20 October 2026 Current Affairs: Headlines, GK & MCQs

Tincture of iodine is a true solution, which is homogeneous, so statement I is wrong, while II and III are right.

Shortughai, a Harappan trading settlement in north-eastern Afghanistan, is the site where traces of irrigation canals have been found. Most Harappan farmers relied on river floods and wells, and no canals have been found in the Indus heartland.

Nitrogen dioxide has an unpaired electron, so two of its molecules join to form dinitrogen tetroxide, N 2 O 4.

Sponges belong to the phylum Porifera, a name that means "pore bearers", because their bodies are full of tiny pores.

A split-ring commutator reverses the coil's connection to the outer circuit every half turn, so the current outside flows in one direction only.

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

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

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

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.

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.

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.

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

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.

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

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

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

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.

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.

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.

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.

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).

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.

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

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.

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

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

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

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.

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.

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

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

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.

Methane and chlorine react in sunlight to give chloromethane and hydrogen chloride, not hydrogen gas. This is a substitution reaction: CH4 + Cl2 → CH3Cl + HCl in the presence of sunlight.

On the expenditure side of India's GDP, private consumption is the largest share, investment (gross fixed capital formation) comes next, then government consumption, and net exports come last.

The Fifteenth Finance Commission gave forest and ecology a weight of 10 per cent in deciding each State's share of the divisible pool of Union taxes.

Buying securities puts money into the economy and raising the cash reserve ratio takes it out, but raising the bank rate reduces money supply instead of increasing it.

Both statements match the Jaina tradition: the place of Mahavira's enlightenment and the meaning of asrava. Mahavira left home at about thirty and spent some twelve years in hard penance.

The round drum below the lions of the Sarnath capital carries an elephant, a bull, a horse and a lion; there is no deer.

Indian tradition credits Shalihotra with the science of horses, and veterinary medicine for horses came to be called Shalihotra Shastra after him.

The Cardamom Hills form the southernmost part of the Western Ghats, lying south of the Palghat Gap along the Kerala–Tamil Nadu border.

Boulders and large pebbles are too heavy to be lifted by the water, so the river rolls, slides and drags them along its bed; this is traction.

Corals grow in clear, shallow, warm sea water with plenty of sunlight; fresh water kills them. Coral reefs are built by tiny animals called polyps, which take calcium carbonate from sea water to make hard skeletons.

Dissolution ends the membership of every member, but Article 94 keeps the Speaker in office until just before the new House first meets.

Chaparral is the shrub vegetation of the Mediterranean climate in California, not of the cold Taiga, so this statement is incorrect.

The Kaveri is an old peninsular river with a mature valley, and the Alaknanda is a young Himalayan river still cutting its valley, but the largest east-flowing peninsular river is the Godavari, not the Krishna.

Only three joint sittings have been held since 1950, and they were on exactly these three bills.

Justice M. P. Thakkar's commission inquired into the assassination of Prime Minister Indira Gandhi in 1984; it had nothing to do with Governors.

All four are among the 22 languages listed in the Eighth Schedule. The Eighth Schedule began with 14 languages in 1950, Urdu among them.

Autecology studies one species, or one individual, in relation to the physical and biological conditions of the place where it lives.