Question

Describe the condition in the atmosphere due to a lightning strike and state the electrical property that makes it dangerous to natural and man-made structures.

Answer 1

Lightning strikes earth due to the large potential difference (upto an order of 100 Million Volts) between the earth and the clouds, due to which ionization of air takes place at high temperatures (30,000 kelvin)

The electrical breakdown of air (ionization) normally take 3,000,000 volts per meter, however with the impurities in the air, ionization normally takes place at much lower voltages during a storm. When the lightning comes near the surface of earth, it loses much of its energy, but still has enough to destroy tall tress and small houses.The maximum power generated in lightning is upto 10^12 Watts.

Lightning strikes the metals first, because its easy to transmit power through the metals, that's why tall buildings have, proper earthing for lightning strikes.

You can model it by creating high voltages using a transformer, and show that, how electric sparks propagates through air.