1. As common questions of law are involved on similar set of facts, all these writ petitions are heard together and are being disposed of by this common order. For the purpose of disposal, I refer to the facts as arise in WP No.31962 of 2012.

2. The writ petition in WP No.31962 of 2012 is filed seeking directions by way of mandamus, to declare Letter No. SE/OP/RRRN/SAO/JAO-HT/D.No.365, dated 22.6.2012, issued by the Superintending Engineer of Central Power Distribution Company of A.P. Limited, as illegal, with consequential declaration that; (1) the petitioner is entitled to interest at the rate of 9.5% per annum, with effect from 13.2.2012, on the security deposit lying with the respondents and (b) that the respondents shall pay interest at twice the rate specified in clause 7(1) i.e., at the rate of 19% per annum with effect from 13.2.2012, till they actually pay the interest for the consumption years 2011-12 and 2012-13.

3. Petitioner is a Company having its industrial unit at Plot Nos.8, 11B, 12C and 12D of IDA Phase-III, Jeedimetla, Hyderabad and is engaged in the business of manufacturing iron and steel products. For the purpose of running the Unit, the petitioner had obtained HT power supply from the erstwhile Andhra Pradesh State Electricity Board. Prior to the year 1998, the law relating to production and supply of electric power was principally governed by the provisions under the Indian Electricity Act, 1910 and the Electricity (Supply) Act, 1948. The Andhra Pradesh State Electricity Board was constituted and it was looking after the generation, transmission and distribution of power. The State of Andhra Pradesh has enacted A.P. Electricity Reforms Act, 1998, separating the Companies with regard to generation and transmission and created Generation Company of A.P. Ltd. i.e., A.P. GENCO and the Transmission Company of A.P. Ltd. i.e., A.P. TRANSCO. Under the very Act, several other Companies are formed to look after the distribution of power and such Companies are the licensees under the Act. Thereafter, the A.P. Electricity Regulatory Commission (Security Deposit) Regulation, 2004 (Regulation No.6 of 2004) was framed. As per the said regulation, all the consumers have to deposit the sum equivalent to two months consumption charges towards security deposit/consumption deposit. Such deposit is to be reviewed by the licensee from time to time. Clause 7 of the aforesaid regulation reads as under :

"7. Interest on Security Deposit Payable by the Licensee.- (1) The licensee shall pay interest on security deposit of a consumer, at the Bank rate notified by Reserve Bank of India provided that the Commission may specify a higher rate of interest from time to time by notification in Official Gazette.

(2) The interest accruing to the credit of the consumer shall be adjusted annually against the amounts outstanding from the consumer to the licensee as on 1st May of every year and the amounts becoming due from the consumer to the licensee immediately thereafter.

(3) The licensee shall duly show the amounts becoming due to the consumer towards interest on the security deposit in the bills raised on the consumer.

(4) The licensee shall pay interest at twice the rate specified under sub-clause (1) above for the delay in making the adjustments for interest on security deposit."

On the deposit made by the petitioner, respondents were paying interest at the rate of 6% per annum, which was the bank rate of interest notified by the Reserve Bank of India. The Reserve Bank of India has revised the bank rate of interest with effect from 13th February 2012 from 6% to 9.5% per annum, in exercise of powers under Section 49 of the Reserve Bank of India Act, 1934. In view of revision of the bank rate of interest as notified by the Reserve Bank of India, the petitioner has made a representation dated 4.6.2012, for revising the rate of interest from the said notified date and to adjust such amount in the bills. A further letter dated 20th