Railway GK Questions 2026

From 5 to 9 December 1952 an anticyclone settled over London, a temperature inversion trapped the smoke and sulphur dioxide of domestic coal fires, and the resulting smog killed thousands.

The Minamata Convention on Mercury was adopted at Kumamoto, Japan, in 2013 and entered into force in 2017.

Mining waste carrying cadmium entered the Jinzu river in Toyama Prefecture and reached people through irrigated rice and drinking water.

The Chisso Corporation discharged methylmercury compounds into Minamata Bay in Kumamoto Prefecture; the mercury accumulated through fish and shellfish into the people who ate them and attacked the central nervous system, producing numbness, loss of coordination, blindness and congenital deformity.

Reactor Number 4 of the Chernobyl Nuclear Power Plant, near the town of Pripyat, exploded on 26 April 1986. The site then lay in the Ukrainian Soviet Socialist Republic of the USSR and lies in independent Ukraine today, which is why the question is usually framed as present-day country.

The leak at the Union Carbide India Limited plant in Bhopal began late on 2 December 1984 and the gas spread through the early hours of 3 December, which is why India observes 2 December as National Pollution Control Day.

Methyl isocyanate, or MIC, was stored at the Union Carbide India Limited plant in Bhopal as an intermediate for making the pesticide carbaryl.

In black-box testing the tester treats the program as a sealed box, supplies inputs drawn from the specification and compares the outputs with what the specification promises; equivalence partitioning and boundary value analysis are its standard techniques, and no knowledge of the source code is needed.

A code walk-through is an informal review technique: a few team members read a module line by line, mentally execute it on sample data and note the defects they find, without the checklists, metrics and formal records of an inspection.

Boehm described the spiral model, in which the project moves outward through repeated loops and each loop performs four activities: determining objectives, risk analysis and resolution, development and testing, and planning the next loop.

If one module must know the internal data or logic of another to work, the two are tightly coupled, and a change in one forces a change in the other.

This is the first phase of the SDLC: the team meets the users, records what the system must do and what constraints apply, and sets it all down in the Software Requirements Specification, which then becomes the agreed basis for everything that follows and the yardstick for acceptance testing.

The Waterfall model is called the linear sequential model because the project flows in one direction through requirement analysis, design, coding, testing, deployment and maintenance, with each phase completed and signed off before the next begins and no overlap between them.

Binary search compares the key with the middle element and throws away half the array at every step, so the number of comparisons grows with the logarithm of the array size; an array of a million sorted items needs about twenty comparisons.

Muhammad ibn Musa al-Khwarizmi was a ninth-century Persian mathematician and astronomer whose treatise on calculation with Hindu-Arabic numerals reached Europe in Latin translation; his Latinised name produced the word algorithm, and another of his works gave the word algebra.

The oval is the terminal symbol, and a well-formed flowchart has exactly one Start terminal and at least one Stop terminal; a chart that can never reach a Stop describes an infinite loop and so breaks the finiteness property of an algorithm.

The diamond or rhombus is the decision symbol: it holds a condition and has one entry with two exits, marked Yes and No, so the flow branches according to the test.

The two manuscripts were inscribed on the International Register in April 2025 on a nomination made by the Ministry of Culture, and both are in the custody of the Bhandarkar Oriental Research Institute in Pune.

The Rigveda manuscripts, preserved at the Bhandarkar Oriental Research Institute in Pune, were inscribed on the International Register in 2007 as a record of one of the oldest surviving bodies of religious poetry anywhere.

UNESCO set up the Memory of the World Programme in 1992, after recognising that war, neglect, damp, insects and illegal trade were destroying archives and manuscript collections across the world.