Your question says nothing.
What do you want to know by saying 100 and 200 size.
Concrete strenght depends on its grade for which it is design say m25 - it will have 25 mpa strength at 28 days
Size of block wont matter for testing strength, it only affect the capacity of testing machine and safety of person who is testing it.
Higher the size, higher load required to crush so high capacity testing machine required.
At higher load crush part may bang on person standing in front.
Compressive strenght is load / area
Area increase will result in increasing load.
Please say what you want to know