What is the minimum requirement for an Ipad 2 plug?, What is the minimum requirement for an Ipad 2 plug?

My Ipad is not charging and I am thinking I might need a new plug, but before I do I want to check the plugs I have around the house. I know that I cannot use an Ipod plug, because it isnt strong enough. I have a generic one I picked up but want to check it against my requirement. Can anyone help me? It's an easy answer if you know where to look, but Idon't. Thanks!