A 90-m tall office building is protected by a metal lightning conductor that runs from a pointed rod on the roof to a thick copper strip buried deep in moist soil.
Answer the following with reference to this arrangement:
(a) Name the fundamental property of electric charge that is chiefly responsible for the protective action of the lightning conductor.
(b) Explain, with qualitative reasoning, how the pointed rod and the earth connection together prevent damage to the building during a thunderstorm.
(c) Why must the top of the conductor be sharply pointed rather than flat? Answer in terms of charge distribution and its consequences.
(d) Predict what would happen during a storm if the earth connection of the conductor were accidentally broken. Give reasons for your answer.