Low cost
High mechanical strength
Longer life
All of the above
Answer is Right!
Answer is Wrong!
Transmission and distribution
12. Which of the following relays is used on long transmission lines?
Impedance relay
Mho's relay
Reactance relay
None of the above
Answer is Right!
Answer is Wrong!
Detailed SolutionWhich of the following relays is used on long transmission lines?
13. In transmission lines the cross-arms are made of
Copper
Wood
R.C.C.
Steel
Answer is Right!
Answer is Wrong!
Detailed SolutionIn transmission lines the cross-arms are made of
14. 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
Answer is Right!
Answer is Wrong!
Detailed SolutionDue to which of the following reasons the cables should not be operated too hot?
15. The loads on distributors systems are generally
Balanced
Unbalanced
Either of the above
None of the above
Answer is Right!
Answer is Wrong!
Detailed SolutionThe loads on distributors systems are generally
16. 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
Kirchhoff's law
Faraday's law
Answer is Right!
Answer is Wrong!
17. The distributors for residential areas are
Single phase
Three-phase three wire
Three-phase four wire
None of the above
Answer is Right!
Answer is Wrong!
18. In a substation the following equipment is not installed
Exciters
Series capacitors
Shunt reactors
Voltaire transformers
Answer is Right!
Answer is Wrong!
Detailed SolutionIn a substation the following equipment is not installed
19. Overhead lines generally use
Copper conductors
All aluminium conductors
A.C.S.R. conductors
None of these
Answer is Right!
Answer is Wrong!
20. Aluminium has a specific gravity of
1.5
2.7
4.2
7.8
Answer is Right!
Answer is Wrong!