(a) Before testifying, every witness shall be required to declare that he or she will testify truthfully by oath or affirmation administered in a form calculated to awaken the witness's conscience and impress the witness's mind with the duty to do so.
(b) Notwithstanding the provisions of subsection (a) of this Code section, in all proceedings involving dependency as defined by Code Section 15-11-2 and in all criminal proceedings in which a child was a victim of or witness to any crime, the child shall be competent to testify, and the child's credibility shall be determined as provided in this chapter.