(a) The following oath shall be administered to the foreman of the jury by the coroner:

"You, as foreman of the inquest, shall diligently inquire and true presentment make, on behalf of the State of Georgia, how and in what manner ________ (or a person deceased, unknown, as the case may be) came to his death and of such other matters relating to the same as shall be lawfully required of you, according to evidence, so help you God."

(b) The remainder of the jury shall be sworn by the coroner as follows:

"The same oath which the foreman of this inquest has taken on his part each of you shall observe and keep upon your part, so help you God."