Question

why is electric current and not charge taken as thefundamental quantity in SI unit ?Why?

Answer 1

For a quantity to be fundamental we should be able to measure it directly. E.g you can measure mass and length directly, so they are fundamental. However we have no instrument to measure the magnitude of charge, we have instruments to find whether a body is positively or negatively charged or which is more charged and which ones less but we don't have any instrument to measure the magnitude. Since we can measure current directly with amemeter so it is the fundamental quantity though it comes due to flow of charge per unit time.