(1) Whoever, except in the cases provided for by sub- section (2), commits rape shall be punished with imprisonment of either description for a term which shall not be less than seven years but which may be for life or for a term which may extend to ten years and shall also be liable to fine unless the woman raped is his own wife and is not under twelve years of age, in which case, he shall be punished with imprisonment of either description for a term which may extend to two years or with fine or with both: Provided that the court may, for adequate and special reasons to be mentioned in the judgment, impose a sentence of imprisonment for a term of less than seven years.