Defence GK Questions 2026

A light year is a unit of distance, not of time or brightness. One light year is the distance light travels through a vacuum in one Julian year.

Among the four rocky inner planets, Earth is the largest, with a diameter of about 12,742 km. The inner or terrestrial planets are Mercury, Venus, Earth and Mars, all made of rock and metal.

Using Q = mcΔT, the mass works out to 20,000 ÷ (400 × 10) = 5 kg. The heat needed to warm a body is Q = mcΔT, where m is the mass, c the specific heat capacity and ΔT the rise in temperature.

Harishena was the court poet and minister of the Gupta ruler Samudragupta and wrote this praise-poem in his honour. The Prayaga Prashasti, also called the Allahabad Pillar Inscription, is in elegant Sanskrit and is engraved on the same pillar that carries an edict of Ashoka.

A beam seen from the side is visible only because tiny particles send some of its light sideways. Light travelling in a straight line cannot enter our eyes unless something redirects it towards us.

The second industrial revolution, from about 1850 to 1914, was driven by steel, chemicals, electricity and oil. The first industrial revolution began in Britain around 1760 and rested on cotton textiles, coal, iron and the steam engine.

Power is the reciprocal of focal length in metres, and a concave lens has a negative focal length. The power of a lens is P = 1/f, with f in metres, and its unit is the dioptre (D).

The formula T₀ = 2π√(L/g) holds only for small swings; at large amplitudes the period grows.

On a level curve, friction alone supplies the centripetal force, so a cyclist slips when the needed force exceeds the maximum friction.

The New Development Bank was founded by the five BRICS countries, and Canada is not one of them. The founding members are Brazil, Russia, India, China and South Africa.

Copper is less reactive than lead, so it cannot push lead out of its compound. In a displacement reaction, a more reactive metal takes the place of a less reactive metal in its salt solution.

When the jobs on offer need skills, or are in places, that do not match the workers available, people stay jobless even though vacancies exist.

Graphite has free electrons that can move through it, so it conducts electricity; diamond and fullerene do not conduct well.

In a short circuit the live and neutral wires touch, the resistance of the path falls almost to zero, and the current shoots up.

The route runs from the dry west to the wet east coast, so the vegetation changes as rainfall rises. Bikaner lies in the Thar Desert of western Rajasthan, where rainfall is below about 25 cm and only desert plants such as khejri and cactus grow.

A leaf from a sunny day is full of starch made by photosynthesis, and iodine turns starch blue-black. This is the standard school test for starch in a leaf.

A body moving faster than sound outruns its own sound waves, which pile up into a shock wave heard on the ground as a sonic boom.

The Sugamya Bharat Abhiyan is a campaign to make places, transport and information accessible; it is run by the Department of Empowerment of Persons with Disabilities and has no pension component.

Xylem carries water along with the minerals dissolved in it from the roots up to the stem and leaves. Plants have two kinds of conducting tissue.

Olivine is a silicate of magnesium and iron that forms greenish crystals and is common in basalt. Olivine takes its name from its olive-green colour.