WorksheetsElectrician 4th Sem Module 6 Transmission and Distribution
Total questions: 26
Worksheet time: 13mins
Name
Class
Date
1.
Which electric lines connect the substation to distributors in distribution system?
a)
Feeders
b)
Distributors
c)
Service lines
d)
Service mains
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
3.
What is diversity factor (D.F)?
a)
DF=Installed loadminimum actual load
b)
DF=minimum actual loadInstalled load
c)
DF= actual loadminimum Installed load
d)
DF= minimum Installed load actual load
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
5.
What is the name of the insulator used in O.H lines?
a)
Pin insulator
b)
Post insulator
c)
Strain insulator
d)
Shackle insulator
6.
What is the name of line insulator?
a)
Pin type insulator
b)
Disc type insulator
c)
Shackle type insulator
d)
Suspension type insulator
7.
Which is the permissble load for lighting sub circuit in domestic wiring as per IE rules?
a)
800 W
b)
1200 W
c)
2400 W
d)
3000 W
8.
What is the name of the insulator?
a)
Stay insulator
b)
Shackle insulator
c)
Suspension insulator
d)
Single shed pin insulator
9.
What is the reason for the conductor cross- sectional area can fully utilised on transmission of DC as compared to AC?
a)
No heat loss
b)
No skin effect
c)
No power loss
d)
No corona loss
10.
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 season
11.
What is the type of over head line joint?
a)
Twisted joint
b)
Straight sleeve joint
c)
Compression joint for ACSR
d)
Straight joint through connectors
12.
Why steel is reinforced in ACSR conductors used for over head 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
13.
Which type of A.C transmission is universallly adopted?
a)
Two phase four wire
b)
Two phase three wire
c)
Single phase two wire
d)
Three phase three wire
14.
Which type of line insulator is used for terminating on corner post?
a)
Pin insulator
b)
Strain insulator
c)
Shackle insulator
d)
Suspension insulator
15.
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
16.
What is the name of conductor used on overhead lines?
a)
ACSR
b)
Aluminium
c)
Galvanised iron
d)
Hard drawn copper
17.
What is the main purpose of crossarm used in electric poles?
a)
Supporting the line conductors
b)
Holding the insulators on overhead line
c)
Avoids short circuit between conductors
d)
Reduces conductor sag between supports
18.
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
19.
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
20.
What is ACSR stands for?
a)
All Conductors Steel Reinforced
b)
Aluminium Core Steel Reinforced
c)
Aluminium Covered Steel Reinforced
d)
Aluminium Conductor Steel Reinforced
21.
What is the purpose of cross-arm in O.H 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
22.
What is the advantage of over head 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 lightning discharges
23.
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
24.
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
25.
How the sparking on the aluminium cored conductors binding joints can be prevented?
a)
Keeping binding turns very close
b)
Making binding turns very tight
c)
Providing guard wires below the conductors
d)
Providing more than one binding
26.
What will happen to the skin effect on the O.H conductors, if the conductor diameter is small (<1cm)?
a)
Becomes negligible
b)
Increases to maximum
c)
No effect, remain same
d)
Decreases half of the value
100 %
