In any school district in this State whose limits are coextensive with the limits of any city of five thousand inhabitants or more the school board, when authorized to do so by the majority vote of the electors of any such school district voting on the proposition, may establish, maintain or discontinue a junior college to consist of not more than two years of college work beyond a four-year high school course and may charge such tuition fees for instruction in such junior college as shall be fixed by any such school board.