RRB Group D GK Questions 2026

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.

The first of the six digits identifies one of the nine postal regions or zones into which the country is divided for the purpose of the PIN.

He was an Additional Secretary in the Union Ministry of Communications and a Sanskrit scholar, and he worked out the six-digit code that came into use on 15 August 1972.

The six-digit Postal Index Number was brought into use on 15 August 1972 to replace the practice of writing out long postal addresses that often repeated place names found in several states.

The minister cited this estimate to show how much livelihood depends on the sector, which is the reason seed quality and modern infrastructure matter well beyond the rearing shed.

The trap here is option C: 74 per cent is Assam’s share of Eri silk production, amounting to 2,131 metric tonnes, and the two shares are routinely swapped in question papers, so the pairing must be learnt together.