CTET GK Questions 2026

In a soda-acid extinguisher a solution of sodium hydrogen carbonate is kept in the body of the cylinder and sulphuric acid in a sealed glass phial.

When milk is set into curd, the bacteria Lactobacillus convert the milk sugar lactose into lactic acid, and it is this acid that gives curd its sour taste and makes the milk protein clot.

Aqua regia is a freshly prepared mixture of three parts concentrated hydrochloric acid to one part concentrated nitric acid. Neither acid alone attacks gold, but together they do, because the nitric acid oxidises the metal while the chloride ions hold the gold in solution as a complex.

Gypsum is calcium sulphate dihydrate, and heating it carefully to about 373 kelvin drives off three quarters of its water to leave calcium sulphate hemihydrate, which is Plaster of Paris.

It is a mild, non-corrosive base. In baking it releases carbon dioxide on heating and makes the dough rise, in medicine it neutralises excess acid in the stomach, and in a soda-acid fire extinguisher it reacts with sulphuric acid to produce the carbon dioxide that smothers the flame.

Boric acid dissolves in water to give a true solution, in which the dispersed particles are individual molecules small enough to pass through a filter paper and even a parchment membrane, and the mixture shows no Tyndall effect.

Rayon is made by dissolving the cellulose of wood pulp in a chemical and forcing the solution through fine holes to form filaments.

A dilute solution of iodine gives a deep blue-black colour with starch, which is a polysaccharide and therefore a carbohydrate.

In graphite each carbon atom is joined to only three other carbon atoms in flat hexagonal layers, so the fourth valence electron of every atom is not used in bonding and can move freely along the layer.

A block lying quietly on a table is in equilibrium, so the forces on it must add up to zero, but that does not mean there are no forces at all.

Mehrgarh, on the Bolan river in the Kachi plain of Baluchistan, is the earliest known farming village in the Indian subcontinent, occupied from about 7000 BCE.

A brand is the name, term, sign, symbol or design a seller gives a product so that buyers can tell it apart from everything else on the shelf.

When the British left in 1947, India had, besides the provinces under direct British rule, about 565 princely states whose rulers had accepted British paramountcy.

Plant tissues are first divided into meristematic tissue, whose cells keep dividing, and permanent tissue, whose cells have stopped dividing and have taken a fixed shape and job.

The middle ear holds three tiny bones, the smallest in the human body, called the malleus, the incus and the stapes, which in everyday English are the hammer, the anvil and the stirrup.

Sound is a mechanical wave: it travels only when the particles of a medium push against their neighbours, so the closer and more tightly bound those particles are, the faster the disturbance is passed on.

A unisexual flower carries only one kind of reproductive organ, either stamens or a pistil, while a bisexual flower carries both.

In the binary system every place stands for a power of two, and 257 is 256 plus 1, that is two raised to the eighth plus two raised to the zero.

James Mill did publish A History of British India in 1817 in three volumes, so the first statement is correct.

A primary source is one produced in the very period being studied, and the Allahabad Pillar Inscription, the prashasti composed by the court poet Harisena in praise of Samudragupta, was carved in the fourth century CE, inside the ancient period itself.