P. SATHASIVAM, J.

As common questions of law and fact arise in this group of appeals, they were heard together and are being disposed of by the following Common Judgment. Writ appeal No. 74/95 is by one Shanmugaraja Spinning Mills Private Limited against the order of the learned Judge dated 31-8-94 in Writ Petition No. 5588 of 86. Writ Appeal No. 421 of 95 is by Kothari Industrial Corporation Limited, Madras-34 against the order of the learned Judge dated 6-4-95 in W.P. No. 12017 of 88. Writ appeal No. 488 of 95 is by Messrs. National Oxygen Limited, Madras-10 against the order of the learned Judge dated 6-4-95 in Writ Petition No. 11661 of 84. Writ Appeal No. 1486 of 95 is by Sree Visalakshi Mills Private Limited, Manalur, against the order of the learned Judge dated 17-4-95 passed in W.P. No. 575 of 90. Writ Appeal No. 10 of 96 is by Messrs. Sambandam Textiles Private Limited, Salem, against the order of the learned Judge dated 14-3-95 in Writ Petition No. 12095 of 85. All these writ petitions filed by the appellants herein were dismissed by the learned Judge (J. Kanakaraj, J.) confirming the action of the Tamil Nadu Electricity Board/Government in claiming consumption charges from the respective concerns.

2. For convenience, we shall refer the parties as described in the writ petitions. The case of the appellant in Writ Appeal No. 74 of 95 petitioner in W.P. No. 5588 of 86 is briefly stated hereunder :-

The petitioner is a private limited company, incorporated on 27-8-1980 with the object of running a spinning Mill. It has set up a spinning Mill at National Chittode, Erode District. They applied to the second respondent for supply of H.T. electricity. The second respondent by his communication dated 6-1-82, accorded sanction for supply of H.T. electricity up to 500 K.V. to the petitioner. Power supply was effected on 23-2-84. On 6-1-82, when the second respondent sanctioned supply, the tariff rates were governed by G.O.Ms. No. 1487, Public Works (Electricity) dated 9-10-74. That Government Order passed under Tamil Nadu Act 1/1979 provide for concessional rates of supply for new industries for 5 years after commencement of production. While so, the Government of Tamil Nadu passed another order in G.O. 861, Public Works, Electricity dated 30-4-82, which also provide for concessional rates of power supply. It also provide for concessional rate of power tariff. In this latter Government Order, there was a condition that the concessional rate would not apply from the year when the industry starts earning profits. In 1984, the petitioner was required by the first respondent to sign an undertaking prepared by the first respondent for the extension of concessional rates. The undertaking stated that the petitioner had taken note of G.O. No. 861, Public Works dated 30-4-82 which specified that concessional rates would not be available for the year when the industry starts earning profits. It also required the petitioner to reimburse the Board in lump sum the concession allowed after expiry of 6 months from the end of accounting year or after finalisation of accounts in case the industry is found to have earned profits. The petitioner signed the undertaking on 8-5-84. In 1985 also, the petitioner gave a similar undertaking to the second respondent. They also accepted the balance-sheet and profit and loss account for the year ended 31-3-85. However, on 16-6-86, the petitioner received a communication from the first respondent stating that tariff concession at 66 per cent had been allowed for the years 1984-85 and 1985-86 based on the undertaking furnished by the petitioner. The balance-sheet produced in October, 1985 showed that the industry had earned profits. For ascertaining profits in a year only the profit and loss account had to be taken into account and the accumulated loss of previous years should not be brought forward. On this analogy, the petitioner had earned a profit of Rs. 1, 06, 399/- during 1984-85. The first r