Question 1

Grounding transformer is used where neutral .........available

Accepted Answer

A)  is
B)  is not
C)  either a or b
D)  . none of the above B

Question 2

Which of the following decreases within turn decreases the charging rate?

Accepted Answer

A)  temperature
B)  pressure
C)  enthalpy
D)  entropy A

Question 3

In case of earth fault, the underground neutral system----------------lead to arcing ground

Accepted Answer

A)  does
B)  does not
C)  any of above
D)  none of above A

Question 4

Which of the following causes the corrosion of terminals and clamps?

Accepted Answer

A)  spilled electrolyte
B)  increase in temperature
C)  decrease in pressure
D)  due to high current

Question 5

The advantage of neutral earthing

Accepted Answer

A)  safety of personnel
B)  reduction of earth fault current
C)  elimination of arcing ground
D)  none of the above

Question 6

In a substation the equipment used to limit short circuit current level is

Accepted Answer

A)  series reactor
B)  coupling capacitor
C)  lightening switch
D)  isolator.

Question 7

Ground resistance value for sensitive installations is

Accepted Answer

A)  less than 5 ?
B)  more than 5 ?
C)  equal to 50 ?
D)  any of above

Question 8

Grounding transformer is used where neutral                  available

Accepted Answer

A)  is
B)  is not
C)  any of above
D)  none of above

Question 9

Earthing is necessary to give protection against

Accepted Answer

A)  danger of electric shock
B)  voltage fluctuation
C)  overloading
D)  high temperature of the conductors

Question 10

In equipment grounding, the enclosure is connected to ...........wire

Accepted Answer

A)  ground
B)  neutral
C)  phase
D)  either a or b

Question 11

In a star connected system without neutral grounding, zero sequence currents are

Accepted Answer

A)  zero
B)  phaser sum of phase currents
C)  same as rms value of phase currents
D)  same as peak value of phase currents

Exam 4: Understanding Grounding and Earthing in Electrical Systems

Grounding transformer is used where neutral .........available