Utah Code § 78B-5-103: Court to decide questions of law.

All questions of law, including the admissibility of evidence, the facts preliminary to admission, the construction of statutes and other writings, the application of the rules of evidence, and all discussions of law are to be addressed to and decided by the court. Whenever the knowledge of the court is by law made evidence of a fact, the court shall explain the knowledge to the jury, who are to accept it.