A 3-phase 4 wire system is commonly used on__________?
There is a greater possibility of occurence of corona during__________?
Which of the following is not a constituent for making porcelain insulators ?
Which of the following materials is used for overhead transmission lines ?
The power transmitted will be maximum when__________?
A feeder, in a transmission system, feeds power to__________?
The presence of ozone due to corona is harmful because it__________?
For an overhead line, the surge impedance is taken as__________?
Which of the following is usually not the generating voltage ?
As compared to a 2-wire D.C. distributor, a 3-wire distributor with same maximum voltage to earth uses only__________?
A uniformly-loaded D.C. distributor is fed at both ends with equal voltages. As compared to a similar distributor fed at one end only, the drop at the middle point is__________?
Transmitted power remaining the same, if supply voltage of a D.C. 2-wire feeder is increased 100 percent, saving in copper is__________?
Large industrial consumers are supplied electrical energy at__________?
The spacing between phase conductors of a 220 kV line is approximately equal to__________?
The minimum clearance between the ground and a 220 kV line is about__________?
The material commonly used for sheaths of underground cables is__________?
The material generally used for armour of high voltage cables is__________?
In transmission lines the cross-arms are made of__________?
Overhead lines generally use__________?
The power factor of industrial loads is generally__________?
The loads on distributors systems are generally__________?
The material commonly used for insulation in high voltage cables is__________?
Multicore cables generally use__________?
High voltage transmission lines use__________?
The distributors for residential areas are__________?
Most of the high transmission lines in Pakistan are__________?
The voltage of the single phase supply to residential consumers is__________?
Besides a method of trial and error, which of the following methods is employed for solution of network problems in interconnected system ?
A booster is a__________?
Which of the following D.C. distribution system is the simplest and lowest in first cost ?
Which of the following methods is used for laying of underground cables ?
The operating voltage of extra high tension cables is upto__________?
The operating voltage of supertension cables is up to__________?
The operating voltage of high voltage cables is up to__________?
Which of the following is the demerit of a ‘constant voltage transmission system’ ?
The square root of the ratio of line impedance and shunt admittance is called the__________?
The phenomenon qf rise in voltage at the receiving end of the open-circuited or lightly loaded line is called the__________?
310 km line is considered as__________?
Which of the following are the constants of the transmission lines ?
The corona is considerably affected by which of the following __________?
The usual spans with R.C.C. poles are__________?
Galvanised steel wire is generally used as__________?
Which of the following materials is not used for transmission and distribution of electrical power__________?
The wooden poles well impregnated with creosite oil or any preservative compound have life__________?
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__________?
Overhead system can be designed for operation up to__________?
The underground system cannot be operated above__________?
__________are the conductors, which connect the consumer’s terminals to the distribution?
By which of the following systems electric power may be transmitted ?
When a live conductor of public electric supply breaks down and touches the earth which of the following will happen?
The skin effect of a conductor will reduce as the__________?

Owing to skin effect:

A. current flows through the half cross-section of the conductor
B. portion of the conductor near the surface carries more current and core of the conductor carries less current
C. portion of the conductor near the surface carries less current and core of the conductor carries more cur¬rent
D. any of the above
E. none of the above

Correct Answer: portion of the conductor near the surface carries more current and core of the conductor carries less current ✔

Last Updated: September 29, 2021