overhead transmission lines to (a) Reduce line loss (c) Reduce corona (b) Reduce harmonics (d) Increase strength
Last Answer : Bundled conductors are mainly used in high voltage overhead transmission lines to Reduce corona
Description : The minimum clearance between the ground and a 220 kV line is about (a) 4.3 m (b) 5.5 m (c) 7.0 m (d) 10.5 m
Last Answer : (c) 7.0 m
Description : Multicore cables generally use (a) square conductors (b) circular conductors (c) rectangular conductors (d) sector-shaped conductors (e) none of the above
Last Answer : (d) sector-shaped conductors
Description : The distributors for residential areas are (a) single phase (b) three-phase three wire (c) three-phase four wire (d) none of the above
Last Answer : (c) three-phase four wire
Description : Besides a method of trial and error, which of the following methods is employed for solution of network problems in interconnected system ? (a) Circulating current method (b) Thevenin's theorem (c) Superposition of currents (d) Direct application of Kirehhoffs laws (e) All of the above
Last Answer : (e) All of the above
Description : A booster is a (a) series wound generator (b) shunt wound generator (c) synchronous generator (d) none of the above
Last Answer : (a) series wound generator
Description : Which of the following D.C. distribution system is the simplest and lowest in first cost ? (a) Radial system (b) Ring system (c) Inter-connected system (d) None of the above
Last Answer : (a) Radial system
Description : Due to which of the following reasons the cables should not be operated too hot ? (a) The oil may loose its viscosity and it may start drawing off from higher levels (b) Expansion of the ... instability may rise due to the rapid increase of dielectric losses with temperature (e) All of the above
Description : The square root of the ratio of line impedance and shunt admittance is called the (a) surge impedance of the line (b) conductance of the line (c) regulation of the line (d) none of the above
Last Answer : (a) surge impedance of the line
Description : 310 km line is considered as (a) a long line (b) a medium line (c) a short line (d) any of the above
Last Answer : (a) a long line
Description : The corona is considerably affected by which of the following ? (a) Size of the conductor (b) Shape of the conductor (c) Surface condition of the conductor (d) All of the above
Description : The usual spans with R.C.C. poles are (a) 40—50 meters (b) 60—100 meters (c) 80—100 meters (d) 300—500 meters
Last Answer : (c) 80—100 meters
Description : Galvanised steel wire is generally used as (a) stay wire (b) earth wire (c) structural components (d) all of the above
Last Answer : (d) all of the above
Description : The wooden poles well impregnated with creosite oil or any preservative compound have life (a) from 2 to 5 years (b) 10 to 15 years (c) 25 to 30 years (d) 60 to 70 years
Last Answer : (c) 25 to 30 years
Description : If variable part of annual cost on account of interest and depreciation on the capital outlay is equal to the annual cost of electrical energy wasted in the conductors, the total annual cost will be minimum and the ... (b) Ohm's law (c) Kirchhoffs law (d) Faraday's law (e) none of the above
Last Answer : (a) Kelvin's law
Description : are the conductors, which connect the consumer's terminals to the distribution (a) Distributors (b) Service mains (c) Feeders (d) None of the above
Last Answer : (b) Service mains
Description : Differentiate between overhead transmission and underground transmission.
Last Answer : Points Overhead line Underground cable Capital cost Less More Erecting cost Less More Time require for completion of work Less More Flexibility More ... Space consumed Space consumed No space consumed Appearance Not good Very good
Description : Why Earth Wire is provided in the overhead transmission lines?
Last Answer : Earth wire is provided above the overhead transmission lines for protection against lightning strokes. The ground wire or earth wire protects the phase conductors or line conductors by attracting itself the ... traveling waves set in the lines by acting a short circuit secondary of the line current
Description : What is the material used for overhead transmission lines?
Last Answer : Answer: ACSR conductors are employed.
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 : Why are overhead transmission lines not insulated?
Last Answer : Insulators are useful to help separate electrical conductors when they come into physical contact. Overhead Transmission Lines Are Not Insulated: The overhead transmission line is carrying extreme high voltage and ... a whole lot of thick insulation to absorb the heat produced by such high voltage.
Description : ACSR (Aluminium Conductor Steel Reinforced) are used as (A) over head transmission lines. (B) super conductors. (C) fuse (D) underground cables.
Last Answer : (A) over head transmission lines.
Description : Why underground service connections are service connections are costly than overhead service connection
Last Answer : Reason: Underground service connection is given by underground cable. This cable is costly than bare conductor. Sometimes cable trench is required for cable laying, which requires additional cost. So underground service connections are costly than overhead service connection.
Description : What happens insulators when high voltage passes through transmission lines whether it breaks or lose it's insulating property?
Last Answer : I think it will breaks when it crosses breakdown voltage .
Last Answer : Transmission lines use high voltage to reduce the amount of power loss over long distance. This power loss can come from large current running through the cable due to the resistance of the cable conductor. Stepping up the voltage reduces the amount of current through transmission lines.
Description : Transmission lines are either balanced or unbalanced with respect to _________. A. negative terminal B. input C. ground D. positive terminal
Last Answer : C. ground
Description : A single-line-to-ground fault on a overhead transmission line creates (A) voltage sag (B) voltage swell (C) over voltage (D) voltage flicker
Last Answer : Creates overvoltage.