Hypophora is the question similar to question tag:
I want to shift the discipline from physics to biology. Why? Because, ...
Should I ask this kind of question in my SOP?
The major purpose of using hypophora is to create curiosity among the readers, while a well-timed silence produces heightened effects and creates interest. It helps to capture the attention of the audience. However, hypophora can also be employed to introduce new discussions or topics of importance about which the readers might not have information. Also, it can be used as a directional device to change the topic. It can raise that type of questions which readers might already have on their minds and would like to get answers to. In addition, it is frequently used in political speeches as well as literary works.
I don't think it will make any harm, but I'm not sure. Why? Because this comment makes me have to rethink of any, erm, nonstandard things.