JUDGMENT A.N. Verma, J. - This bunch of petitions filed by various consumers of electrical energy supplied by U.P. State Electricity Board (hereinafter referred to as the Board) braises question as to the validity of the demand raised by the Board requiring the petitioner to deposit additional security. The petitions involve identical issues and are hence being disposed of by a common judgment. 2. The various petitioners entered into separate agreement with the Board for supply of electrical energy for industrial purpose. Under the agreement, Board contracted with the petitioners for the supply of electrical energy to them of varying loads subject to the conditions incorporated therein. One of the terms of agreement required the , petitioners to make a security deposit with ; the Board. The amounts of security deposited by the petitioners were worked out on the basis of rate schedule which was applicable at that time. In the agreement executed by some of the petitioners there was an express stipulation authorising the Board to demand additional security should the same become necessary. Subsequently, the rate schedules were revised, and, as a consequence, the Board raised the impugned demand for additional security from the petitioners. 3. Aggrieved by the demand for additional security deposit, the petitioners have approached this Court under Article 226 of the Constitution for quashing the same. In the petitions the main.ground of challenge was that there was no power in the Board to demand additional security either unilaterally or at all. In the course of oral submissions, however, additional points were urged which we will deal with later in this judgment. 4. The stand taken by the Board in the counter-affidavits filed on its behalf is that subsequent to the agreements executed by the petitioners rates for supply of electrical energy have been enhanced from time to time as a consequence of which the security deposits initially furnished by the consumers were rendered insufficient necessitating enhancement of the security deposits so as to secure the interest of the Board. The additional security deposits demanded by the Board has been worked out on the basis of the revised tariffs. It has been calculated on the basis of three months minimum consumption charges per KVA per month on the rates prevailing at present. The additional security deposits demanded by the Board has been worked out on the basis of the revised tariffs. It has been calculated on the basis of three months minimum consumption charges per KVA per month on the rates prevailing at present. The impugned demand is justified both under the express terms of the agreement executed by the petitioners in cases where the agreements contained a provision specifically entitling the Board to demand additional security deposits if found necessary as well as Cl. VI of the Schedule to the Indian Electricity Act 1910 read with S. 49 of the Electricity (Supply) Act 1948 and the regulations framed thereunder. Support has also been sought from the general term contained in all the agreements to the effect that the agreement shall be read and construed in all respects in conformity with all the provisions of the Indian Electricity Act, 19.10 and the Electricity (Supply) Act 1948 or any subsequent amendment thereof as well as the regulations made thereunder from time to time. It is also asserted in the counter-affidavit that in any case the agreements provide for resolution of all disputes arising between the Board and Consumers in regard to supply of electrical energy and the conditions imposed in respect thereof by the Board by means of arbitration and consequently the petitions are liable to be dismissed on the ground of alternative remedy being available for the petitioners which they have failed to exhaust before approaching this Court. 5. Having set o ut, in brief, the respective pleas of the parties, we proceed to consider the various submissions advanced on behalf of the petitioners as well as the learned counsel appearing for the Board. 6. For the petitioners the principal submissions set out below were advanced by Sri J.N. Tewari and Sri M. Katju, and the same have been adopted by the other learned counsel representing the various petitioners. In some petitions counsel raised additional points which will be dealt with after we have disposed of the main contentions. 7. Sri J.N. Tewari and Sri M. Katju submitted the following points for our considerations : - (i) The Board has no power to demand enhanced security deposit either unilaterally or at all. (ii) The demand for additional security is in any case arbitrary and is not based on any rational consideration. 7. Sri J.N. Tewari and Sri M. Katju submitted the following points for our considerations : - (i) The Board has no power to demand enhanced security deposit either unilaterally or at all. (ii) The demand for additional security is in any case arbitrary and is not based on any rational consideration. (iii) The provision for payment of only three percent interest on the security deposit made by the petitioners is violative of Article 14 of the Constitution of India, it having been fixed arbitrarily and is grossly unrealistic and illusory. 8. The first of these points is easily disposed of as the same is squarely covered "by a decision of the Supreme: Court in the case of Jagdamba Paper Industries (Pvt.) Ltd. v. Haryana State Electricity Board, AIR 1983 : SC 1296 which is directly in point. There the Supreme Court had occasion to consider a similar challenge in regard to an identical demand raised by the Haryana State Electricity Board. Repelling the challenge, ; their Lordships very categorically ruled that S. 49 of the Electricity (Supply) Act, 1948 (The 1948 Act, for short) clearly authorises the suppliers to demand additional security. Their Lordships held that under S. 49(1) the Board is authorised to determine the conditions such as it may deem fit on the ; basis of which supply of electricity is to be made. In the exercise of this power the Board is competent to revise conditions of electrical energy supply unilaterally. The demand for enhanced security for supply of electrical energy is, in their Lordships view, also a ; condition of supply. Their Lordships stated : the law in paragraph 7 of the report thus : - "We are of the view that the Board has ; been conferred with statutory power under S. 49( 1) of the Act to determine the conditions on the basis of which supply is to be made. This Court in Bisra Stone Lime Co. Ltd. v. Orissa State Electricity Board, (1976) 2 SCR 307 : AIR 1976 SC 127 took the view that .enhancement of rates by way of surcharge was well within the power of the Board to fix or revise the rates of tariff under the provisions of the Act. What applied to the tariff would equally apply to the security. that being a condition in the contract of supply. What applied to the tariff would equally apply to the security. that being a condition in the contract of supply. Each of the petitioning consumers had agreed to furnish security in cash for payment of energy bills at the time of entering into their respective supply agreements. There was no challenge in these writ petitions that the demand of security the time of entering into supply agreements has to be struck down as being without jurisdiction. Section 49(1) of the Act indicates that the Board may supply electricity to any person upon such terms and conditions as the Board thinks fit. In exercise of this power the Board had initially introduced the condition regarding security and each of the petitioners had accepted the term" (Emphasis supplied). 9. The above statement of the law provides a complete answer to the first point submitted by the learned counsel for the petitioner. It is significant to note that independently of whether the agreement executed by the petitioners specifically provided for demand of an enhanced security their Lordships of the Supreme Court recognised and upheld, the demand of the Board under the statute itself, namely, Section 49(1) of the 1948 Act on the ground that the power to impose such terms and conditions as the Board thinks fit for supply of electricity to any consumer includes and implies the existence of the power to demand an enhanced security deposit as a condition for supply of electrical energy. Even if, therefore, in the case of some of the petitioners, there was no provision specifically authorising the Board unilaterally to demand additional security, the latter could fall back on its basic rights under S. 49(1) of the Act and the regulations. The contrary opinion expressed by this Court in the case reported in AIR 1979 All 375 , (Modi Industries Ltd. v. U.P. State Electricity Board) has obviously been disapproved by the Supreme Court in the above decision. The opinion of the Andhra Pradesh High Court in the case reported in AIR 1979 Andh Pra 291 holding that the Board had power to demand enhanced security unilaterally was specifically approved by their Lordships in the same case. 10. Further in addition to Section 49, we have clause VI of the Schedule to the Indian Electricity Act 1910 which provides : "VI. Requisition for supply to owners or occupiers in vicinity .... 10. Further in addition to Section 49, we have clause VI of the Schedule to the Indian Electricity Act 1910 which provides : "VI. Requisition for supply to owners or occupiers in vicinity .... (1) where, (after distributing mains have been laid down under the provisions of Clause IV or Clause V and the supply of energy through those mains or any of them has commenced), a requisition is made by the owner or occupier of any premises situate within (the area of supply) requiring the licensee to supply energy for such premises, the licensee shall, within one month from the making of the requisition (or within such longer period as the (Electrical Inspector) may allow) supply, and, save in so far as he is prevented from doing so by cyclones, floods, storms other occurrences beyond his control, continue to supply, energy in accordance with the requisition : Provided, first that the licensee shall not be bound to comply with any such requisition unless and until the person making it - (a) within fourteen days after the service on him by the licensee of a notice in writing in this behalf, tenders to the licensee a written contract, in a form approved by the State Government, duly executed and with sufficient security, binding himself to take a supply of energy for not less than two years to such amount as will assure to the licensee at the current rates charged by human annual revenue not exceeding fifteen per centum of the cost of the service line required to comply with the requisition and (b) if required by the licensee so to do, pays the licensee the cost of so much of any service-line as may be laid down or placed for the purposes of the supply upon the property in respect of which the requisition is made, and if so much of any service line as it may be necessary for the said purposes to lay down or place beyond one hundred feet from the licensees distributing main, although not on that property : Provided, secondly, that the licensee shall be entitled to discontinue such supply - (a) if the owner or occupier of the property to which the supply is made has not already given security, or if any security given by him has become invalid or insufficient, and such owner or occupier fails to furnish security or to make up the original security to a sufficient amount, as the case may be, within seven days, after the service upon him of notice from the licensee requiring him so to do, or" (Emphasis supplied). ........................... ........................... "(3) Where any difference or dispute arises as to the amount of energy to be taken or guaranteed as aforesaid, or as to the cost of any service line or as to the sufficiency of the security offered by any owner or occupier, (or as to the position of the meter board) or as to the improper use of energy, or as to any alleged defect in any wires, fittings, works or apparatus, or to the amount of the expenses incurred under the third proviso to sub-cl. (1), the matter shall be referred to an (Electrical Inspector) and decided by him," (Emphasis added). 11. It will be seen that under the first proviso to Cl. VI the licensee (which in the present case is the Board in virtue of S. 26 of the 1948 Act) is empowered not to supply electrical energy to the consumer unless and until the consumer deposits security sufficient to protect the interest of the licensee in regard to its right to recover consumption charges as well as the costs of the service line etc. installed by it. The second proviso provides that the licensee shall be entitled to discontinue supply if it finds that the security given by the consumer has become insufficient or invalid. In the present case, the tariffs having been admittedly revised since the execution of the agreement, it is apparent that the security already furnished by the petitioners was rendered insufficient. Clause VI too, thus provides the source of power to the Board to demand additional security if it finds that the security already furnished by the consumer has become insufficient. 12. The next provision bearing on the point is S. 79 of the 1948 Act which authorises the Board to make regulations not inconsistent with that Act and the Rules made thereunder providing for various matters including principles governing the supply of electricity by the Board to persons other than licensees under S. 49 of the Act. In the exercise of this power, the Board has been framing regulations from time to time. In 1966 it framed regulations laying down the conditions of supply of electrical energy, Cl. 16 of which deals which the deposit of security by the consumer. In the exercise of this power, the Board has been framing regulations from time to time. In 1966 it framed regulations laying down the conditions of supply of electrical energy, Cl. 16 of which deals which the deposit of security by the consumer. The said clause in 'so far as is relevant to the issue provides : - "(i) Before giving supply, the supplier may require a consumer to deposit security in cash or through bank draft to safeguard recovery of electricity dues for the energy supplied to the consumer on credit. The rate of security deposit may be revised from time to time to take into account any change in tariffs and all existing consumers shall have to pay the additional security to replenish their security at the new rates of security deposit. No interest will be allowed on the deposit up to Rs. 100-00. Simple interest @ 3% per annum will be paid by the supplier on cash security deposit exceeding Rs. 100.00. Full calendar month only will be taken into account for purpose of calculating - interest. The interest accruing to the credit ; of the consumer for each period of 12 months ending 31st March will be adjusted in the electricity bill(s) arising subsequent to the said period. (ii) The Board will beat liberty at any time to further raise the security from consumers who habitually default in making payments of their monthly dues. (iii) The Supplier shall be at liberty to apply at any time any security deposit made by a consumer towards payment or satisfaction of any money which may become due and payable by him to the Supplier. In all such cases, the consumer will be required to make up the deficiency so caused in his security deposit and he shall be liable to disconnection, without any further notice, if he fails to comply within seven days from date of service of the notice on him asking him to make up the deficiency. The connection of the consumer shall be reconnected only after he pays the amount deficient in the security and the requisite charges for the disconnection/reconnection as enforced by the Supplier from time to time. The connection of the consumer shall be reconnected only after he pays the amount deficient in the security and the requisite charges for the disconnection/reconnection as enforced by the Supplier from time to time. (iv) The supplier may, at his discretion, demand additional security from a consumer at any time and the consumer shall be bound : to pay the same within the time stipulated in the demand, failing which the consumer shall be liable to disconnection. Reconnection of the supply in such a case will be made by the Supplier only after the receipt of disconnection/reconnection charges and the additional security as demanded. (v) The departments of the Central Government the State Government and the Indian Railways shall be exempted from security deposit." (Emphasis added)(Not added in copy - Ed.) 13. Clause 17 of the aforesaid regulations lays down that the consumer shall enter into a formal agreement for taking electrical energy before release of supply. It states that all consumers shall execute agreements governing supply of energy in the form prescribed by the Board from time to time. 14. We have then Cl. 18 which provides :- that the charges for supply of electrical energy shall be in accordance with the tariff as may be in force from time to time. 15. It will thus be seen that the regulations which have undeniably statutory force specifically authorise the Board to demand additional security from a consumer at any time and the consumer is obliged to pay the same within the time stipulated in the demand failing which the Board is entitled to disconnect supply of electrical energy to the consumer. Equally undeniably these provisions lay down but a condition of supply of electrical energy within the meaning of S. 49 of the Act. 16. The model conditions prescribed under S. 27 of the 1910 Act also indicate the existence of such a power in the Board. Clause 14 of the model conditions laid down in Annexure 6 to the Rules framed under the 1910 Act provides : - 14. Security Deposit - The licensee may require any consumer to deposit security for the payment of his monthly bills for energy supplied and for the value of the meter and other apparatus installed on his premises.No interest will be allowed on deposits up to Rs. 25/-. Security Deposit - The licensee may require any consumer to deposit security for the payment of his monthly bills for energy supplied and for the value of the meter and other apparatus installed on his premises.No interest will be allowed on deposits up to Rs. 25/-. Interest at the rate of - per cent per annum will be paid by the licensee' on deposits exceeding Rs. 25/-. The licensee shall be at liberty at any time to apply any security deposited towards payment or satisfaction of any money which shall become due or owing by the consumer. The licensee shall also be at liberty to demand enhanced security deposit from consumers at any time during the life of the contract. The balance of the security deposit will be returned to consumer on the termination of the contract. The consumer may, at any time, with the previous consent of the licensee, transfer the contract and its liabilities to any o there person approved by the licensee." 17. Incipiently, this clause also discloses the object and the purpose for which security is insisted on by the Board. It lays down that the licensee shall be at liberty at any time to apply any security deposited towards the payment or satisfaction of any money which shall become due or owing b y the consumer. 18. A survey of the statutory provisions analysed by us here in above thus leaves no manner of doubt that there is more than ample support in the statutory provisions for the demand of additional security by the Board. It is not disputed that by means of an Office Memorandum issued on 19-3-83, a true copy of which has been annexed to the Writ Petition No. 9922 of 1983, rates of security applicable to various categories of consumers were revised consequent upon an upward revision in the tariffs. It was also not disputed by the petitioners that the additional security demanded by the Board from them has been worked out in accordance with the rate schedule disclosed in the said office Memorandum. In the counter-affidavits, which have been filed on behalf of the Board, it has been repeatedly asserted that the rates of security were revised under the aforesaid Office Memorandum as a direct sequel to an escalation in the tariffs. In the counter-affidavits, which have been filed on behalf of the Board, it has been repeatedly asserted that the rates of security were revised under the aforesaid Office Memorandum as a direct sequel to an escalation in the tariffs. It also has been asserted that the additional security has been calculated on the basis of three months' minimum consumption charges per KVA per month on the rates applicable at the relevant time. The Board has been specifically authorised both under Section 49 of the 1948 Act and the regulations framed thereunder to re-frame tariffs and minimum consumption charges. The petitioners did not seriously challenge the assertion of the Board that since the agreements were first executed by them minimum charges have gone up. 19. Some of the learned counsel, however, submitted that in the absence of any clause in the agreements executed by the consumers authorising the Board to demand an enhanced security, it is not competent to the latter to make the impugned demand. 20. The contention is devoid of any merit The agreements in question contain an express stipulation that the same shall be read and construed in all respects in conformity with all the provisions of the 1910 Act and the Electricity (Supply) Act 1948 or any subsequent amendments made therein and any regulations made thereunder from time to time. The agreements have thus to be read consistently with the provisions of the Supply Act 1948 and the regulations framed thereunder. In our opinion, unless there is a special agreement providing for special tariffs entered into under sub-sec. (3) of S. 49 of the 1948 Act, the agreement cannot be read in derogation of the statutory provisions. The statutory provisions in the event of a conflict override the agreement. Further we find no inconsistency between the agreement and the regulations providing for enhanced security. The agreements do not stipulate that it will not be open to the Board to demand enhanced security even if the Board finds the security originally deposited by the consumer to have been rendered insufficient by reason of escalation in the tariffs for securing the payment of which the consumers are called upon to furnish security. Still further we find that according to their Lordships of the Supreme Court in the decision cited above the power to challenge enhanced security flows basically from Section 49. 21. Still further we find that according to their Lordships of the Supreme Court in the decision cited above the power to challenge enhanced security flows basically from Section 49. 21. In this connection, learned counsel also submitted that in some of the agreements which specifically authorised the Board to demand additional security subject to certain terms and conditions specified therein, unless the Board establishes the existence of those conditions, it could not fall back on the agreement for making a demand for additional security. This submission has no bearing on the general argument that the Board has no power whatever to demand additional security. It implies a challenge to the quantum of the security demanded rather than the authority of the Board to make such a demand. In any case, as found above, the regulations mentioned above authorising the Board to make the impugned demand provide a complete answer to the submission. 22. We next turn to the Second submission which too, in our opinion, has no merit. The Board has indicated the basis on which it has worked out the additional security deposits demanded by it from the various petitioners. Shortly, the stand taken by the Board in the counter-affidavit is that the additional security has been worked out on the basis of three months' minimum consumption charges per KVA per month, on the rates prescribed by the office Memorandum of March 83, for varying categories of consumers. In exercise of its powers under S. 49 of the 1948 Act, the Board had revised the tariffs upward and as a direct consequence the minimum consumption charges per KVA also increased since the agreements were signed by the consumers initially. The security initially deposited by the consumers was thus inevitably rendered insufficient. 23. The Board has also explained in its counter-affidavit the methodology adopted by it in working out the additional security. It is asserted that normally meter reading is done after 30 days and it takes nearly 15 to 20 days to prepare the bills and in issuing the same to the consumers. A further period of 15 days is allowed to the consumer from the date of the issue of the bill to make payment. Seven days notice of disconnection after expiry of due dates is also given to the consumer for non-payment of the bill. A further period of 15 days is allowed to the consumer from the date of the issue of the bill to make payment. Seven days notice of disconnection after expiry of due dates is also given to the consumer for non-payment of the bill. Thereafter, it takes two to three days to verify the payment or otherwise of a particular bill. The Board has, therefore, adopted uniform yardstick of demanding additional security on the basis .of three months .consumption charges calculated at the minimum consumption charges leviable per KVA of the contracted load. 24. The assertion of the Board finds support from Cl. 19 of the 1966 Regulation mentioned above which lays down the mode of payment of bills. From the procedure laid down in that clause, the inference drawn by the Board that in a large majority of cases there is generally a gap of three months between the actual consumption of the electrical energy and the payment seems logical and fully justified. It is based on common practice or experience and the procedure statutorily prescribed for the recovery of consumption charges from the consumers. The stand taken by the Board in this connection cannot therefore be characterised as arbitrary or unjust. It may also be mentioned here that the Supreme Court had also occasion to consider the validity of a similar yardstick adopted by the Haryana State Electricity Board in support of its claim for additional security. There also the Board had worked out the demand on the same basis. Their Lordships approved the same as valid and proper not calling for any interference by Courts. In this view of the matter', we find no merit in the second submission also. 25. Sri J.N. Tewari, however, with the help of a solitary bill in respect of a consumer, namely, Hindustan Chain Private Ltd. made an attempt to argue that according to the current practice and the period within which the bill has to be cleared by the consumer, security should be calculated only on the basis of two months minimum consumption charges and not three months as adopted by the Board. We cannot agree. We cannot agree. In our opinion, the yardstick adopted by the Board is based on a practice which generally prevails in a large majority of cases and we have found no valid ground or material which may lead to the conclusion that the yardstick adopted by the Board is ex facie excessive or arbitrary. The second submission, therefore, also fails. 26. Before we pass on to the third submission, we propose to dispose of a few additional points canvased by some of the learned counsel. 27. Sri O.P. Agarwal appearing for the petitioner in Writ Petition No. 10438 of 1983 submitted that some of the petitioners in this case had earlier filed another petition in this court being Writ Petition No. 2837 of 1976 which was decided on 16-5-1979. A similar demand as the one which is the subject matter of the present petition for enhanced security was quashed by this Court by its judgment dated 16-5-1979 and although the respondent Board filed an appeal against that decision and special leave petition was granted to it by the Supreme Court sometime in 1982, the decision of the High Court continues to bind the Board and operates as res judicata. 28. We find the submission wholly unacceptable. The earlier petition was concerned with a demand raised in 1975 i.e. prior to the enforcement of the new rates of security by the respondent Board based on its office Memorandum issued in March 1983. The present petition is based on a fresh demand arising from security rates schedule fixed subsequently to the decision in the earlier petition. The causes of action in the two petitions are thus distinct and different. The earlier decision of this Court would operate as res judicata against the Board only in so far as the particular demand which was impugned in that petition was concerned. It cannot, in our considered view, debar the Board from raising fresh demand based on a revision of rates of security. 29. Sri O.P. Agarwal next submitted that the decision of the Supreme Court in the case of Jagdamba Paper Industries Pvt. Ltd. ( AIR 1983 SC 1296 ) (supra) was rendered in June 1983 whereas the impugned demand was raised in pursuance of the Office Memorandum issued by the Board in March 1983 prior to the decision of the Supreme Court. That being so. That being so. it was urged, the decision of the Supreme Court would govern only those cases where the demand was raised after the decision of the Supreme Court. The submission is completely devoid of any merit. The fact that decision of the Supreme Court came in June 1983 does not imply that the law declared by it would be effective only from the date of decision. The Supreme Court merely interpreted the statute which remained the same. It was not as though as a result of the decision of the Supreme Court any change in the statute was brought about. 30. Reliance was also placed by the learned counsel on the decision of the Supreme Court reported in AIR 1975 SC 1967 which lays down that the special tariff fixed by the Board under sub-sec. (3) of S. 49 cannot be unilaterally altered by the Board. 31. That decision has obviously no application. For, the present is not a case where the petitioners may have entered into any special agreement such as is contemplated under sub-sec. (3) of S. 49. Petitioners have not established that in their case the Board had fixed any special tariffs different from the uniform tarries fixed by the Board, under sub-secs. (1) and (2) of S. 49. 32. Finally we take up the third and the last point that relating to the quantum of interest payable on the security deposits by the Board. On this point the main submissions were addressed by Sri Katju. His argument may be summarised thus. The security deposits are monies held in trust with the Board for due payment of electricity charges. They are not in their very nature intended to be utilised by the Board for augmenting its capital resources. Any interest earned thereon must, therefore, be passed on in toto to the consumers. The second limb of this submission was that the payment of only 3% as interest has been arbitrarily fixed by the Board and is wholly illusory and is not based on any rational premise. 33. This submission also, in our opinion, cannot be accepted. For a proper appreciation of the submissions of the learned counsel it will be necessary to examine closely the precise nature and purpose of these deposits. 33. This submission also, in our opinion, cannot be accepted. For a proper appreciation of the submissions of the learned counsel it will be necessary to examine closely the precise nature and purpose of these deposits. Clause (6) of Schedule VI of 1910 Act requires a licence to deposit sufficient security and under the second proviso it authorises the licensee to demand additional security in case the original security is at any time found to have become insufficient. What is sufficient security is disclosed by clause 16 of the 1966 Regulations and the model conditions referred to above which state that the Board may require a consumer to deposit security as mentioned in those regulations for the payment of charges for energy supplied and for the value of the meter and other apparatus installed at his premises. It will thus be seen that the deposit is primarily intended to secure to the Board the payment of charges for electrical energy supplied as well as for the value of the meter and other apparatus installed at the consumers' premises. 34. Put in different words, the security deposit is primarily and solely intended to protect and secure the interest of the Board in regard to its claim for recovery of electrical dues from the consumers as well as for indemnifying itself against possible losses arising from the damage caused to its installations by the consumer. And this right the Board may be called upon to exercise at any time as soon as it finds that the consumer is in default or has caused damage to its installations or apparatus as neither the agreement executed by the consumer nor the regulations prohibit the Board from exercising its right to proceed against the security before the expiry of any stated time. The Board cannot hence reasonably be expected to invest these security deposits in any long term interest bearing accounts so as to secure greater returns to the consumers. The liquidity of these security deposits has to be maintained at all times so that the Board is not drawn into endless legal battles in courts so as to recover the dues. Power generation is an essential service. The Board can, therefore, ill-afford to launch itself on the consuming processes of law and launch itself on litigation to recover consumption charges. Power generation is an essential service. The Board can, therefore, ill-afford to launch itself on the consuming processes of law and launch itself on litigation to recover consumption charges. The submission, therefore, that the Board is under some kind of obligation cast on it by the Constitution to invest the security deposits furnished by the consumers into some interest bearing channels so as to secure greater returns than 3% currently allowable to the consumers cannot hence be accepted. 35. A security deposit is by the nature different from usual deposits in banks or : companies for fixed terms. Both in legal and , commercial parlance security simply means 'protection', 'assurance' or indemnification and is basically intended to provide the creditor with a resource which he might use ; in case of the debtor's failure to fulfil his obligations. This is how the term has been defined in Black's Law Dictionary. Vth Edition, at page 1216 : "Security-protection, assurance; in-deification. The term is usually applied to an obligation, pledge, mortgage, deposit, lien, etc. given by a debtor in order to assure the payment or performance of his debt, by furnishing the creditor with a resource to be used in case of failure in the principal obligation. Document that indicates evidence of indebtedness. The name is also sometimes given to one who becomes surety or guarantor for another." 36. In 'Words and Phrases' Permanent Edition, Volume 38 also the definition of the term is the same. It states : "Security" is something which makes the enjoyment or enforcement of a right more secure or certain; that which secures or makes safe. In re New York Title & Mortgage Co. 289 N.Y.S. 771, 785, 160 Misc. 67." The term security' signifies that which makes secure or certain. In its proper use it relates to pecuniary matters, and often consists of a promise or right unattended.with possession of the thing upon which it reposes, it implies in its common acceptation that which prevents loss or makes safe." 37. It is unnecessary to burden the judgment further with how the term security has been defined in various other legal dictionaries as the basic concept as speller out in each of these dictionaries is the same, namely, that it is money deposited with the creditor by a debtor in order to assure the payment or performance of his debt. It is unnecessary to burden the judgment further with how the term security has been defined in various other legal dictionaries as the basic concept as speller out in each of these dictionaries is the same, namely, that it is money deposited with the creditor by a debtor in order to assure the payment or performance of his debt. It is a resource which the creditor may use in case the debtor fails to fulfil his obligations. In the present case the security deposit has been worked out on the basis roughly of three months minimum consumption charges. The actual charges may in many cases exceed by far the minimum consumption charges. And as mentioned above, the deposit is intended to secure both the payment of consumption charges as well as towards protecting the Board against damage which may be caused to its installations or apparatus etc. within the premises of the consumer. 38. It will thus be seen that the security deposits are not intended to swell the general revenues of the Board or to augment its capital resources. The assumption that it is being mis-utilised or is being used for a purpose other than keeping it as a resource which may be readily available to it for the satisfaction of its monetary claims, such as, consumption charges, etc., has remained totally unsubstantiated. The further assumption that the Board has been making profits or is earning greater interest thereon than it is passing on to the consumers, has also not been established with reference to any concrete material. 39. As regards the submission of the learned counsel that these monies are held by the Board in trust for and on behalf of the consumers and that the Board is in relation to those deposits in fiduciary capacity also does not advance the case of the petitioners further. For, even assuming that the Board occupies vis-a-vis the consumers the position of trustee, there is nothing to indicate that it has, by agreeing to give only 3% interest to the consumers, committed any breach of the trust or has failed to fulfil its obligations arising out of such a supposed trust. 40. For, even assuming that the Board occupies vis-a-vis the consumers the position of trustee, there is nothing to indicate that it has, by agreeing to give only 3% interest to the consumers, committed any breach of the trust or has failed to fulfil its obligations arising out of such a supposed trust. 40. Sri M. Katju relying on the case of Ramana Dayaram Shetty v. International Airport Authority of India and reported it AIR 1979 SC 1628 vehemently contended that even if the contracts between the consumers and the Board are commercial in character and even if the statutory regulations provide for payment of only 3% interest to the consumers, Article 14 of the Constitution obliges the Board to Act just and fairly in its dealings with the consumers. It was urged that the Board cannot unilaterally fix the rate of interest at 3% at its sweet will like a private creditor. It must, contended the learned counsel, in all fairness invest the amounts in banks and other financial institutions guaranteeing payment of higher interest to the consumers. 41. The submission though attractive on its face does not bear a closer scrutiny. It ignores the true nature of these security deposits. As mentioned above, the Board does not know at what point of time it may have to fall back on this security for satisfying its claims in money outstanding against the consumers. The security deposits are equivalent to only three months' minimum consumption charges and it is not infrequently that the Board has to take resort to these security deposits for satisfying its dues. The Board cannot hence be expected to invest these security deposits in some long term fixed deposits bearing higher rates of interest. 42. Further, Sri S.C. Verma, learned counsel for the respondent Board produced before us a chart, the correctness of which was not challenged by the learned counsel for the petitioners, showing the rates of interest payable on security deposits by the State Electricity Board of various States of the country. In many States, like Assam, Gujarat, Orissa and Rajasthan no interest is at all payable on these deposits. Andhra Pradesh and Kerala are paying on these deposits. Andhra Pradesh and Kerala are paying the same amount of interest as the respondent Board, namely, 3%. Some States like Delhi are paying less than 3%. 43. In many States, like Assam, Gujarat, Orissa and Rajasthan no interest is at all payable on these deposits. Andhra Pradesh and Kerala are paying on these deposits. Andhra Pradesh and Kerala are paying the same amount of interest as the respondent Board, namely, 3%. Some States like Delhi are paying less than 3%. 43. On the material brought on the record before us, therefore, it is impossible to conclude that the rate of interest allowable on the security deposits in Uttar Pradesh is arbitrary or illusory or has been fixed without having any rational basis in support thereof. 44. Sri Navin Sinha appearing in writ petition No. 8513 of 1983, submitted' an additional point in support of this argument, He pressed in aid the doctrine of unjust enrichment. He placed reliance on Chitty on Contracts and submitted that any interest earned by the Board on security must be passed on to the consumers irrespective of what may be the rate of interest prescribed. It was urged that the Board cannot, in view of this equitable principle keep back the amount in interest in excess of 3% with it. We regret our inability to accept this submission. The principle of unjust enrichment has no application whatever to the facts of the present case. The doctrine is attracted only when it is demonstrated that the amount has been deposited or paid under a mistake or upon a consideration which happens to fail or for money procured through imposition (express or implied) or extortion or oppression or undue advantage taken of the creditors situation, contrary to the laws made' for the protection of persons under those circumstances (see Chitty on Contracts, 24th Edn. para 1787). 45. In this connection, it will be pertinent to notice a submission of Sri S.C. Verma, learned counsel for the respondent Board which, in our view, has considerable merit. He rightly urged that this Court ought not to entertain an argument as regards the rate of interest fixed under the Regulations in as much as under Cl. 25 of the Regulations a machinery is provided for resolving any difference or dispute arising between the supplier and consumer in respect of any matter connected with the supply by way of a reference to the Electrical Inspector. 25 of the Regulations a machinery is provided for resolving any difference or dispute arising between the supplier and consumer in respect of any matter connected with the supply by way of a reference to the Electrical Inspector. There can be little doubt that the argument raised by the learned counsel for the petitioner as regards the rate of interest is a matter connected with the supply of electrical energy and is hence capable of being resolved by way of arbitration as provided both under the agreement as well as under clause 25 of 1966 Regulations. In any case, on the material placed before us, we are not satisfied that the regulation providing for payment of 3% interest on security deposits suffers from any illegality or infraction of any constitutional rights of the petitioners. 46. In conclusion, we hold that the provision for payment of 3 per cent interest of the security deposit is neither violative of Article 14 of the Constitution nor is it unreasonable or arbitrary. 47. Th& facts of writ petitions Nos. 3405 and 3411 of 1980 are slightly different from the rest of the bunch though the ultimate conclusion in respect of these two is the same as in the remaining petitions. In both these cases, the petitioners had challenged by means ; of writ petitions Nos. 673 and 662 of 1972 [similar notice of demand for additional security issued by the respondent Board in 1975 on the ground that it had no power to claim additional security over and above that deposited at the time of the execution of the agreement. The contention of the petitioners was upheld by this Court by its judgment dated April 6, 1979 and the impugned notices were quashed. The decision is reported in the case of Modi Industries Ltd. (AIR 1979 SC 375) (supra). After that decision, the Board terminated the agreement and required the petitioners to enter into a fresh agreement which contained a stipulation for deposit of security for a higher amount as was demanded under the original agreement. The petitioners immediately thereafter filed these petitions challenging the demand for additional security contemplated under the fresh agreement. In the counter-affidavits the stand taken is that the petitioners have since executed the agreement and under the interim orders passed by this court furnished bank guarantees for the additional security demanded by the Board. 48. The petitioners immediately thereafter filed these petitions challenging the demand for additional security contemplated under the fresh agreement. In the counter-affidavits the stand taken is that the petitioners have since executed the agreement and under the interim orders passed by this court furnished bank guarantees for the additional security demanded by the Board. 48. In these two petitions, Sri Vishnu Sahai advanced an additional argument which was that the impugned demand for additional security is barred by res judicata in view of the previous decision of this court ,the earlier petitions mentioned above. It was urged that the decision of this court holding that the Board has no power to demand additional security even if it runs counter to the subsequent decision of the Supreme Court would continue to govern the relations between the parties so long as that decision is not set aside by the Supreme Court. 49. We find it difficult to accept the contention. It is not disputed that after the decision of this Court the petitioners entered into fresh agreements providing for an enhanced security. It is also admitted that the subject matter of the present petition is a fresh demand raised under the new agreement. The causes of action in the two petitions are, in our opinion, clearly different and distinct. The previous decision will operate as res judicata only in so far as the demand raised under the notices issued by the Board in 1975 which were quashed by this Court was concerned and not in regard to fresh notices issued by the Board under the new agreements. In considering the validity of the fresh notice of demand, therefore, this court is free to follow the decision of the Supreme Court rendered in AIR 1983 SC 1296 (supra). The Supreme Court specifically noticed the view of this Court reported in AIR 1979 All 375 as well as the contrary view expressed by the Andhra Pradesh High Court in the case reported in AIR 1979 Andh Pra 291, Kishna Cement Works v. Secretary, A.P.S.E.B. Their Lordships of the Supreme Court quoted the following passage from the judgment of the Andhra Pradesh High Court and approved the same in preference to the view expressed by this Court. "To our mind, this is a quite satisfactory explanation of the reasons behind insistence on cash security. "To our mind, this is a quite satisfactory explanation of the reasons behind insistence on cash security. Certainly a public utility service like Electricity Board cannot launch itself on litigation to recover consumption charges on a large scale. Power generation, which it does is an essential service and that shall never be allowed to suffer on account of improper security. We have already referred to the fact that it is reasonable on the part of the Board to require security for three months consumption charges. Now to require that amount to be deposited in the form of cash is eminently reasonable." 50. For the reasons given above, these two petitions are also liable to be dismissed. 51. Sri V. B. Singh appearing for some of the petitioners cited a few decisions in support of his contention that Article 14 of the Constitution is attracted also in areas where the State enters into commercial transaction with private individuals. It is unnecessary to dilate on this submission as, in our opinion, the validity of the impugned demand can be upheld on the basis of the statutory provisions noticed by us quite independently of the rights of the Board under the agreement. 52. In the result the petitions fail and are dismissed with costs. The interim orders issued by this Court are hereby vacated. The: respondent Board shall be at liberty to en-cash the bank guarantees furnished by the petitioners for satisfying its claim for additional security.