Defence GK Questions 2026

The Tehri dam stands in the Tehri Garhwal district of Uttarakhand, just below the point where the Bhilangana joins the Bhagirathi, and it is the tallest dam in India; it supplies power, drinking water and irrigation, and its construction submerged the old town of Tehri.

Chilika lies along the coast of Odisha, separated from the Bay of Bengal by a long sand bar, and its mixture of fresh and sea water supports one of the largest wintering grounds for migratory birds in the subcontinent as well as a population of Irrawaddy dolphins.

It lies in the Kashmir valley, is fed by the Jhelum, and is the largest freshwater lake in India; it acts as a natural flood absorber for the valley and is a designated wetland of international importance.

Formed by the Varahi river in the Shivamogga district of Karnataka, it is counted as the highest waterfall in India, falling in a long series of steps through rocky terrain; because it lies within the catchment of the Mani dam, its full flow is seen mainly in the monsoon.

Jog Falls is formed by the Sharavathi river where it drops off the edge of the Western Ghats in the Shivamogga district of Karnataka, and it falls in four separate streams traditionally named Raja, Rani, Rocket and Roarer.

The Kaleshwaram project lifts water from the Godavari near the confluence of the Godavari and the Pranahita and carries it through a chain of barrages, pump houses, tunnels and canals to the drier districts of Telangana; it is described as a multi-stage lift irrigation scheme rather than a single storage…

The Maithon dam is built across the Barakar, a tributary of the Damodar, in Jharkhand, and is one of the reservoirs of the Damodar Valley Corporation, so it has nothing to do with the Kaveri.

It is the centrepiece of the Pancheshwar Multipurpose Project, planned on the Mahakali river, which forms part of the boundary between India and Nepal, and it is to be built and operated jointly by the two countries under the Mahakali Treaty for power, irrigation and flood control.

Graphite is an allotrope of carbon in which each atom is bonded to three others, leaving one electron per atom free to move through the layers, so it conducts electricity although it is a non-metal; this is why graphite is used for electrodes and in dry cells.

An amphoteric oxide reacts with both acids and bases to form salts, and aluminium oxide does exactly that, behaving as a base towards hydrochloric acid and as an acid towards sodium hydroxide; zinc oxide is the other amphoteric oxide asked in examinations.

In galvanisation iron or steel is given a coating of zinc, usually by dipping it in the molten metal, and the coating protects the iron in two ways: it keeps out air and moisture, and because zinc is more reactive than iron it corrodes in place of the iron even…

Galena is lead sulphide, the principal ore from which lead is obtained; being a sulphide it is concentrated by froth flotation and then roasted in air to the oxide before reduction.

Silver has the highest electrical conductivity of all metals and also the highest thermal conductivity, but it is costly and tarnishes, so it is used only in specialised contacts and instruments.

Aqua regia is three parts concentrated hydrochloric acid to one part concentrated nitric acid, and the name means royal water, given because the mixture attacks the noble metals gold and platinum, which neither acid can dissolve on its own.

Mercury is the only metal that is liquid at ordinary room temperature, which is why it was long used in thermometers and barometers; it is also the metal that forms amalgams, alloys in which mercury is one component.

Brass takes the workability of copper and the hardness of zinc, resists corrosion and is easy to cast, which is why it is used for utensils, locks, taps, fittings and wind instruments.

Ductility is the property of being drawn into a wire, and gold is the most ductile metal known; it is also the most malleable, so a very small quantity can be beaten into an extremely thin sheet or drawn into a very long wire.

Silver is an element, a pure metal with its own place in the periodic table, so it cannot be an alloy; an alloy is a homogeneous mixture of two or more metals, or of a metal with a non-metal such as carbon.

Calamine is zinc carbonate, and since it is a carbonate ore it is converted to the oxide by calcination, that is by heating in the absence of air, before being reduced to the metal.

The female egg cell, or ovum, is the largest cell in the human body. It measures about 100 to 130 micrometres across, roughly the thickness of a hair, and is the only human cell that can just be seen without a microscope.