400 Important Transmission and Distribution MCQ Question and Answer | PDF Free Download
1.For high-voltage transmission lines, conductors are suspended from towers to
- AIncrease clearance from ground
- BReduce clearance from ground
- CTake care of increase in length
- DReduce wind and snow effects
2.The supports used for transmission lines should have the characteristics of
- AHigh mechanical strength and longer life.
- BGood looking, light in weight and easily accessible for painting and erection of line conductors.
- CCheap in initial as well in maintenance cost.
- DAll of the above
3.The wooden poles well impregnated with creosote oil or any preservative compound have life of
- A25 ? 30 years
- B20 ? 25 years
- C10 ? 15 years
- D5 ? 10 years
4.Steel poles for transmission lines need protection against
- ABorer
- BTermites
- CCorrosion
- DAll of these
5.RCC poles usually have the spans of
- A250 ? 400 meter
- B80 ? 150 meter
- C50 ? 80 meter
- D25 ? 50 meter
6.In India for distribution of electric power we usually use
- AWooden poles
- BSteel poles
- CRCC poles
- DBoth (b) and (c)
7.Conductors used in high tension transmission lines are stranded because of
- AIncreased tensile strength
- BEase in handling
- CCheaper in cost
- DReduced resistivity
8.Which of the following properties has got higher value for aluminium in comparison to that of copper?
- AElectrical resistivity
- BMelting point
- CThermal conductivity
- DSpecific gravity
9.Grease is added between steel and aluminium conductors in a ACSR Conductors to
- AReduce corrosion by electrolytic action between zinc (galvanising agent on steel) and aluminium.
- BReduce friction between the strands.
- CReduce leakage of current from aluminium strands to steel strands.
- DEliminate air pockets.
10.ACSR is used in place of copper in overhead lines because of
- AHigher current carrying capacity
- BBeing lighter in weight
- CEconomy
- DHigher tensile strength
11.ACSR conductors have
- AAll conductors made of aluminium.
- BOuter conductors made of aluminium.
- CInner conductors made of aluminium.
- DNo conductors made of aluminium.
12.The function of steel wire in an ACSR conductor is to
- ACompensate for skin effect.
- BTake care of surges.
- CProvide additional mechanical strength.
- DReduce inductance.
13.The material used for the manufacture of ground wire is
- AAluminium
- BGalvanised steel
- CCast iron
- DStainless steel
14.Guy wire is employed for
- AProviding protection against surges
- BProviding emergency earth route
- CSupporting the pole
- DAll of the above
15.The sag of a transmission line is least affected owing to
- AWeight of the conductor
- BCurrent through the conductor
- CAtmospheric temperature
- DIce deposition on the conductor
16.Effect of temperature rise in overhead lines is to
- AIncrease the sag and decrease the tension
- BDecrease the sag and increase the tension
- CIncrease both
- DDecrease both
17.In a transmission line, sag depends upon
- ASpan length
- BTension in conductors
- CWeight of the conductor per unit length
- DAll of the above
18.Which of the following statements is correct?
- AIce on conductors increases skin effect.
- BWind pressure reduces corona effect.
- CWind pressure is taken to act at perpendicular to that for ice.
- DIce on conductors reduces sag.
19.The maximum tension in a section of overhead line conductor between two supports of unequal height occurs at
- AThe higher support
- BThe lower point
- CThe midpoint of the conductor
- DNone of the above
20.Stringing chart is useful
- AFor finding the sag in the conductor
- BIn the design of tower
- CIn the design of insulator string
- DFinding the distance between towers