CDS GK Questions 2026

Potassium permanganate, KMnO₄, forms dark purple crystals that contain no water of crystallization; its formula has no attached water molecules.

This statement is wrong because bryophytes, the mosses and liverworts, have no true vascular tissue: they lack xylem to carry water and phloem to carry food.

As rivers come down from the mountains onto the plains, their slope suddenly drops and they can no longer carry their heaviest load.

The focus, or hypocentre, is the point inside the Earth where the rocks first break and energy is released. The point on the surface directly above it is the epicentre, which is usually where shaking is felt first and strongest, so statement 1 is correct.

The India State of Forest Report 2021, published by the Forest Survey of India, Dehradun, put the forest cover of Arunachal Pradesh at about 79 per cent of its geographical area, the highest among the four Himalayan states listed.

A reducing agent is the substance that is itself oxidised while it reduces something else. In hydrazine, N₂H₄, nitrogen has an oxidation number of −2; in nitrogen gas, N₂, it is 0.

All three statements describe composite volcanoes, also called stratovolcanoes. Their lava is cooler and more viscous than basalt, so gas cannot escape easily and pressure builds up until the volcano erupts explosively.

World Humanitarian Day is marked every year on 19 August to honour aid workers who have been killed or injured while helping others, and to draw attention to people affected by crises.

A p-type semiconductor is made by adding a small amount of a trivalent impurity, such as boron, aluminium, gallium or indium, to pure silicon or germanium.

A stack is a landform made by erosion, not by deposition. Waves attack a headland and open cracks into caves; when caves on both sides meet, a sea arch forms, and when the roof of the arch collapses, the seaward part is left standing as an isolated rock pillar called…

Friction acts along the surfaces in contact, opposite to the direction of motion, not along the line joining the centres of two bodies, so it is non-central.

The Panama Canal cuts across the narrow Isthmus of Panama in Central America and joins the Caribbean Sea, an arm of the Atlantic, with the Gulf of Panama on the Pacific.

An angle of incidence of zero means the ray falls along the normal, that is, perpendicular to the surface. By Snell's law, n₁ sin i = n₂ sin r; if i is zero, sin i is zero, so sin r is also zero and the angle of refraction is zero.

Lime water is a clear solution of calcium hydroxide, Ca(OH)₂. When carbon dioxide is passed through it, insoluble calcium carbonate, CaCO₃, forms as a fine white precipitate, which makes the lime water turn milky.

In the early sculpture at sites such as Sanchi, Bharhut and Amaravati, the Buddha was not carved as a man; his presence was suggested through symbols, each tied to an event of his life.

Bronze is made by mixing copper (Cu) with tin (Sn), usually about nine parts copper to one part tin. Adding tin makes the metal harder, stronger and more resistant to corrosion than pure copper, which is why bronze was used for tools, weapons, bells, coins and statues.

Fungi have no chlorophyll, so they cannot make their own food by photosynthesis.

Neap tides come when the Sun and the Moon pull on the Earth at right angles to each other, and that happens at the first and third (last) quarter of the Moon.

Statements 1 and 2 are correct, while statement 3 is wrong. The Satluj rises in the Rakas Tal near Lake Mansarovar in Tibet, at about 4,555 m, and is known there as Langchen Khambab.

The offshore oil terminal at Vadinar, on the Gulf of Kachchh in Gujarat, was built to ease the load on Kandla Port.