JUDGMENT

VERMA, J.:— These appeals by special leave are by several industrial concerns against the Andhra Pradesh State Electricity Board (hereinafter called the Board) challenging the common judgment of the Andhra Pradesh High Court in writ petitions filed by these concerns challenging the revision of the electricity tariffs by the Board by its proceedings contained in B.P. Ms. No. 1014 (Commercial) dated 13-12-1983 which came into force on 15-1-1984. Prior to this revision, the tariffs were governed by B.P. Ms. No. 418 (Commercial) dated 12-1-1981. On 13-121983, two separate orders were issued by the Board revising the various tariffs. By one of them, namely, B. P. Ms. No. 1014, the tariffs for various categories of consumers including H.T. categories 1 and 11 were revised. By the other order of the same date, namely, Memo. No. DE/COML/IV/2250/83/I, the tariffs for high power intensive industries were also revised upwards. Out of the appellants, it was applicable to five units, namely, (1) Nav Bharat Ferro Alloys Ltd., (2) AndhraSugars Ltd., (3) Ferro Alloys Corporation Ltd., (4) Grindwell Norton Ltd., and (5) A. P. Carbides Ltd. This upwards revision of tariffs made by the Board