A. Provide path for leakage current
B. Provide electric shock safety
C. Provide constant line voltage
D. All of the above
Answer: D. All of the above
Explanation:
Earthing means setting up an electrical bond between a given point in a network, installation, or machine and an earth electrode.
This earth electrode is a conductive part that may be inserted in the ground or in a conductive medium, in electrical contact with the Earth.
Purposes of Earthing
It provides a surface around and under a sub-station, which would be at a uniform potential and as near to zero or absolute earth potential as possible.
Ensure people in the surrounding area are not exposed to electric shock.
Better performance of the electrical system.
To protect the human being from disability or death from shock in case the human body comes into the contact with the frame of any electrical machinery, appliance, or component, which is electrically charged due to leakage current or fault.
To maintain the line voltage constant. To serve as the return conductor for telephone and fraction work.
Earthing enables leakage currents to flow away safely and, if it is linked to an automatic cut-off device, can ensure that the power supply to the electrical installation is switched off.