Question

Lightning occurs when there is a flow of electric charge (principally electrons) between the ground and a thundercloud. The maximum rate of charge flow in a lightning bolt is about 20,000 C/s this lasts for 100 μs or less.
1.How much charge flows between the ground and the cloud in this time? (Q= ? C)
2.How many electrons flow during this time? (n_e = ? )

Answer 1

Answer:

$1.25\times 10^{19}\ electrons$

Explanation:

r = Rate of flow of charge = 20000 C/s

t = Time taken = 100 μS

Charge is given by

$Q=rt\\\Rightarrow Q=20000\times 100\times 10^{-6}\\\Rightarrow Q=2\ C$

The charge that flows between the ground and the cloud in this time is 2 C

Number of electrons is given by

$n_e=\dfrac{Q}{e}\\\Rightarrow n_e=\dfrac{2}{1.6\times 10^{-19}}\\\Rightarrow n_e=1.25\times 10^{19}\ electrons$

The number of electrons is $1.25\times 10^{19}\ electrons$