(a)the Central Government,–(i)in respect of a generating company wholly or partly owned by it;(ii)in relation to any inter-State generation, transmission, trading or supply of electricity and with respect to any mines, oil-fields, railways, national highways, airports, telegraphs, broadcasting stations and any works of defence, dockyard, nuclear power installations;(iii)in respect of National Load Despatch Centre and Regional Load Despatch Centre;(iv)in relation to any works or electric installation belonging to it or under its control;