Rule 611 - Mode and order of interrogation and presentation(a) Control by court. - The court shall exercise reasonable control over the mode and order of interrogating witnesses and presenting evidence so as to (1) make the interrogation and presentation effective for the ascertainment of the truth, (2) avoid needless consumption of time, and (3) protect witnesses from harassment or undue embarrassment.(b) Scope of cross-examination. - A witness may be cross-examined on any matter relevant to any issue in the case, including credibility.(c) Leading questions. - Leading questions should not be used on the direct examination of a witness except as may be necessary to develop his testimony. Ordinarily leading questions should be permitted on cross-examination. When a party calls a hostile witness, an adverse party, or a witness identified with an adverse party, interrogation may be by leading questions.