NDA GK Questions 2026

The magnetic field inside a long solenoid is B = μ₀nI, where n is the number of turns per unit length and I is the current, so the field depends on these two and not on the diameter.

Electromagnetic waves need no medium, so they travel through vacuum, and they consist of electric and magnetic fields that oscillate at right angles to each other and to the direction of travel.

In many single-celled organisms such as Amoeba and Paramecium, a special contractile vacuole collects excess water and some wastes from the cytoplasm and pumps them out of the cell.

A pollen grain lands on the stigma, grows a pollen tube that travels down through the style, and enters the ovary to reach an ovule, where fertilisation takes place.

A generator, whether AC or DC, produces electricity because a coil rotating in a magnetic field has a changing magnetic flux through it, and Faraday's laws say that a changing flux induces an electromotive force.

Autotrophs take carbon dioxide from their surroundings and build their own organic food from it, so CO₂ is their main source of carbon.

Soap in water forms a lyotropic liquid crystal, a phase whose ordered structure appears because of the amount of solvent mixed in, not because of temperature alone.

Maize is a crop of the Americas, and it reached India in the sixteenth and seventeenth centuries via Africa and Spain; by the seventeenth century it had become one of the major crops of western India.

In India's land-use classification, land that is left uncultivated for more than five agricultural years is recorded as culturable waste land, even though it could be brought back under cultivation with reclamation.

There is no compound with the formula 4CaO·SiO₂ in Portland cement; the four main compounds of cement clinker are dicalcium silicate, tricalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite.

Rainfed Area Development is meant for farms that depend on rain, not on canals, so improving canal irrigation is not one of its strategies.

A typical flower has four whorls arranged on the thalamus: sepals on the outside, then petals, then stamens, and carpels at the centre.

A convex mirror always forms an erect, diminished image, so it shows a much wider area of the road behind than a flat mirror of the same size, which is why it is used as a rear-view or side-view mirror.

Hajipur in Bihar is the headquarters of the East Central Railway zone, which began working in 2002. Indian Railways is divided into zones, each with its own headquarters and divisions.

Decomposition breaks rocks down at the surface and is a process of weathering, whereas metamorphism changes rocks deep inside the crust through heat, pressure and chemically active solutions.

Wire B has half the resistance of wire A, and at the same voltage power is V²/R, so B dissipates twice the power: P₁ = 2P, which means P = P₁/2.

The Sun's surface is about 6,000 °C, so most of its energy reaches the Earth as short-wave radiation: visible light and near (short wavelength) infrared, with a small share of ultraviolet.

The radicle is the embryonic root, and it is the first part to come out of a germinating seed, growing downward to form the primary root.

Pressure is force divided by the area in contact: the weight is 2 kg × 10 m/s² = 20 N and the face touching the table is 0.30 m × 0.10 m = 0.03 m², so the pressure is 20 ÷ 0.03 ≈ 666.6 N/m².

Electric charge equals current multiplied by time, Q = I × t, with time in seconds: 0.6 A × 600 s = 360 coulombs.