UPSC GK Questions 2026

The number after PM gives the upper size limit of the particles in micrometres. Particulate matter is classed by aerodynamic diameter: PM10 is 10 micrometres or less, PM2.5 is 2.5 micrometres or less, and PM1 is 1 micrometre or less, about one-seventieth of a human hair's width.

A liquid boils when its vapour pressure equals the pressure above it, so less outside pressure means boiling starts at a lower temperature.

All three subjects sit in the list named against them in the Seventh Schedule. The Seventh Schedule, read with Article 246, divides law-making powers into three lists.

Magnesium burns in air with a dazzling white flame, which is why it goes into fireworks, sparklers and flares. When magnesium ribbon is heated it reacts with oxygen to form white magnesium oxide (2Mg + O2 → 2MgO), giving out intense heat and brilliant white light, including ultraviolet.

A short-sighted (myopic) person sees near things clearly but distant things blurred, and a concave lens corrects it.

A compound microscope uses two convex lenses, and its magnification depends on the tube length. The objective is a convex lens of very short focal length that forms a real, enlarged image of the specimen.

The third law does not make one force the cause and the other the effect; action and reaction arise together, at the same instant.

A real, inverted image of the same size forms only when the object sits at twice the focal length of a convex lens, so 2f = 10 cm and f = 5 cm.

Sunlight reaching a glasshouse is mostly visible light and short-wavelength (near) infrared, which glass transmits easily. The plants and soil inside absorb it, warm up and re-radiate the energy as long-wavelength infrared, because cooler bodies emit at longer wavelengths.

Plantations do lie mostly in the humid tropics, but the soils there are generally poor, not highly fertile. Plantation farming grows a single cash crop such as tea, coffee, rubber, sugarcane, cocoa, banana or oil palm on large estates with heavy capital and hired labour.

Light inside the fibre strikes the boundary at more than the critical angle, so it is reflected back again and again instead of escaping.

A short notice question is an urgent oral question taken up only with the Minister's consent, and it is answered after Question Hour, not during it.

A speed radar measures how much the frequency of its reflected wave changes, and that change depends on the speed of the vehicle.

Both kinds of radiation carry energy that food absorbs as heat, and both are used in everyday kitchens. Infrared radiation is the heat radiation given out by hot bodies: a grill, a toaster, an oven element or glowing coals cook the surface of food mainly by infrared rays.

In January the northern oceans are warmer than the frozen continents, so isotherms bend north over the sea and south over the land; the Gulf Stream and North Atlantic Drift are warm currents, not cold ones.

Equality means that no person or group enjoys special rights denied to others, so it implies the absence of privileges.

The Global Competitiveness Report is the World Economic Forum's assessment of how well countries' institutions, policies and markets support productivity and growth.

Indian bond yields respond to the RBI's policy, to domestic inflation and short-term rates, and also to the US Federal Reserve through global capital flows.

The Common Framework for Debt Treatments was agreed by the G20 and the Paris Club in November 2020 to help low-income countries with unsustainable debt.

Mahua and teak shed their leaves in the dry season, while the jackfruit tree is evergreen.