Railway GK Questions 2026

In crystallisation a hot saturated solution is allowed to cool slowly, and as it cools only the required substance comes out of solution in the regular form of crystals while the impurities, present in smaller amounts, stay dissolved in the liquid that is left behind, which is called the mother…

When salt dissolves in water it breaks up into separate ions, which are far smaller than the wavelength of visible light, so they cannot scatter a beam sideways and the path of light through the liquid stays invisible.

Chromatography separates substances that are dissolved in the same solvent and present in very small quantities, by letting the solution creep along a strip of filter paper.

Ammonium chloride passes directly from the solid to the vapour state on heating, without melting, while common salt does not.

Brass is made by melting copper with zinc, and the resulting homogeneous mixture is harder than copper, easier to cast and machine and gives the familiar yellow colour used for utensils, fittings and musical instruments.

When two miscible liquids boil at temperatures far apart, ordinary distillation is enough, because the more volatile liquid boils off almost completely before the other begins.

Kerosene and water do not mix, so on standing they form two distinct layers with the lighter kerosene above the denser water.

Milk is an emulsion in which tiny globules of fat are dispersed through water, and those globules fall within the colloidal size range, so milk looks uniform to the eye, does not separate on standing, passes through filter paper and shows the Tyndall effect.

The particles of a colloid are between one and one thousand nanometres across, which is large enough to scatter a beam of light sideways and make the path of the beam visible.

Common salt is sodium chloride, in which sodium and chlorine are chemically combined in a fixed ratio by mass, and the result has properties quite unlike either element, since sodium reacts violently with water and chlorine is a poisonous gas while their compound is eaten daily.

The world governing body for chess was established on 20 July 1924 in Paris, and the anniversary is kept as International Chess Day, with the United Nations later recognising it as an international day in acknowledgement of the reach of the game and of its Indian ancestor, chaturanga.

World Music Day grew out of the Fete de la Musique begun in France, on which musicians of every kind play free in streets and public places.

UNESCO adopted World Poetry Day in 1999 to support the reading, writing, publishing and teaching of poetry and to give a hearing to small publishers and to poetry in endangered languages.

UNESCO declared this day to promote the use and preservation of mother tongues, and the date commemorates the Bengali language movement of 1952, when students in Dhaka were killed while demanding recognition for Bengali in what was then East Pakistan.

That decision, taken on 14 September 1949, was later written into Article 343 of the Constitution, and the anniversary has been observed within India as Hindi Diwas.

A congress convened by Pierre de Coubertin at the Sorbonne in Paris established the International Olympic Committee on 23 June 1894, and national Olympic committees mark the anniversary with runs and open sporting events.

Dhyan Chand was born on 29 August 1905 and was part of the Indian hockey teams that won the Olympic gold medal in 1928, 1932 and 1936; he is regarded as the finest hockey player the country has produced, and the national sports awards are conferred on his birthday each…

The day was proposed by the International Council on Monuments and Sites and approved by UNESCO in 1983, and it is used to draw public attention to the conservation of historic buildings, archaeological sites and cultural landscapes, including the sites on the World Heritage List.

International Museum Day was declared by the International Council of Museums, and on it museums across the world open to the public around a common annual theme meant to show the part museums play in education and in society.

Noverre was the French dancer and choreographer who argued that ballet should tell a story through expressive movement rather than remain a display of steps, and the International Theatre Institute chose his birthday, 29 April, for International Dance Day.