NDA GK Questions 2026

Brihadratha was the last ruler of the Mauryan dynasty. About 185 BCE his own commander-in-chief Pushyamitra Sunga killed him, according to tradition at a review of the army, and took the throne at Pataliputra.

The panel showing the submission of the mad elephant Nalagiri, sent by Devadatta to kill the Buddha and calmed by him in the street of Rajagriha, is among the best known carvings of the Amaravati stupa on the lower Krishna in Andhra Pradesh.

The Gathasaptasati, also written as Gatha Saptasati, is an anthology of seven hundred short verses compiled by the Satavahana king Hala.

Ashvaghosha was a Buddhist monk and Sanskrit poet at the court of the Kushana ruler Kanishka I. He wrote the Buddhacharita, a life of the Buddha in Sanskrit verse, and the Saundarananda, and he acted as deputy to Vasumitra at the Fourth Buddhist Council held in Kashmir.

Nahapana belonged to the Kshaharata family of the Shakas, the Western Kshatrapas who ruled in western India, and not to the Kushanas at all.

The main Kushana capital was Purushapura, the modern Peshawar, which Kanishka I developed as his seat of power. As the empire spread into the Ganga-Yamuna plain, Mathura on the Yamuna became its second capital and the southern headquarters of the family.

White light is a mixture of colours, and the refractive index of the glass of a prism is slightly different for each of them, being greatest for violet and least for red.

In myopia the eyeball is too long or the lens of the eye too strongly converging, so rays from a distant object meet in front of the retina and the person cannot see far objects clearly.

An optical fibre is a thin thread of glass or plastic with a core of higher refractive index surrounded by a cladding of lower refractive index.

On a hot day the air touching the road is heated and becomes rarer than the cooler air above it.

The power of a lens is the reciprocal of its focal length expressed in metres, that is P equals 1 divided by f. Fifty centimetres is 0.5 metre, and the reciprocal of 0.5 is 2, so the power is two dioptres.

A convex mirror curves outward and spreads the light that falls on it, so it always forms a virtual, erect and diminished image, whatever the distance of the object.

Rays reflected from a plane mirror diverge and only appear to come from a point behind the mirror, so the image cannot be caught on a screen and is virtual.

Newton passed a narrow beam of sunlight through a glass prism in a darkened room and obtained a band of seven colours on the wall, which he named the spectrum.

By the sign convention the focal length of a concave lens is negative, so f is minus 15 centimetres, and the object distance measured against the direction of the incident light is minus 30 centimetres.

A denser medium has a higher refractive index, and the refractive index is the speed of light in vacuum divided by its speed in the medium, so light must travel more slowly inside it.

Distillation separates a liquid from a solution or from another liquid by boiling it and condensing the vapour, so it is used when the components differ in boiling point, as in getting pure water from salt water or separating acetone from water.

Among the allotropes of carbon, graphite has the lowest standard enthalpy of formation, which is taken as zero, so it is the reference state and the most stable form under ordinary conditions of temperature and pressure.

A conservative force is one whose work depends only on the starting and the finishing point, not on the path taken, and whose work around any closed path is zero.

Vyommitra is a half-humanoid robot built by the Indian Space Research Organisation and shown to the public in January 2020.