Answer:

Explanation:
r = Rate of flow of charge = 20000 C/s
t = Time taken = 100 μS
Charge is given by

The charge that flows between the ground and the cloud in this time is 2 C
Number of electrons is given by

The number of electrons is 
Wow ! This question reads like it might have come from one of
Faraday or Maxwell's original laboratory notebooks.
Choice-A is the correct one, when you consider what "conductance"
means. Conductance is just 1/resistance .
So when you see
"A) Current is proportionate to the conductance of the circuit and
precisely proportional to the voltage applied across the circuit."
what it's saying is
"Current is inversely proportional to the resistance of the circuit, and
directly proportional to the voltage applied across the circuit."
If you write the equation for all those words, it looks like
I = V / R
and that's correct.
Answer:
Given speed of light in diamond =1.24*10m/s
speed of light (c) =3*10^8m/s
refractive index of diamond =3*10^8/1.24*10=2.41*10^7m/s
It is a solid substance that has a conductivity between that of an insulator and that of most metals, either due to the addition of an impurity or because of temperature effects