Transmission And Distribution Of Electrical Energy Set 1 MCQs

Q1 | By which of the following systems electric power may be transmitted ?

Overhead system

Underground system

Both (a) and (b)

None of the above

Q2 | are the conductors, which connect the consumer’s terminals to the distribution

Distributors

Service mains

Feeders

None of the above

Q3 | The underground system cannot be operated above

440 V

11 kV

33 kV

66 kV

Q4 | Overhead system can be designed for operation up to

11 kV

33 kV

66 kV

400 kV

Q5 | 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 corresponding size of conductor will be most economical. This statement is known as

Kelvin’s law

Ohm’s law

Kirchhoffs law

Faraday’s law

Q6 | The wooden poles well impregnated with creosite oil or any preservative compound have life

from 2 to 5 years

10 to 15 years

25 to 30 years

60 to 70 years

Q7 | Which of the following materials is not used for transmission and distribution of electricalpower ?

Copper

Aluminium

Steel

Tungsten

Q8 | Galvanised steel wire is generally used as

stay wire

earth wire

structural components

all of the above

Q9 | The usual spans with R.C.C. poles are

40—50 meters

60—100 meters

80—100 meters

300—500 meters

Q10 | The corona is considerably affected by which of the following ?

Size of the conductor

Shape of the conductor

Surface condition of the conductor

All of the above

Q11 | Which of the following are the constants of the transmission lines ?

Resistance

Inductance

Capacitance

All of the above

Q12 | 310 km line is considered as

a long line

a medium line

a short line

any of the above

Q13 | The phenomenon qf rise in voltage at the receiving end of the open-circuited or lightly loadedline is called the

Seeback effect

Ferranti effect

Raman effect

none of the above

Q14 | The square root of the ratio of line impedance and shunt admittance is called the

surge impedance of the line

conductance of the line

regulation of the line

none of the above

Q15 | Which of the following is the demerit of a ‘constant voltage transmission system’ ?

Increase of short-circuit current of the system

Availability of steady voltage at all loads at the line terminals

Possibility of better protection for the line due to possible use of higher terminal reactants

Improvement of power factor at times of moderate and heavy loads

Q16 | The operating voltage of high voltage cables is up to

l.lkV

3.3kV

6.6kV

llkV

Q17 | The operating voltage of supertension cables is up to

3.3 kV

6.6 kV

11 kV

33 kV

Q18 | The operating voltage of extra high tension cables is upto

6.6 kV

11 kV

33 kV

66 kV

Q19 | Which of the following methods is used for laying of underground cables ?

Direct laying

Draw-in-system

Solid system

All of the above

Q20 | Which of the following is the source of heat generation in the cables ?

Dielectric losses in cable insulation

losses in the conductor

Losses in the metallic sheathings and armourings

All of the above

Q21 | Due to which of the following reasons the cables should not be operated too hot ?

The oil may loose its viscosity and it may start drawing off from higher levels

Expansion of the oil may cause the sheath to burst

Unequal expansion may create voids in the insulation which will lead to ionization

All of the above

Q22 | Which of the following D.C. distribution system is the simplest and lowest in first cost ?

Radial system

Ring system

Inter-connected system

None of the above

Q23 | A booster is a

series wound generator

shunt wound generator

synchronous generator

none of the above

Q24 | Besides a method of trial and error, which of the following methods is employed for solution of network problems in interconnected system ?

Circulating current method

Thevenin’s theorem

Superposition of currents

All of the above

Q25 | Which of the following faults is most likely to occur in cables ?

Cross or short-circuit fault

Open circuit fault

Breakdown of cable insulation

All of the above