Answer / mahesh gajera

In electrical engineering, ground or earth may be the
reference point in an electrical circuit from which other
voltages are measured, or a common return path for electric
current, or a direct physical connection to the Earth.

Neutral is a common return path for electric current, but
not directly connected to the earth.

Answer / surendhar

All electrical Circuits have ground point (the reference
point). It may be earth grounding (where reference point
connected to earth) or Chasis grounding (reference point
connected to chasis as in aircraft, car etc) or Floating
ground(where the reference point is not connected
anywhere).
Earthing, where the equipment case is connected to the
earth, to protect the equipment and the people who come in
contact with faulty conditions (Metal case of the equipment
coming in contact with the line).
If neutral is not present (floating neutral), then there
would be significant rise in the voltage at the neutral
point in the star connection (at the load end), because of
unbalancement in all three phases (practical case). This in
turn would affect the equipments connected across each
phase. So Neutral wire connects the neutral point at the
load end and the transformer end, where it would be
grounded. This causes current to flow in the neutral under
unbalanced situation, back to the transfomer, negating the
rise in voltage @ neutral point in load end.

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