(1) An oath or affirmation in the prescribed manner shall be administered to every member of every court- martial and to the judge advocate before the commencement of the trial.

(2) Every person giving evidence before a court- martial shall be examined after being duly sworn or affirmed in the prescribed form.

(3) The provisions of sub- section (2) shall not apply where the witness is a child under twelve years of age and the court- martial is of opinion that though the witness understands the duty of speaking the truth, he does not understand the nature of an oath or affirmation.