Is there a word for "pretending to ask?"

I would probably use the word "obligatory" for this purpose:

Obligatory: ...

(3) so commonplace as to be a convention, fashion, or cliché

[Merriam-Webster Dictionary]

For example, I've been working on a project recently and have a friend who is really knowledgeable on it. I'll regularly call him and ask for advice, and our conversations will start:

Me: Hey I have a quick question for you, but let me offer an obligatory "What's up?" first.

Him: Nothing, what's your question?

He and I both know I'm not really calling to talk about "What's up" in the middle of a work day, but it's a little abrupt to call someone out of the blue and begin grilling them with questions. That said, I know he usually only has a few minutes to talk during the day, so it lets him know that I'm not just trying to dawdle on the phone. Of course, it runs the risk of being considered rude based on the context it's used in, such as:

After John's brother died I sent him the obligatory bouquet of flowers.

This might be taken as a rather insensitive thing to say, as it could be interpreted as me saying that responding to the death of his brother is a mundane chore for me.

Acts like this fall under the category of politesse. Basically, the adherence to social norms and decourousness.

In a roundabout way, the question can also be said to be rhetorical. You are asking a question for which the answer is obvious or implied and you don't really expect an answer.