CDS GK Questions 2026

These four elements make up the complex tissue that carries water and minerals upward from the roots. Tracheids and vessels are long, dead, thick-walled tubes through which water moves; xylem parenchyma is the only living part and stores food; xylem fibres give support.

The major languages of India belong to four language families: Indo-European (Indo-Aryan), Dravidian, Austric (Austro-Asiatic) and Sino-Tibetan. The Indo-Aryan branch of the Indo-European family is the largest, spoken by about three-quarters of Indians and including Hindi, Bengali, Marathi, Gujarati, Punjabi and Odia.

In the Raman effect, a small part of the light scattered by molecules comes out with a changed frequency. C.V.

An oxbow lake forms when a river erodes the outer banks of a meander and deposits silt that seals off the loop, so it needs both erosion and deposition.

This is a hydrolysis reaction in which no element changes its oxidation number, so nothing is oxidised or reduced. A redox reaction is one in which one substance loses electrons (its oxidation number rises) and another gains them (its oxidation number falls).

Ramesh is short-sighted with a far point of 2 m, so he needs a concave lens of focal length −2 m, whose power is 1/(−2) = −0.5 dioptre.

Sound in liquids and gases travels as a longitudinal wave, not a transverse one. In a longitudinal wave the particles of the medium vibrate back and forth along the direction in which the wave moves, forming compressions and rarefactions.

Light from an object at the centre of curvature strikes a concave mirror along its radius, so it returns along the same path and forms the image at the same point.

A substance that loses hydrogen is oxidised, not reduced, so statement A is the incorrect one. In the classical definitions, oxidation means the gain of oxygen or the loss of hydrogen, and reduction means the loss of oxygen or the gain of hydrogen.

Ibn Battuta came in the 14th century, Nikitin in the 15th, Monserrate in the 16th and Peter Mundy in the 17th.

Nettle stings contain methanoic (formic) acid, so statement I is right, while statements II and III name the wrong compounds.

Renin, released by the kidney, converts angiotensinogen made by the liver into angiotensin I, which is then changed into angiotensin II.

At a fixed speed v, centripetal acceleration equals v²/r, so a larger radius gives a smaller acceleration. An object moving in a circle at constant speed is still accelerating, because its direction keeps changing.

In a reflex arc the message runs from the sense organ to the spinal cord and straight back to a muscle or gland.

A nuclear reactor splits heavy nuclei such as uranium-235 in a chain reaction that is kept under control, releasing heat at a steady rate.

Mitochondria have their own DNA and their own ribosomes, so they can make some of the proteins they need. Mitochondria are the "powerhouses of the cell", where food is broken down in aerobic respiration to release energy stored as ATP.

Of the four states listed, Punjab had the smallest population in the 2011 Census, about 2.77 crore people. The 2011 Census, the fifteenth census of India, counted about 121 crore people in all.

Reverberation is the lingering of sound in a closed space caused by many reflections from the walls, ceiling and floor.

John Kay, an English inventor, patented the flying shuttle in 1733, one of the first machines of the Industrial Revolution.

The element with atomic number 35 is bromine, whose 35 electrons are arranged as 2, 8, 18, 7, leaving seven in the outermost shell.