NDA GK Questions 2026

Both statements are true, and the second explains the first: infrared waves are called heat waves because water molecules, present in most materials, absorb them readily and heat up.

Heat is energy in transit: it flows from a hotter body to a colder one only because their temperatures differ, and stops when they reach the same temperature.

The SI unit of inductance is the henry, symbol H, named after the American scientist Joseph Henry. Inductance measures how strongly a coil opposes a change in the current through it by producing an induced emf.

Plaster of Paris is calcium sulphate hemihydrate, CaSO₄·½H₂O, so one molecule of water is shared by two formula units of calcium sulphate, written (CaSO₄)₂·H₂O. It is made by heating gypsum, CaSO₄·2H₂O, to about 373 K (100 °C), when gypsum loses one and a half molecules of water per formula unit.

In the order visible light → ultraviolet → X-rays, the wavelength falls and the photon energy rises, so statements 1 and 2 are true and 3 is false.

In 1905 Einstein explained the photoelectric effect by treating light as made of packets of energy, later called photons, and he received the 1921 Nobel Prize in Physics for this work.

Light inside an optical fibre strikes the wall at more than the critical angle, is totally reflected back inside, and repeats this again and again along the fibre.

Fly ash is the fine powdery residue left after coal is burnt in thermal power stations; it is a mixture of oxides, not a pure form of carbon.

Urea, CO(NH₂)₂, contains carbon, oxygen, nitrogen and hydrogen; it has no phosphorus at all and is a nitrogenous fertilizer. Urea carries about 46% nitrogen, the highest of the common solid fertilizers, which is why it is the most widely used fertilizer in India.

X-rays are not used in radar; radar works with microwaves, which have wavelengths of a few centimetres. X-rays lie between ultraviolet rays and gamma rays in the electromagnetic spectrum, with wavelengths from about 10 nm down to 0.01 nm, so about 1 Å (0.1 nm) is typical.

It is an inorganic salt made of the ammonium ion and the cyanate ion, with no carbon–hydrogen bonds. Ammonium cyanate is famous in chemistry because in 1828 Friedrich Wöhler heated it and obtained urea.

Pairs I, II and IV describe the electron transfer correctly; pair III calls bromine a reductant when it is the oxidant.

Boiling an oil or fat with an alkali splits it into glycerol and the salts of its fatty acids; with potassium hydroxide those salts are potassium salts.

Manish Narwal took the silver in the men’s event and Shrishti Arora the bronze in the women’s event, so the distance, the weapon and the class code are identical and only the section and the colour of the medal differ.

Shrishti Arora secured the bronze in the Women’s 10m Air Pistol SH1 event on 20 October 2026 while competing at the Games for the first time, and the Prime Minister described the medal as a wonderful beginning, saying he was confident she would continue to make the nation proud.

Manish Narwal finished second in that event at the Asian Para Games 2026 on 20 October 2026, and the Prime Minister called it an impressive performance, adding that the shooter kept setting himself apart through his focus and his commitment.

Pairs I and III are correct; the IL-76 is a heavy transport aircraft, not a supersonic fighter.

The magnetic field has flipped many times and life changed the early air, but the young Earth had almost no free oxygen.

Pulicat Lake lies in two states, but the Himalayas and the Western Ghats each spread over more than five states.

Ice caps and glaciers hold more water than groundwater, while rivers and lakes hold far less than groundwater. About 97 per cent of the Earth's water is salty ocean water, and only about 2.5 to 3 per cent is fresh.