A Board may, with the approval of the Central Government, specify--
         (a) the powers and duties conferred or imposed upon the Board by or under this Act, which may also be exercised or performed by the Chairman; and
         (b) the powers and duties conferred or imposed on the Chairman by or under this Act, which may also be exercised or performed by the Deputy Chairman or any officer of the Board and the conditions and restrictions, if any, subject to which such powers and duties may be exercised and performed:
         Provided that any powers and duties conferred or imposed upon the Deputy Chairman or any officer of the Board under clause (b) shall be exercised and performed by him subject to the supervision and control of the Chairman.