The usual spans with R.C.C. poles are_______________?

Related Mcqs:

1. 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

2. Most of the high transmission lines in Pakistan are_______________?

   A. underground
   B. overhead
   C. either of the above
   D. none of the above

3. 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

4. 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

5. 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

6. 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

7. 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 the line terminals
   C. Possibility of better protection for the line due to possible use of higher terminal reactants
   D. Improvement of power factor at times of moderate and heavy loads
   E. Possibility of carrying increased power for a given conductor size in case of long-distance heavy power transmission

8. Multicore cables generally use________________?

   A. square conductors
   B. circular conductors
   C. rectangular conductors
   D. sector-shaped conductors
   E. none of the above

9. Transmitted power remaining the same, if supply voltage of a D.C. 2-wire feeder is increased 100 percent, saving in copper is____________________?

   A. 25 percent
   B. 50 percent
   C. 75 percent
   D. 100 percent

10. A feeder, in a transmission system, feeds power to________________?

    A. distributors
    B. generating stations
    C. service mains
    D. all of the above