(a) In addition to the qualifications provided for judges by Tenn. Const. art. VI, §§ 3 and 4, judges of the supreme court, court of appeals, chancery courts, circuit courts, criminal courts, and courts exercising the jurisdiction imposed in one (1) or more of the chancery courts, circuit courts or criminal courts, shall be learned in the law, which must be evidenced by the judge being authorized to practice law in the courts of this state.

(b)

(1) This section shall not apply to courts of general sessions in counties of this state having a population according to the federal census of 1960 or any subsequent federal census as follows:

(2) This section shall not apply to judges of the county courts nor to chairs of county courts in the various counties of this state except in those counties where such judges or chairs exercise general criminal jurisdiction normally exercised by the criminal and circuit courts, jurisdiction of purely civil cases in which a jury is provided for, except insanity proceedings and condemnation of land proceedings, and jurisdiction to hear and determine divorce cases.

(c)

(1) Notwithstanding any provision of subsection (b) to the contrary, this section shall apply to any county having a population of not less than two hundred eighty-seven thousand seven hundred (287,700) nor more than two hundred eighty-seven thousand eight hundred (287,800), according to the 1980 federal census or any subsequent federal census.

(2) Subdivision (c)(1) shall have no effect unless it is approved by a two-thirds (⅔) vote of the county legislative body of any county to which it may apply. Its approval or nonapproval shall be proclaimed by the presiding officer of the county legislative body and shall be certified by such officer to the secretary of state.

(d) Notwithstanding any other public or private act, law or charter provision, subsection (a) shall also apply to judges of city courts of all cities of this state having a population in excess of one hundred sixty thousand (160,000), according to the federal census of 1980 or any subsequent federal census.