A. Less than 5 Ohms
B. Around 100 Ohms
C. Very Large
D. Around 1000 Ohms
Answer: A. Less than 5 Ohms
Explanation:
As per IE rules, the resistance between the consumer earth terminal and the earth continuity conductor must be less than 1 ohms.
Earth resistance in a typical domestic wiring must be less than 5 ohms.
The cross-sectional area of the earth wire must be less than half of the cross-sectional area of the thickest wire used in the electrical wiring installation.
Generally, the size of the copper wire used as earth continuity conductor is 3 SWG.
Earth wires smaller than 14 SWG must not be used
According to I.E. Rule 48:
The insulation resistance between the wiring of installation and earth should be of such a value that the leakage current may not exceed 1/50000 the part or 0.02 percent of the full load current.
The permissible voltage drop in a lighting circuit is 2% of the supply voltage plus one volt.
The maximum permissible voltage drop in a power industrial circuit should not be more than 5% of the declared supply voltage.
The insulation resistance of any wiring installation should not be less than 1 MΩ.
The earth resistance should not exceed the value of one Ω.