Defence GK Questions 2026

Charnockite is a granitic rock of the Archaean Basement Complex and is found in the Nilgiri and Palni hills of the south.

Bhangar is the older alluvium occupying the higher terraces above the present flood level of the rivers, and its soils often hold calcareous concretions known as kankar.

Lignite, or brown coal, is a low-rank coal formed from vegetation buried relatively recently, and the Neyveli field of Tamil Nadu is a Tertiary deposit, as are the petroleum-bearing rocks of Assam and Gujarat.

Sediment settles in layers at ordinary temperatures, so the remains of organisms buried with it are preserved as the layers are compacted and cemented, which is why sedimentary rocks are also called stratified rocks and why the history of life is read from them.

At the close of the Cretaceous, highly fluid lava welled out of long cracks in the crust in the north-western Deccan and spread as sheet after sheet over Maharashtra and parts of Gujarat and Madhya Pradesh; the flat, step-like arrangement of these flows is what the word trap describes.

Limestone is a sedimentary rock composed mainly of calcium carbonate, and when it is subjected to heat and pressure its grains recrystallise into the dense, even-textured rock called marble.

Named after the Dharwar region of Karnataka, it is the oldest metamorphosed sedimentary system in India and is described as highly metalliferous, yielding iron ore, manganese, gold, copper, lead, zinc and mica; the Champion gneiss of the Kolar gold field belongs to it.

The sandstones, shales and limestones of this Purana system, which stretch across central India into the Son valley, contain the conglomerate beds in which diamonds are found, and the Panna mines of Madhya Pradesh as well as the diamonds once traded from the Kurnool area are associated with them.

From the Upper Carboniferous onwards, thick beds of plant material accumulated in troughs and freshwater basins on the Gondwana landmass and were buried under sandstone and shale, giving the coalfields of the Damodar, Mahanadi, Godavari, Son and Wardha valleys.

In geology a rock is any natural aggregate of one or more minerals that forms part of the earth's crust, whether it is hard like granite or soft like clay, and rocks are classified as igneous, sedimentary or metamorphic according to how they were formed.

Root-knot is caused by microscopic soil roundworms of the genus Meloidogyne, which enter the young root, settle in it and make the surrounding tissue swell into knots or galls; the plant then cannot draw water properly and wilts in the afternoon heat even when the soil is moist.

Phytoplasmas are bacteria without cell walls that live in the food-conducting tissue of the plant, and they are carried from plant to plant by sap-sucking leafhoppers, also called jassids; in little leaf of brinjal the leaves become very small and numerous, the plant bushes out and no fruit is set.

Bordeaux mixture is a suspension made by adding a solution of copper sulphate to one of lime, and it is the oldest fungicide still in regular use; it was devised in the Bordeaux region of France against downy mildew of the grapevine and is sprayed today on fruit trees, potatoes…

The correct answer is B, bunchy top of banana, a virus disease in which the plant is severely stunted and its leaves become short, narrow and crowded in a bunch at the top; it is carried by an aphid and by infected suckers used for planting, so control depends on…

Where this micronutrient is short, the leaf blade of cauliflower fails to expand and the leaf is reduced to a narrow, whip-like strip along the midrib, which gives the disease its name; the curd is small or does not form at all.

In khaira disease the leaves of young rice plants develop rusty brown spots that spread until the crop looks scorched, tillering is poor and growth is stunted; an application of zinc sulphate to the soil or as a foliar spray corrects it, which confirms that the cause is a deficiency…

Citrus canker is caused by a species of Xanthomonas, which enters through wounds, insect punctures and stomata and raises raised corky brown lesions, often with a yellow halo, on leaves, twigs and fruit; it spreads in splashing rain, on tools and on infected nursery plants.

The correct answer is A, Colletotrichum falcatum, a fungus that rots the internal tissue of the cane, turning it red with white patches and giving it a sour smell, and which spreads mainly through infected setts used for planting.

The rusts of wheat, named black, brown and yellow after the colour of the pustules they raise on the stem and leaves, are caused by species of Puccinia, and resistance to them was one of the traits selected in the dwarf wheats of the Green Revolution.

The epidemic of the 1840s destroyed the potato crop of Ireland and brought on the famine, and the study of that outbreak by Anton de Bary established plant pathology as a science.