Boiling corn on the cob takes about 10 minutes to fully cook corn on the cob.
Fill a pot about 3/4 full of water and bring the water to a boil then if you want you can add some Lemon Juice and Sugar and let it dissolve in the boiling water.
Then gently place the corn on the cob into the boiling water and let it boil for around 10 minutes and check it for tenderness.
If the corn on the cob isn't tender enough for you then you can boil it a little bit longer.
I use tongs when placing corn on the cob in the boiling water since it makes it easier and prevents me from burning my hand.