How do we detect the smell of an agarbatti (incense stick)

Q. No. 4: How do we detect the smell of an agarbatti (incense stick)?

Ans: when the smell of the incense stick reaches to our nose then the olfactory receptors present in our nose detects it send this information in fore brain in the form of electrical signals. Fore brain interprets this information as the smell of incense stick where it is already stored.