The resistance of the Conductor is depending upon the area
of cross section of conductor i.e(R=6L/A), so we are
connected earth wire to the big one terminal of the socket
point as well as 3 pin top. To flow the fault current
through the terminal to earth easily.
1) To withstand fault current. that is any short circuit
occur, all fault currents flow through earth.so earth
pin and plug give heavily.
2) any where should give earth first then connect power. so
earth pin give long.
1,we know if the cross section area increase resistance decreases.To decreases the resistance ,dia increased.And the length is to conduct first before power supply inserts
so when short circuit occurred the short circuit current will conduct earth point first,and flows through it because resistance is low
As we know that Resistance is directly proportional to
lenth and Inversily proportional to area of conductor .
due to more area of cross section of earth point in compare
to Phase and neutral short circuit current will flow to
direction which have low resistance i.e. to earth point.