SSC GK Questions 2026

Limestone decomposes in the furnace to calcium oxide, a basic flux, which combines with the acidic silica gangue of the ore to form calcium silicate, a fusible slag that floats on the molten iron and is drawn off separately.

In the Mond process impure nickel is heated in a stream of carbon monoxide at a moderate temperature, forming the volatile compound nickel tetracarbonyl; the vapour is led away from the solid impurities and heated more strongly, whereupon it decomposes and deposits very pure nickel.

Galvanisation is the coating of iron or steel with zinc, usually by dipping it in molten zinc.

Pure alumina melts at a very high temperature, so in the Hall and Heroult process it is dissolved in molten cryolite, sodium hexafluoroaluminate, usually with some fluorspar, which lowers the working temperature of the bath and makes the melt a far better conductor of electricity.

German silver is an alloy of copper, zinc and nickel, and its name comes from its white silvery appearance, not from its composition, since it contains no silver at all; it is used for tableware, ornaments and electrical contacts.

Brass is made by alloying copper with zinc, which gives a metal harder than copper, easier to cast and machine, and resistant to ordinary corrosion, so it is used for utensils, taps and fittings and the bodies of musical instruments.

Zone refining rests on the fact that impurities are more soluble in a molten metal than in the same metal when solid.

Calcination is the heating of an ore in the absence or a limited supply of air and below its melting point, so that water of hydration and carbon dioxide are driven off; it is therefore the step used for carbonate ores such as calamine and for hydrated ores such as…

In froth flotation the powdered ore is agitated with water, a frothing agent such as pine oil and a collector.

Galena is lead sulphide, with the formula PbS, and is the principal ore from which lead is extracted; being a sulphide, it is concentrated by froth flotation and then roasted to the oxide before reduction.

Malleability is the property of being beaten into thin sheets and ductility the property of being drawn into wires, and gold possesses both to the highest degree of any metal: a single gram can be beaten into a sheet of about one square metre and drawn into a wire of…

Zone 6 covers the far south of the peninsula together with the Lakshadweep islands, so PIN codes in Thiruvananthapuram and Chennai both begin with 6.

India Post Payments Bank was launched on 1 September 2018 and is wholly owned by the Government of India under the Department of Posts.

The post office at Hikkim, a village in the Lahaul and Spiti district, stands at roughly 14,567 feet and is counted as the highest in the world; mail from it is carried down the valley on foot and by road.

The post office was opened in 2011 on a houseboat on the Dal Lake in Jammu and Kashmir and is the first of its kind anywhere in the world, offering ordinary counter services along with a small philately museum.

India joined the Universal Postal Union on 1 July 1876 and was the first country in Asia to do so, which gave Indian mail access to the Union's common rules for international post.

The Universal Postal Union was created by the Treaty of Bern signed on 9 October 1874, and the anniversary of that treaty is kept as World Post Day; India observes National Postal Week from this date.

Passed while Lord Dalhousie was Governor-General, it made the posts an all-India department, created the post of Director General of Post Offices and fixed postage by the weight of a letter alone, so that distance no longer mattered.

It was issued in 1852 in the province of Sind by Sir Bartle Frere, its Commissioner, and was the first adhesive postage stamp brought out anywhere in Asia.

Zone 9 is the only one of the nine PIN zones that is functional rather than geographical: it covers Army Post Office and Field Post Office addresses wherever the units concerned are posted, so that mail to serving personnel need not disclose their location.