(a) On voir dire examination in a felony trial, the jurors shall be asked the following questions:

(1) "Have you, for any reason, formed and expressed any opinion in regard to the guilt or innocence of the accused?" If the juror answers in the negative, the question in paragraph (2) of this subsection shall be propounded to him;

(2) "Have you any prejudice or bias resting on your mind either for or against the accused?" If the juror answers in the negative, the question in paragraph (3) of this subsection shall be propounded to him;

(3) "Is your mind perfectly impartial between the state and the accused?" If the juror answers this question in the affirmative, he shall be adjudged and held to be a competent juror in all cases where the authorized penalty for the offense does not involve the life of the accused; but when it does involve the life of the accused, the question in paragraph (4) of this subsection shall also be put to him;

(4) "Are you conscientiously opposed to capital punishment?" If the juror answers this question in the negative, he shall be held to be a competent juror.

(b) Either the state or the defendant shall have the right to introduce evidence before the judge to show that a juror's answers, or any of them, are untrue. It shall be the duty of the judge to determine the truth of such answers as may be thus questioned before the court.

(c) If a juror answers any of the questions set out in subsection (a) of this Code section so as to render him incompetent or if he is found to be so by the judge, he shall be set aside for cause.