What happens to voltage in the ground as the radius increases around the crane after power line contact?

What happens to voltage in the ground as the radius increases around the crane after power line contact?

• A. It remains the same
• B. It decreases
• C. It increases
• D. It becomes unpredictable

Answer: (B)

When a crane makes contact with a live power line, the ground potential rise is strongest at the point of contact and fades as you move away. This happens because the current that enters the soil fans out in all directions through a conductive medium that isn’t a perfect conductor. Near the entry, the current density is high, creating a large voltage difference in the surrounding soil. As you go farther, the same current spreads over a larger area, the current density drops, and the voltage in the ground drops accordingly. In simple terms, the ground voltage around the contact decreases with distance, roughly because the ground behaves like a spreading current source and the potential diminishes as you move outward.

When a crane makes contact with a live power line, the ground potential rise is strongest at the point of contact and fades as you move away. This happens because the current that enters the soil fans out in all directions through a conductive medium that isn’t a perfect conductor. Near the entry, the current density is high, creating a large voltage difference in the surrounding soil. As you go farther, the same current spreads over a larger area, the current density drops, and the voltage in the ground drops accordingly. In simple terms, the ground voltage around the contact decreases with distance, roughly because the ground behaves like a spreading current source and the potential diminishes as you move outward.