Mr. Raj Malhotra, learned Senior Counsel appearing on behalf of the appellant would submit that the Division Bench of the High Court committed a serious error in passing the impugned judgment insofar as it failed to take into consideration the importance of holding a physical test before preparation of the select list. The learned counsel urged that arbitrariness on the part of the Selection Committee is apparent from the fact that the order of holding tests was pushed to the background. It was furthermore submitted that the Division Bench of the High Court did not assign sufficient and cogent reasons for interfering with the well considered judgment of the learned Single Judge and proceeded to modify the same without any application of mind. Our attention was moreover drawn to the fact that the purported reasons for modification, which were enumerated in paragraph of the impugned judgment, really contain the statement of facts and thus the same is wholly unsustainable. Mr. P.K. Goswami, learned Senior Counsel appearing on behalf of the private respondents, on the other hand, would contend that the appellant, in the facts and circumstances of this case, must be held to be estopped and precluded from raising any contention with regard to the validity or otherwise of the procedure for selection adopted by the Selection Committee as he had participated in the selection process without any demur whatsoever. It is stated that pursuant thereto and in furtherance thereof only the said respondent had been appointed and had been working since then. Our attention was furthermore drawn to the fact that against the order of the leamed Single Judge, a writ appeal had been filed by him, which is pending. Indisputably in the advertisement, the candidates were required not only to qualify in the written test but also the physical ability test. A plain reading of the advertisement clearly goes to show that the interview was to be conducted only after holding of the said two tests. In tune with the said require merits only, the candidates were asked to appear in the written test on 26.04.1998 and in the physical test on 28.04.1998. There cannot, however, be any doubt whatsoever that a Selection Committee in a given situation, may lay down a procedure for the purpose of short listing the candidates but that does not mean that for the said purpose, the order of holding a requisite test would be changed. In terms of a decision, which was taken on 07.04.1999, the Selection Committee thought to take interview prior to holding of the physical ability test. Physical ability test keeping in view the nature of the job required to be performed by the candidates was an extremely important one. Passing in the physical ability test is a sine qua non for selection of the candidates in the post of Sub-Inspector of Police. It was indeed a competitive test and the merit list should have been prepared not only on the basis of the written test and interview but also the physical ability test. The Selection Committee, in our opinion, committed a serious error in changing the order of holding the tests. The learned Single Judge, therefore, was correct in arriving at a conclusion that physical ability test should have been held prior to holding of the interview. The Commission contends that the manner of conducting examination by the Commission even in regard to recruitment to Judicial Service, is governed by the Uttar Pradesh Public Service Commission Rules, 1976 made by the Commission in exercise of the power conferred by the UP State Public Service Commission Act, 1974. Rule 26 provides for preparation of a panel of Examiners or constitution of a committee for the purpose of holding examination in each subject. Rule 28 provides that the question papers set by the examiners shall be placed before the Commission to ensure conformity with the required standard of examination and the Commission may moderate the question papers or constitute a Committee to perform the work of moderation. Rule 30 provides for advertisement of vacancies for which selections are to be made and scrutiny of applications received. Rule 33 provides for the determination of place, dates and time of examination and the centres for examination. Rule 34 provides for the list of persons suitable to be appointed as invigilators and appointment of invigilators. Rule 37 provides for fictitious roll numbers to be allotted to each candidate before the answer books are despatched to the examiners for assessment. Rule 38 provides that the number of answer books to be sent to each examiner shall be fixed by the Commission. Submit