Question

If there are 8 divisions btween the mark 0 and 0.4 A mark of an ammeter what is the least count

Answer 1

Least count means the smallest division that you can measure using that instrument.
Given that, there are 8 divisions between the mark 0 and 0.4 A of an ammeter.
We have to calculate it's least count.
Least count = (0.4 - 0) / 8 
Least count = 0.4 / 8
Least count = 0.05 A
This is the required answer.
Hopefully it is helpful.
Thanks.