Objective Questions on Transmission & Distribution for Electrician Trade
| Sr. No. | Questions with options |
| 1 | Which electric lines connect the substation to distributors in distribution system?
(a) Feeders (b) Distributors (c) Service lines (d) Service mains Ans –(a) |
| 2 | What is the insulation resistance between any two conductors in a medium voltage domestic installation as per IE rules?
(a) Infinity (b) More than one Mega ohm (c) More than two Mega ohms (d) More than three Mega ohms Ans – (b) |
| 3 | What is diversity factor (D.F)?
(a) DF= minimum actual load/ installed load (b) DF= installed load/ minimum actual load (c) DF= minimum installed load/ actual load (d) DF= actual load/ minimum installed laod Ans – (a) |
| 4 | What is the voltage ratio in A.C distribution line adopted for domestic consumers?
(a) 415 V/ 240 V (b) 240 V/ 110 V (c) 415 V/ 110 V (d) 11 KV/ 415 V Ans – (a) |
| 5 | Which is the permissible load for lighting sub circuit in domestic wiring as per IE rules?
(a) 800 W (b) 1200 W (c) 2400 W (d) 3000 W Ans – (a) |
| 6 | What is the reason for the conductor cross-sectional area can fully utilized on transmission of DC as compared to AC?
(a) No heat loss (b) No skin effect (c) No power loss (d) No corona loss Ans – (b) |
| 7 | Why the disc pin insulators outer surface is made by glazing and bent the sides inward?
(a) To withstand high voltage (b) Not to attract birds to sit on it (c) To offer high mechanical strength (d) Disables continuous water flow in rainy Ans – (d) |
| 8 | Why steel is reinforced in ACSR conductors used for overhead lines?
(a) To minimize the line sag (b) To reduce the line voltage drop (c) To increase the tensile strength (d) To increase the current carrying capacity Ans – (c) |
| 9 | Which type of A.C transmission is universally adopted?
(a) Two phase four wire (b) Two phase three wire (c) Single phase two wire (d) Three phase three wire Ans – (c) |
| 10 | Which type of line insulator is used for terminating on corner post?
(a) Pin insulator (b) Strain insulator (c) Shackle insulator (d) Suspension insulator Ans – (c) |
| 11 | What is the reason of keeping binding wire gap too close and very tight in pin insulator?
(a) Avoid sparking (b) Avoid corrosion (c) Avoid oxide formation (d) Avoid atmospheric pressure Ans – (a) |
| 12 | What is the name of conductor used on overhead lines?
(a) ASCR (b) Aluminum (c) Galvanized iron (d) Hard drawn copper Ans – (a) |
| 13 | What is the main purpose of cross arm used in electric poles?
(a) Supporting the line conductors (b) Holding the insulators on overhead line (c) Avoid short circuit between conductors (d) Reduce conductor sag between supports Ans –(b) |
| 14 | Which type of line insulator is used at the dead ends of the H.T overhead lines?
(a) Pin insulator (b) Disc insulator (c) Stay insulator (d) Post insulator Ans – (b) |
| 15 | What is the advantage of AC power transmission?
(a) Corona loss negligible (b) Stress on transmission lines is minimum (c) Low voltage drop in transmission lines (d) Voltages can be stepped up and stepped down easily Ans – (d) |
| 16 | What is ACSR stands for?
(a) All conductors steel reinforced (b) Aluminium core reinforced (c) Aluminum covered steel reinforced (d) Aluminium conductor steel reinforced Ans – (d) |
| 17 | What is the purpose of cross arm in OH lines?
(a) Provide more support to the O.H pole (b) Protect from short between conductors (c) Reduce the sag of the lines between poles (d) Holding the insulators where the conductors are fastened Ans – (d) |
| 18 | What is the advantage of overhead lines compared to underground cable?
(a) Public safety is more (b) Faults can be located easily (c) No interference with the communication lines (d) Not liable to the hazards from lighting discharges Ans – (b) |
| 19 | Which substation the transmission line voltage is stepped down to consumer supply voltage?
(a) Mobile substation (b) Mining substation (c) Secondary substation (d) Distribution substation Ans – (d) |
| 20 | What will happen to the string arrangement of disc insulators, if one of the disc insulator gets damaged?
(a) Whole string become useless (b) No effect operates normally (c) Only the damaged disc will not function (d) Damaged insulator and the adjacent insulator will not function Ans –(c) |
| Published On – 14th June 2022 | |
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