In general, questions in written English are used more in informal rather than formal language. I’d therefore advise candidates not to use them in Part 1.
However, in Part 2, if the register required is informal, you can certainly use questions to good effect.
For example, if you have to write a letter or email to a friend, a few questions in the introduction – How are you? How was your holiday? Have you finished your exams? etc. – make your style friendly and chatty.
If you choose to write an article, questions in the introduction are a great way to attract your reader’s attention. For instance, imagine you have to answer a question like this:
What’s your favourite city to visit as a tourist and why?
If you include a couple of questions in your opening paragraph – Have you ever been to Paris? Do you know that it’s one of the most beautiful cities in the world? – then you make your reader think. Specifically, your reader wants to know why Paris is, in your opinion, so beautiful. The rest of the article can then answer this question.
A few well-chosen questions can improve the style of your email / letter / article, and style is part of Communicative Achievement.