M.JEYAPAUL,J. - (1.) On 24.6.2016, the following order was passed by me: " It is the contention of the writ petitioner that the model answer key for Question No. 43 finalized by the expert is wrong, whereas the answer given by the petitioner to Question No. 43 is correct. It is also the contention of the petitioner that Question No. 50 had wrongly been formulated as it was found that two options out of four given in that question were found to be correct. It is also contended that the petitioner submitted a representation on 04.05.2016 but the same was not responded by the respondents. To redress the above grievance articulated by the petitioner in the present writ petition, the respondents are directed to send these two questions alongwith the documents/papers annexed with the present civil misc. application and the model answer key to an expert on the relevant subject serving at Indian Institute to Technology/National Institute of Technology for his/her expert opinion and the opinion so given be produced in the Court in a sealed cover on the date fixed."
(2.) Counsel appearing on either side are present today. Their submissions were heard.
(3.) As directed, the Expert's opinion was produced by the counsel for the respondents in a sealed cover. The sealed cover was opened by me. The expert opinion given by the Expert reads as follows: " Q. 50 BOD - What is more appropriate - Biochemical oxygen demand or biological oxygen demand ? The Class XI NCERT book states that BOD is an acronym for biochemical oxygen demand while in another one of its handbooks it defines BOD as biological oxygen demand. Neither publication mentions that both are appropriate. After considering various texts on environmental chemistry (Environmental Biotechnology - Daniel A. Vallero, Elsevier, 2010 ISBN 978 -0 -12 -375089 -1; Environmental Laboratory exercise for instrumental analysis and environmental chemistry -Frank M. Dunnivant, Wiley -Interscience, 2004, ISBN 0 -471 -48856 -9) - Biochemical oxygen demand is the correct and a more appropriate answer. This refers to the amount of oxygen needed by aerobic organisms to metabolize organic compounds in water. Biological oxygen demand is a misleading interpretation as it also includes aerobic and anaerobic requirements. Biochemical oxygen demand refers specifically to the demand of biological systems that are aerobic in nature. Thus the interpretation of the NCERT book on page 401 of class XI is correct. Thus the option, biochemical oxygen demand is most appropriate answer and the biological oxygen demand is misleading. To a question what gas do we breathe? Oxygen, carbon dioxide and air are all appropriate answers but we all know that oxygen is what we should breathe. This is a similar question. Q. 43 Identify the incorrect statement regarding heavy water: (1) It reacts with Al4C3 to produce CD4 and Al (OD)3. (2) It is used as a coolant in nuclear reactors. (3) It reacts with CaC2 to produce C2D2 and Ca (OD)2. (4) It reacts with SO3 to form deuterated sulphuric acid (D2SO4). Heavy Water (D2O) shows comparable physical and chemical properties to ordinary water. It is its nuclear properties (slowing down power and low absorption cross sections for neutrons) which differ significantly from normal water that makes it an extremely efficient material to be used as moderator in a nuclear reactor. The question is addressed to Class XII students to bring their attention to the most common nuclear property of "heavy water". Out of the three options, three refer to chemical properties and one nuclear property. The statements 1, 3 and 4 are correct. The choice of the second statement was intentional to highlight its nuclear property (NCERT textbook class 12 in physics; section 13.7 discusses the whole concept of reactors and coolant). A comparison of light water versus heavy water Coolants: A coolant carries heat from the core to the turbine. Water (H2O) has a high specific heat, inexpensive but does absorb some neutrons (absorption = 0.332 barns). Heavy water (D2O) also has high specific heat, very expensive and does not absorb many neutrons (absorption=5.2 x 10 -4 barns). Moderators: A moderator greatly slows down neutrons from their high kinetic energy of 1 -10 MeV to really slow neutrons thermal neutrons with a kinetic energy of about 0.025 eV, the typical kinetic energy of molecules in a gas at room temperature. Typically, moderators contain small nuclei. The neutron kinetic energy is shared in collisions of the fast neutrons with nuclei of comparable size. H2O is an excellent moderator because of the hydrogen nuclei (protons) in the water." ;