1. When a high voltage overhead line passes over or adjacent to any building
the vertical clearance between the highest part of the building immediately
under such liner, recommended in IE rules is of not less than
a) 1.2m
b) 2.8m
c) 6m
d) 3.7m
Ans: d
2. What is the minimum clearance of HV lines from the ground across streets?
a) 3.1m
b) 8.1m
c) 6.1m
d) 5.1m
Ans: c
3. According to the IS code, the color of earth wire is usually
a)Red
b)Green
c)Yellow
d)Black
Ans: b
4.For what voltage levels are the screwed conduit circuits used?
a)Less than 250V
b)Between 250-600 V
c) Above 600V
d) none
Ans: b
5.What is an electrical schedule?
i. A list or a plan of a building providing information of number of
points in each room
ii. The list of all the electrical components required for a particular
room
iii. The list all the electrical components along with their prices
a) Only i
b) Only ii
c) Both ii & iii
d)None
Ans: a
6.What is the factor of safety used for current ratings in a power
installation?
a)1
b)1.5
c)1.75
d)2
Ans: d
7.What is the dimension of the copper strips used for the strip
earthing?
a) 25mm x 4mm
b) 25mm x 3mm
c)30mm x 4mm
d)30mm x 3mm
Ans: a
8.The effect of electric shock on human body depends on:
i. Current
ii. Voltage
iii.Duration of contact
a)Only I
b)Only ii
c)Only iii
d)All I, ii, iii
Ans: d
9.The purpose of earthing electric appliances is:
a) To provide safety against shock
b) To ensure that the appliances work properly
c) To ensure that the appliances get full voltage
d)None of the above
Ans: a
10.The addition of ground rods in the earthing grid:
a) Has no effect on earth resistance
b)Decrease the earth resistance
c) Slightly decrease the earth resistance
d) Slightly increase the earth resistance
Ans: c
11.For reducing tower footing resistance, it is better to use
a) Chemical and ground rod only
b) Chemical and counterpoise only
c) Ground rod and counterpoise only
d)None
Ans: c
12.Earth resistance comprises of
i.Resistance of soil away from electrode
ii.Contact resistance between electrode and soil
iii.Resistance of metal electrode
a) Only I
b)i and ii only
c) i and iii only
d)i, ii, and iii together
Ans: d
13.The aluminium conductor of size _ is used for sub circuit in
domestic wiring
a)1/1.8 mm
b) 1/2.24 mm
c) 1/1.4 mm
d) 1/1.2 mm
Ans: c
14.The type of wiring that is highly suitable for a temporary shed is
a) Cleat wiring
b)Wooden capping and casing wiring
c) Lead sheathed wiring
d) Conduit wiring
Ans: a
15.The earthing electrodes should be placed within what distance in meters
from the building whose installation system is being earthed
a) 4
b) 2.5
c) 1.5
d) 0.5
Ans: c
16.What should be the minimum clearance for laying power cables near
communication lines?
a. 0.2 m horizontally and vertically
b. 0.6 m horizontally and vertically
c. 1 m horizontally and vertically
d. 1.5 m horizontally and vertically
Ans: b
17. What are the minimum cross-sections of conductors that are used for
power wiring?
a) 2.5 mm2 and 1.25 mm2 for aluminium and copper conductors respectively.
b) 1.25 mm2 and 2.5 mm2 for aluminium and copper conductors respectively.
c) 1.5 mm2 and 1.25 mm2 for aluminium and copper conductors respectively.
d) 2.5 mm2 and 2.25 mm2 for aluminium and copper conductors respectively.
Ans: a
18. Which among these tests are to be conducted on wiring installations?
a) Testing of polarity of non linked single pole switches
b) Testing of earth continuity path
c) Testing of earth resistance
d) All of these
Ans: d
19. What should be the minimum depth of trench from the ground
level for cables carrying a voltage between 3.3 kV and 11 kV?
a) 0.75 m plus radius of complete cable
b) 0.45 m plus radius of complete cable
c) 1.0 m plus radius of complete cable
d) All of these
Ans: a
20. What should be the value of earthing resistance for large power
stations?
a) 1 Ω
b) 0.5 Ω
c) 2 Ω
d) 5 Ω
Ans: b
21.Which type of earthing is also called as ‘fire earthing’?
a) Plate earthing
b) Rod earthing
c) Strip earthing
d) All of these
Ans: b
22. should be provided as the working space around the
main switchboard according to Indian Electricity Rule 51.
a) 0.914m
b) 0.523m
c) 0.638m
d) 0.814m
Ans: a
23.What is the formula to calculate the number of poles required in LT
line distribution? a) Length / Span + 1
b) Length / Span + 10
c) Span / Length + 1
d) Span / Length + 10
Ans: a
24.What is the angle between the pole and stay?
a) 30 °
b) 45 °
c) 60 °
d) 10 °
Ans: a
25.As per IE rules the permissible variation of voltage at the consumer
end is:
a) ± 6%
b) ±10%
c) ± 12%
d) ± 2%
Ans: a
25. Which statement is true with respect to the motor installation?
a) Wood work is used for mounting switchgears
b)All equipment used in power wiring shall be of iron clad
c) Looping of conductors is usually made
d) The length of flexible conduit is more than 3m
Ans: b
26.Which type of neutral grounding method has high transient voltages
appear under fault conditions?
a) Solid grounding
b) Resistance grounding
c) Reactance grounding
d) Resistance grounding
Ans: c
27.How many earth connections are required for the motor frame as
per the IE rule 61?
a. One
b) Two separate and distinct
c) Three separate and distinct
d) All of these
e) None of these
Ans: b
28. What is the multiplication factor used for the determination of maximum
the current-carrying capacity of an 11 kV line?
a) 0.88
b) 0.95
c) 0.9
d) 0.8
Ans: c
29.The minimum permissible size of the aluminium cable for
lighting circuits is
a)1.1 sq.mm
b)1.5 sq.mm
c)2.4 sq.mm
d)3.6 sq.mm
Ans: b
30.In transmission lines the cross-arms are made of
a)Wood
b)Steel
c)RCC
d)Copper
Ans: c
31.What type of earthing is used by transmission line?
a) Plate earthing
b) Rod earthing
c) Strip earthing
d) Both plate and strip earthing
Ans: c
32. Which set of rules are to be verified on completion of wiring on any
new installation?
a)Indian Electricity rules, 1950
b)Indian Electricity rules, 1956
c)Indian Electricity rules, 1960
d)none
Ans: b
“Failure Will Never Overtake Me If My Determination To Succeed Is Strong Enough.” – O
For detail explanation of each question, you can watch this video…..