According to the internet, a lightning strike contains about 5 billion joules or 5 GJ. How was this calculated?
Another thing: Once the lightning strike a metal grounded rod, a current will flow. What type of that current and how much current? I think it will be a 325 MV current which is the voltage of the lightning. Is that correct?
Edit: after i read a little bit about lightning , i found it was such a big scale , so how about a small electrostatic charge , say from a 1 MV van de graaff generator, i have a spark source ( my CRT TV :D ) and i will buy a multimeter and conduct some experiments , but i need to know what to expect
The energy in a static discharge is 1/2 * voltage * charge. For a 1MV VDG with a 1 meter sphere that's approximately 1/2 * 55µC * 1MV = 27.5J However that's too much to do experiments safely. You should stay far below 1J. Also mutimeters don't like sparks or high voltages of several kV.