"Unmarked" wh- questions tend to end in a falling pitch

Wh- question sentences—those are the questions that begin with the words ‘who, what, where, when, why’ and ‘how’—typically end in a falling pitch. This is opposite of the pattern for yes/no questions, whose pitch boundaries normally rise. 

Just as in all sentences, the content words—those are the nouns, main verbs, adjectives, and adverbs—are more likely to be stressed than function words. The final content word of the sentence usually gets more emphasis than any other word of the sentence. The pitch is likely to change on that word, then fall at the end of the wh- question sentence.

Purpose of a rising pitch in wh- questions

While wh- questions typically end in a falling pitch, there are reasons a rising pitch can be used. Ending a wh- question with a rising pitch could be asking for repetition or clarification of previously known information.

Ending "Where should we go for dinner?" in a rising pitch may signal that the topic was already discussed. Perhaps the answer was forgotten or even never decided, so the speaker is asking for confirmation.

Similarly asking, "What time's the meeting?" with a falling pitch is requesting basic information. Using a rising pitch, however, could indicate that the speaker wants to verify the schedule. 

Purpose of high-rising pitch in wh- questions

Speaker who want to show surprise, shock, disbelief, etc., can use a high-rising pitch on a wh- question.

Asking "What time's the meeting?" with a high-rising pitch is showing surprise. Perhaps the meeting is being held very early, or very late, or at a time that conflicts with another event. The listener will know, based on pitch, that the speaker is not purely asking to know when the meeting is scheduled, but is also adding clues about their own perspective of the subject.

Notice that the question word itself was stressed more in the questions that are showing surprise, shock, and disbelief.