RRB Group D GK Questions 2026

Cement needs one calcareous material, limestone, for its lime, and one argillaceous material, clay or shale, for its silica, alumina and iron oxide; the mixture is burnt in a rotary kiln at about 1450 degrees Celsius to give clinker, which is then ground with gypsum.

About two or three per cent of gypsum, which is calcium sulphate dihydrate, is ground with the clinker because it slows down the hydration of tricalcium aluminate, the compound that would otherwise set almost the moment water was added and leave no time to place the concrete.

Farmyard manure is the decomposed mixture of cattle dung, urine and bedding litter, and in general it carries only about half a per cent of nitrogen, along with roughly the same order of phosphate and potash.

Nitrogen, phosphorus and potassium are the three primary nutrients, and a fertiliser that carries two or more of them in one chemical compound is called a complex or mixed fertiliser; diammonium phosphate, which supplies both nitrogen and phosphate, and the NPK grades sold by number are the familiar examples.

Superphosphate of lime is made by treating rock phosphate with sulphuric acid, and the nutrient it supplies is phosphorus in the form of available phosphate, not nitrogen; it is therefore a phosphatic fertiliser.

Colostrum is the thick, yellowish first milk a mother produces in the first few days after childbirth.

When a magnet moves inside a coil, the magnetic flux linked with the coil changes, and this change produces an electromotive force and a current.

Cooking soda, also called baking soda, is sodium hydrogen carbonate, also known as sodium bicarbonate. It is a mild base made from one sodium, one hydrogen, one carbon and three oxygen atoms.

Particles of matter mix with one another on their own, and there are forces of attraction between them; both are basic properties taught in Class 9 science.

Black copper(II) oxide reacts with dilute hydrochloric acid to form copper(II) chloride and water, and the solution turns blue-green because of the copper(II) ions.

These ducts and glands do not make sperm; they help sperm mature, store and move them, and add the fluid in which sperm swim.

Marble, chalk and limestone are all made of the same compound, calcium carbonate, with the formula CaCO3. They differ only in how they were formed.

India does not have the largest railway network in the world; the United States has the longest, followed by China and Russia, with India in fourth place.

The eyes of a potato are nodes with buds, and only a stem bears nodes and buds, so they prove that the potato is a modified stem.

He built the Chennakesava temple at Belur in the Hassan district to mark his victories, including the defeat of the Cholas at Talakad, and his reign from about 1108 to 1152 also saw the beginning of the Hoysaleswara temple at Halebidu.

Sarangadeva served at the court of Singhana II, the most powerful Yadava king, and his Sangita Ratnakara is the work from which both the Hindustani and the Carnatic traditions later drew their theory of ragas and talas.

Under this last great Yadava king Marathi flourished as a language of administration and devotion, and the saint Jnaneshwar wrote the Jnaneshwari, also called the Bhavarthadipika, in 1290.

Rudrama Devi was the daughter of Ganapatideva and succeeded him at Warangal, holding the throne for about three decades against rebellions by nobles and attacks from the Yadavas and the Pandyas, and the Venetian traveller Marco Polo wrote with admiration of her government.

The temple at Palampet in Mulugu district of Telangana was built in 1213 by Recherla Rudra, a general of Ganapatideva, and it is named Ramappa after its sculptor, the only temple in India popularly known by the name of its craftsman.

His long reign, from 1076 to 1126, was the cultural high point of the Western Chalukyas, and his court held both Bilhana, who wrote the Vikramankadeva Charita in praise of the king, and Vijnaneshwara, whose Mitakshara became the most widely followed authority of Hindu law in large parts of India.