In this Act, unless the context otherwise requires,—

(a) “competent authority” means any person or authority authorised by the Central Government, by notification in the Official Gazette, to perform the functions of the competent, authority under this Act and different persons or authorities may be authorised to perform all or any of the functions of the competent authority under this Act in the same area or different areas specified in the notification;

(b) “corporation” means any body corporate established under any Central, Provincial or State Act, and includes—

(c) “petroleum” has the same meaning as in the Petroleum Act, 1934, and includes natural gas and refinery gas;

(d) “prescribed” means prescribed by rules made under this Act.