(1) It shall be the duty of the Vice-President of every Board,--
         (a) in the absence of the President and unless prevented by reasonable cause, to preside at meetings of the Board and when so presiding to exercise the authority of the President under sub-section (1) of section 21;
         (b) during the incapacity or temporary absence of the President or pending his appointment or succession to perform any other duty and exercise any other power of the President; and
         (c) to exercise any power and perform any duty of the President which may be delegated to him under sub-section (2) of section 21.