1. Any party may serve upon any adverse party written interrogatories to be answered by the party served or, if the party served is a public or private corporation or a partnership or association, by any officer, director, partner or managing agent thereof competent to testify in its behalf.
2. The interrogatories shall be answered separately and fully in writing under oath. The answers shall be signed by the person making them; and the party upon whom the interrogatories have been served shall serve a copy of the answers on the party submitting the interrogatories within fifteen days after the delivery of the interrogatories, unless the court, on motion and notice and for good cause shown, enlarges or shortens the time.
3. Objections to any interrogatories may be presented to the court within ten days after service thereof, with notice as in case of a motion; and answers shall be deferred until the objections are determined, which shall be at as early a time as is practicable.
4. No party may, without leave of court, serve more than one set of interrogatories to be answered by the same party.