5) To know about earthing
Aim :- to learn about earthing
           * There  are two types of earthing.
            1) Chemical  earthing .
            2) Normal pipe earthing .
Requirement:- GI pipe of iron , salt , coal , funnel , iron  cover , erthing wire
Procedure :-  first by measurements given we digged a hole in ground .at the end  we placed
a earthing plate. around the plate we put salt , coal mixture then placed a layer  of bricks
upon  it place a pipe between it and connected to earthing plate . then removed the other  end from the hole are connected to the chamber and other to the connection. then added
water to the chamber and tested the earthing.as per required add salt water to the chamber.
* Different parts of earthing name :-
   Earth continuting  conductor .
   Earth lead .
   Earth  resistres.
* To check earthing :-
    To check earthing tester is used and 2 pin, 3pin are two type used.
Benefits of earthing :- by earthing it is a safety first for the humans and then to machines
due to earthing leaked current is been send directly to the ground so that is harn of get or
surving through shock . We  obsereved that we know about which earthing is ok or which
earthing is not ok.
* How should earthing should be :- it must be less the 5 ohm.
* How to calculate earthing :- green wire should be connected to the earthing electrode
   and red and yellow wire we took a little distance and  how much earthing is calculated .