Q.1
What is the size of copper earth plate?
  • 60cm x 60cm x 3.18mm
  • 50cm x 50cm x 3.18mm
  • 40cm x 60cm x 3.18mm
  • 65cm x 65cm x 3.18mm
Q.2
What is the minimum length pipe earthing electrode?
  • 2.75 M
  • 1.5 M
  • 2.00 M
  • 1.00 M
Q.3
What is the color of earth wire?
  • Green
  • Blue
  • Yellow
  • Red
Q.4
What is the color of earth wire?
  • Green
  • Blue
  • Yellow
  • Red
Q.5
What is the diameter of pipe earthing electrode?
  • 40mm
  • 30mm
  • 25mm
  • 60mm
Q.6
What is the minimum distance of two earth electrode?
  • 3M
  • 2M
  • 5M
  • 1M
Q.7
Charcoal and salt layer reduce.....................................
  • Earth resistance
  • Current
  • Voltage
  • None of the above
Q.8
Three pin sockets thicker pin should be connect to...........................
  • Earth continuity conductor
  • Phase
  • Neutral
  • None of the above
Q.9
Which one of the following supply systems would have three live conductors and a neutral?
  • 4 phase
  • 3 phase
  • 2 phase
  • Single phase
Q.10
What should be the value of earthing resistance for large power stations?
  • 1 Ω
  • 0.5 Ω
  • 2 Ω
  • 5 Ω
Q.11
Specific resistance of soil is _______
  • changes from soil to soil
  • is constant
  • depends on the circuit connected to it
  • depends on the supply voltage
Q.12
Earth electrode provides ___________
  • high resistance
  • medium resistance
  • low resistance
  • very high resistance
Q.13
After earthing, the different parts of an electrical machinery are at ________
  • infinite potential
  • intermediate potential
  • zero potential
  • undefined potential
Q.14
In a three phase system, the neutral is _________
  • earthed
  • connected to low voltage
  • connected to high voltage
  • not connected
Q.15
How is the condition of an earth electrode measured?
  • by measuring the voltage
  • by measuring the current
  • by measuring the power
  • by measuring resistance
Q.16
Minimum distance of underground cable form the foundation of a building should be
  • 10cm
  • 100 cm
  • 50cm
  • 5cm
Q.17
Moisture content in soil ______ the earth soil resistance
  • increases
  • decreases
  • does not affect
  • none of the above
Q.18
Which of the following are the Type of Earth Electrodes :-
  • Treated Earth pit
  • Directly driven earth electrode
  • Deep bore earth electrode
  • All of the above
Q.19
Which of the following are the ADVANTAGES OF EARTHED SYSTEM :-
  • The system earthing (solidly or through a resistance or impedance) is done to provide a return path of earth fault current, which in turn helps
  • To reduce the insulation requirement of phase elements of equipment connected in that voltage level & cost of the equipment/s in turn. VIZ: Earthed grade cables are less costly than unearthed grade cables.
  • To isolate the faulty part of the system due to earth fault by sensing earth fault current
  • All of the above
Q.20
Which of the following is the purpose of System Earthing ?
  • Controls Voltage to ground to specified limits.
  • Limits voltage stress on Insulation of conductors
  • Provides path for flow of currents during Fault
  • All of the above
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