Defence GK Questions 2026

Article 370 was one of the articles of Part XXI of the Constitution, which is titled Temporary, Transitional and Special Provisions, and its marginal heading read Temporary provisions with respect to the State of Jammu and Kashmir.

A water molecule has two hydrogen atoms of atomic mass one and one oxygen atom of atomic mass sixteen, so the masses are two and sixteen, which is a ratio of one to eight; this fixed ratio in every sample of water, whatever its source, is the classic illustration of…

Cholera is caused by the bacterium Vibrio cholerae and spreads through water and food contaminated with faecal matter, which is why it breaks out after floods and wherever sewage mixes with the water supply; typhoid, hepatitis A, dysentery and polio spread the same way.

Soap is the sodium or potassium salt of a long chain fatty acid.

A moderator slows down the fast neutrons released by fission so that they can cause further fission, and heavy water is the best of them because it slows neutrons well while absorbing very few; in Indian pressurised heavy water reactors it also serves as the coolant that carries heat away…

In reverse osmosis the water is pushed through a semi-permeable membrane at a pressure greater than its osmotic pressure, so the flow runs opposite to natural osmosis; the membrane lets water molecules through and holds back dissolved salts, heavy metals and most microbes, which is why reverse osmosis is also…

Bleaching powder is prepared by passing chlorine over dry slaked lime and is written as calcium oxychloride; in water it releases chlorine, which kills bacteria and other pathogens, and that is why it is used both for disinfecting water supplies and for bleaching cloth and paper.

Alum, that is aluminium sulphate or potash alum, is a coagulant: in water it forms a gelatinous hydroxide that gathers the fine clay and colloidal particles into heavier flocs, which then settle in the sedimentation tank and are removed, leaving clear water for filtration.

Water contracts as it is cooled to four degrees, is densest at that temperature, and then expands again as it cools further to zero, which is called the anomalous expansion of water.

These bicarbonates are formed when water containing dissolved carbon dioxide passes over limestone, and they are unstable; on boiling they lose carbon dioxide and settle as insoluble carbonates, which is why this kind of hardness is called temporary and can be removed by boiling alone, or by the Clark method…

Heavy water is D2O, in which both hydrogen atoms are deuterium, the isotope whose nucleus has one proton and one neutron, so its molecular mass is twenty instead of eighteen.

In an ion exchange plant the water passes through a cation resin, which takes up the calcium and magnesium ions, and then through an anion resin, which takes up the sulphate, chloride and bicarbonate ions; because the hardness-causing ions are actually taken out of the water, the hardness can be…

A bench of five judges decided it in 2022 and upheld the Constitution (One Hundred and Third Amendment) Act, 2019, which provides up to ten per cent reservation for the economically weaker sections, by a majority of three to two.

It reserves seats in the House of the People, that is the Lok Sabha, for the Scheduled Castes and the Scheduled Tribes, the number being in proportion to their population; there is no reservation of seats for the Other Backward Classes in Parliament.

It empowers the President to appoint a commission to investigate the conditions of socially and educationally backward classes, the difficulties they face and the steps that should be taken to remove them, and both the Kalelkar Commission of 1953 and the Mandal Commission of 1979 were appointed under it.

The first Backward Classes Commission was appointed in 1953 under Article 340 with Kaka Saheb Kalelkar as its chairman, and it submitted its report in 1955; the report was not acted upon because its criteria for identifying backwardness were considered vague.

The Constitution (One Hundred and Second Amendment) Act, 2018 inserted Article 338B, which makes the National Commission for Backward Classes a constitutional body with the duty to investigate and monitor the safeguards provided to the socially and educationally backward classes; the same amendment added Article 342A for the central list…

It amended Article 16(4A) so that a government servant of the Scheduled Castes or Scheduled Tribes promoted under the reservation also keeps the seniority of the promoted post, which is called consequential seniority, and the change was given effect from 1995.

It was passed after the Supreme Court in State of Madras v. Champakam Dorairajan struck down a communal order reserving seats in colleges, holding that it offended Article 15(1); Parliament answered by adding clause (4) to Article 15, which permits special provision for the advancement of socially and educationally backward…

The nine-judge bench in Indra Sawhney upheld the twenty-seven per cent quota for the Other Backward Classes but held that the socially advanced members of those classes, described as the creamy layer, must be excluded so that the benefit reaches the genuinely backward; the same judgment laid down the fifty…