The oath which the assessor shall administer to persons examined under section 54:4-16 of this title, shall be of the following or like tenor:
"I, , do swear (or affirm) that I will truly answer all questions put to me regarding my taxable property and I will speak the truth, the whole truth and nothing but the truth."
The powers conferred by this section and said section 54:4-16 upon assessors are also hereby vested in the county boards of taxation and the state board of tax appeals, or other reviewing authority, in the exercise of their duties.