NDA GK Questions 2026

Acetic acid boils far above methane, and ethanol gives hydrogen with sodium, while statements 1 and 4 are false. Propyne (CH3–C≡CH) is an alkyne: it has one carbon–carbon triple bond and no double bonds, so statement 1 is wrong.

Gypsum heated at 373 K becomes calcium sulphate hemihydrate, CaSO4 · ½H2O, which is plaster of Paris, not CaSO4 · H2O as the statement says.

Myxomatosis passes from rabbit to rabbit through biting insects and contact, so it spreads fastest where rabbits are crowded together.

Making a genetically modified organism needs all three steps: find the useful DNA, put it into the host, and make sure the host keeps it and passes it on.

The ozone hole, a sharp seasonal thinning of stratospheric ozone, forms every southern spring over Antarctica. During the long polar winter a strong circular wind, the polar vortex, isolates the air over Antarctica, and temperatures fall low enough to form polar stratospheric clouds.

Eutrophication is the enrichment of a water body with nutrients, so statement 2 is correct, while statement 1 describes the opposite condition.

The zygote is diploid (2N) and the primary endosperm nucleus is triploid (3N). Double fertilisation is a feature of flowering plants.

The reaction happens because iron is more reactive than copper and pushes it out of its salt, so statement C is false.

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.