A. 12 Ω
B. 0.5 Ω
C. 2 Ω
D. 50 Ω
Answer: B. 0.5 Ω
Explanation:
Value of Earth Resistance for Different Equipment
Equipment to be earthed VS Maximum Value of Resistance Under Worst Conditions
Large power stations-----0.5 Ω
Major substations------1.0 Ω
Small substations-------2.0 Ω
Factories substations------1.0 Ω
Lattice steel towers --------3.0 Ω
Industrial machines and equipment----------0.5 Ω
According to Indian Electricity Rules, the value of earthing resistance for large power stations should be 0.5 Ω