Correct Answer - Option 1 : The earth wire is much thicker in size and is made of copper.
Concept:
Distribution substation lowers down the high transmission voltage and this stepped down voltage is supplied to the domestic consumers with 1-phase, 2 wire system.
A network of wires drawn from the meter board to the various energy consuming points (fans, lamps, motors etc) through control and protective devices for efficient distribution of power is known as electrical wiring..
Explanation:
The main purpose of earth wire is to provide a low resistance path to the ground. Unwanted leakage current need to pass to the ground for safety purpose and hence earth wire fulfill this requirement.
→ This earth wire is also used to protect the device from unwanted short circuit current during faulty condition.
→ Under lightning condition it gives surge current a passage to ground.
→ An Aluminium wire of same size with copper possess high resistivity compared to copper. Hence, copper wire is a better conductor than Aluminium. Hence, copper wire is used in earth wire.
Also, we know that
\(R=\frac{\rho \cdot \ell}{A}\)
i.e. Resistance of a wire is inversely proportional to its area i.e. if area is high resistance will be less.
Therefore, in earth wire copper wire of large area is used.
→ Live wire is at a potential of 230 volts and neutral wire is at zero potential.
→ Red wire is the live or phase wire. Black wire is the neutral wire. Green wire is the earth wire.
