Answer:
1 column - 3 x 10⁹ start columb
= 1 / 10 e mu
column is a bigger unit so in practice the smaller unit micro column is also used the smaller unit of charge
1 Milli column - 10-³
1 micro column 10-⁶
COLUMB LAW-
the force of attraction or illusion between the two point charge is directly proportional to the product of the magnitude and inversely proportional to the square of distance between them the direction of force along line joining the two charge
hope it's helpful