Here is an example.. A student was studying about the chemical structure of atom, he read the sentence “protons reside in the nucleus of atom” he started thinking in his mind “proton have positive charge, bodies having same charge repel each other, then how protons reside in same place, why they don’t repel each other?” He made a question “How protons (having same charge) reside in one place, why they don’t repel each other? He will definitely use his brain to find its answer or ask teacher for it. By making such question you achieve perfection in your learning.