Vimal asked this question.
Impulse is the effect of a force and is measured as the change in momentum produced.
The same effect, that is the same change in momentum can be produced by a large force acting for a short interval of time, a small force acting for a large interval of time or a moderate force acting for a moderate interval of time.
In all these cases the impulse will be the same as the change in momentum will be the same.
