The public administrator shall take and subscribe an oath or affirmation in the form provided in G.S. 11-11 for administrators and in the manner provided in G.S. 28A-7-1; and the oath or affirmation so taken and subscribed shall be filed in the office of the clerk of superior court. (1868-9, c. 113, ss. 2, 5; Code, s. 1393; Rev., s. 19; C.S., s. 18; 1973, c. 1329, s. 3.)