What are different strengths of Ritalin?

The effect of Ritalin depends on how much and how you take it, if you take Ritalin in the way it is supposed to be taken then you will be able to concentrate more and be less distracted, however if abused Ritalin becomes more like speed and the user becomes happier and the work/task he/she has to do becomes more exciting and they become more motivated to do it.