Railway GK Questions 2026

Thermocol is polystyrene expanded with a blowing agent so that the solid becomes a rigid foam of tiny closed cells.

Buna-S, also called styrene-butadiene rubber, is made by copolymerising 1,3-butadiene with styrene; the S in the name stands for styrene.

Rayon is made by dissolving the cellulose of wood pulp, forcing the solution through fine holes and regenerating the cellulose as a thread.

Polyvinyl chloride has linear chains held to one another only by weak forces, so it softens when heated and hardens when cooled and can be melted and moulded again and again; that reversibility is what makes a plastic thermoplastic, and it is also what allows such plastics to be recycled…

Vulcanisation is the heating of raw rubber with sulphur, which forms short cross-links between the long isoprene chains. Raw rubber is soft, sticky when warm and brittle when cold; the vulcanised product is strong, far more elastic and stable over a wide range of temperature.

Nylon-6,6 is a polyamide formed when hexamethylenediamine condenses with adipic acid, with a molecule of water eliminated at each linkage; the name records that each monomer contributes a chain of six carbon atoms.

Teflon is polytetrafluoroethene, made by the addition polymerisation of tetrafluoroethene. The fluorine atoms shield the carbon chain so completely that the surface is chemically inert, water repellent and almost frictionless, and it holds its properties to high temperature, which is why it coats frying pans and is used for gaskets…

Bakelite is made by condensing phenol with formaldehyde, and on moulding its chains join to one another by strong covalent cross-links into a single rigid network.

Polythene, also written polyethene, is formed by the addition polymerisation of ethene, in which the double bond of each molecule opens and the units join into a long chain with nothing eliminated.

Silk is the protein fibroin, spun by the silkworm, so it is a polymer made by a living organism and is therefore natural, like cellulose, starch, wool and natural rubber.

The special majority of Article 368 has two parts that must be satisfied together: a majority of the total membership of the House, and a majority of not less than two-thirds of the members present and voting.

Article 109 read with Article 117(1) allows a Money Bill to be introduced only in the Lok Sabha, and Article 110(1) permits its introduction only on the recommendation of the President; it is always a Government Bill moved by a minister.

The Rajya Sabha is a permanent House that is never dissolved, so a Bill that originated there and has not yet been passed by the Lok Sabha survives the dissolution of the Lok Sabha and remains alive in the Rajya Sabha.

A Money Bill is introduced in the Lok Sabha only on the recommendation of the President, so the government has already obtained the President's approval of the proposal; Article 111 therefore allows the President only to assent to it or to withhold assent, not to return it.

Once both Houses pass a Bill it is presented to the President, who may declare assent, declare that assent is withheld, which is the absolute veto, or return an ordinary Bill once with a message for reconsideration, which is the suspensive veto; if the Houses pass it again the President…

The two Houses disagreed over its amendments, a joint sitting was summoned in 1961, and the Bill became the Dowry Prohibition Act, 1961.

Article 368 requires each House to pass such a Bill separately by a special majority, and the Constitution provides no joint sitting for it; a Money Bill is also outside the scope of Article 108.

A joint sitting is summoned by the President but presided over by the Speaker of the Lok Sabha; if the Speaker is absent the Deputy Speaker presides, and in the absence of both the Deputy Chairman of the Rajya Sabha takes the chair.

Article 108 allows the President to summon a joint sitting of the two Houses when the other House has rejected the Bill, when the Houses have finally disagreed on the amendments to be made, or when more than six months have passed without the other House passing it.

Under Article 109 a Money Bill passed by the Lok Sabha is transmitted to the Rajya Sabha, which may only make recommendations and must return the Bill within fourteen days.