Description : The material commonly used for sheaths of underground cables is (a) lead (b) rubber (c) copper (d) iron
Last Answer : (a) lead
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 : 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
Last Answer : (e) All of the above
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 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
Last Answer : (d) 66 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 : 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 : 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 : 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
Last Answer : (d) All of the above
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 : Rubber is most commonly used insulation in cables. (a) Yes (b) No
Last Answer : (a) Yes
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 : 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 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 : Which of the following insulation is used in cables? (a) Varnished cambric (b) Rubber (c) Paper (d) Any of the above
Last Answer : (d) Any of the above
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 : In transmission lines the crossarms are made of (a) copper (b) wood (c) R.C.C. (d) steel
Last Answer : (d) steel
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 : 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 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
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 : 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 : Which of the following are the constants of the transmission lines ? (a) Resistance (b) Inductance (c) Capacitance (d) All of the above
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 : 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 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 : 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 : The underground system cannot be operated above (a) 440 V (b) 11 kV (c) 33 kV (d) 66 kV
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 : 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 : Which of the following statements best describes the material known as varnished cambric? A. Felted asbestos sealed with varnish. B. Cotton cloth coated with insulating varnish. C. Rubber ... Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.
Last Answer : Answer: B
Description : What Is Meant By Insulation Voltage In Cables? Explain It?
Last Answer : It is the property of a cable by virtue of it can withstand the applied voltage without rupturing it is known as insulation level of the cable.
Description : The thickness of the layer of insulation on the conductor, in cables, depends upon (a) Reactive power (b) Power factor (c) Voltage (d) Current carrying capacity
Last Answer : (c) Voltage
Description : The size of a conductor used in power cables depends on the (A) operating voltage. (B) power factor. (C) current to be carried. (D) type of insulation used.
Last Answer : (C) current to be carried.
Description : Cables for 220 kV lines are invariably (a) mica insulated (b) paper insulated (c) compressed oil or compressed gas insulated (d) rubber insulated (e) none of the above
Last Answer : (c) compressed oil or compressed gas insulated
Description : Solid type cables are considered unreliable beyond 66 kV because (a) insulation may melt due to higher temperature (b) skin effect dominates on the conductor (c) of corona loss between conductor and sheath material (d) there is a danger of breakdown of insulation due to the presence of voids
Last Answer : (d) there is a danger of breakdown of insulation due to the presence of voids
Description : Is a cable is to be designed for use on 1000 kV, which insulation would you prefer ? (a) Polyvinyle chloride (b) Vulcanised rubber (c) Impregnated paper (d) Compressed SFe gas (e) none of the above
Last Answer : (d) Compressed SFe gas
Description : Line losses in a distribution circuit are kept to a minimum by __________. A. adding rubber insulation conductors to the circuit B. using higher current and lower voltage C. increasing the number of thermal relays in the circuit D. using higher voltage and lower current
Last Answer : Answer: D
Description : Which of the following statements concerning electrical cables is correct? A. Where they pass through watertight bulkheads, they should be fitted with watertight stuffing boxes. B. Electric cable coverings should ... , or glued in place where nonmetallic insulation is used. D. All of the above.
Last Answer : Answer: A
Description : The intersheaths in the cables are used to (a) minimize the stress (b) avoid the requirement of good insulation (c) provide proper stress distribution (d) none of the above
Last Answer : (c) provide proper stress distribution
Description : In the cables, sheaths are used to (a) prevent the moisture from entering the cable (b) provide enough strength (e) provide proper insulation (d) none of the above
Last Answer : (a) prevent the moisture from entering the cable