Question

What is lightning? Explain the phenomenon.

Answer 1

Step 1: Lightning introduction:

Lightning is the visible discharge of electricity that occurs when a region of a cloud acquires an excess electrical charge either positive or negative, that is sufficient to break down the resistance of air

Step 2: Brief discussion about lightning:

1. Lightning is usually associated with cumulonimbus clouds (thunderclouds), but it also occurs in stratiform clouds (layered clouds with a large horizontal extent), in snowstorms and dust storms, and sometimes in the dust and gases emitted by erupting volcanoes.
2. During a thunderstorm, lightning can occur within the cloud, between clouds, between the cloud and the air, or between the cloud and the ground
3. Lightning occurs when regions of excess positive and negative charge develop within the cloud.
4. Typically, there is a large volume of positive charge in the upper regions of the cloud, a large negative charge in the center, and a small positive charge in the lower regions. These charges reside on water drops, ice particles, or both

Step 3: Lightning phenomena

1. At the earthling point, a heavy impulse current reaching the order of tens of kilo amperes occurs, which is responsible for the known damage of lightning.
2. The velocity of progression of the return stroke is very high and may reach half the speed of light.
3. The corresponding current heats its path to temperatures up to 20,000°C, causing the explosive air expansion that is heard as thunder.
4. The current pulse rises to its crest in a few microseconds and decays over a period of tens or hundreds of microseconds.