Final answer:
Grounding a lightning rod helps in preventing lightning damage by safely directing the electrical discharge into the Earth, while attaching a rod without grounding only provides a pathway for lightning, leaving the building at risk. Option a is the correct answer.
Step-by-step explanation:
When discussing the pros and cons of a lightning rod being grounded versus simply attached to a building, we must understand the function of a lightning rod and the effect of grounding. A lightning rod is designed to protect structures from lightning damage by providing a controlled pathway for the electrical discharge. Grounding a lightning rod means connecting it to the Earth using materials that conduct electricity well, which allows the excess electrical charge to safely dissipate into the ground.
Pros of grounding a lightning rod include the critical benefit of preventing lightning damage by directing the lightning strike safely into the ground, away from the structure. This also reduces the risk of fire or electrical surges that could damage a building's electrical systems. However, one con is the misconception that grounding attracts lightning. In reality, lightning rods do not attract lightning but rather provide a safe path for it if the building happens to be struck.
On the other hand, simply attaching a lightning rod to a building without proper grounding only provides a pathway for the lightning. This could be potentially dangerous as it fails to direct the harmful electrical current away from the building's structure and inhabitants. Without grounding, the protection is incomplete, and the building is still at risk of damage.
Therefore, the correct answer is: (a) Grounding prevents lightning damage; Attachment provides a pathway for lightning.