As a complement to Mr. Kennedy's answer (leading question), I would point out that simply calling this a "question" might contain a second, implicit, fallacy; unless one is aware of the real reason why the question is being asked.
The usual assumption, is that one asks a question in order to acquire new information. There is a theory of information (Shannon) that takes into account the probability of each distinct answer. Here you have one answer, with a probability of 1. So as a heuristic tool, this question does not foot the bill.
Traditionally, asking a question to which one already knows the answer is called rhetorical question.
So the question about this question might be: "why are you asking me a question to which you already know the answer?".
There might be a number of reasons, all of which come under the heading of "I want you to state what I already know". Offhand, I can think of two:
The "handshake" ("are you there?"): it ensures (for telecom devices) that the other device is still reachable through the line, and in a conversation or speech, that your audience is still paying attention. So the real question, is: "Do I still have a communication?". In the extreme, whatever one asks is irrelevant; a sentence ("d'you see what I mean?"), a simple word ("yeah?") or even a question mark ("?") would suffice.
The maieutic question: the purpose of the question is to make the audience think about something (relatively obvious), so they indirectly come to a realization ("aha!").
Note that both are daily used by teachers or lecturers.
Finally, I suppose that your concern about the leading question, is that it could be used with a "pitch" (a salesman) or a "curve" (a political or court opponent), in which case the question might also be loaded! In that case, the purpose might not be to increase your knowledge, but to muddy it.
