Is lightning AC or DC?

The simple answer is that, overall, it’s mostly DC. However, it also has large transient current pulses before and during the main stroke.
Lightning is a capacitive discharge. You can think of the cloud and the ground as two plates of a capacitor charged to a very high voltage. When the insulation of the air breaks down it ionizes, and a very large DC current flows from one plate to the other down the ionized path.

You can also Read :
Interview Questions
MCQ or objective