Railway 2025 Previous Year GK Questions with Answers

The correct answer is B, Iron rod. An iron rod is a solid, and the force of attraction between particles is strongest in the solid state.

In a solid the particles sit close together in fixed positions and can only vibrate, so a solid keeps its shape, has a definite volume and can hardly be compressed. In a liquid the attraction is weaker, so the particles slide over one another and the liquid takes the shape of its vessel while keeping its volume. In a gas the attraction is weakest and the particles move freely at high speed, so a gas fills any container and is easily compressed. The same order explains why solids have the highest density and gases the lowest.

Option A is wrong because water is a liquid with medium attraction. Option C is wrong because alcohol is also a liquid, and it evaporates faster than water. Option D is wrong because oxygen is a gas, where the attraction between particles is the weakest of all.

Exam tip: force of attraction is solid greater than liquid greater than gas, and the freedom of particles runs the other way.

The correct answer is C, Breaking a chalk stick. Force has to be applied to break the chalk because its particles hold one another together, and that pull is the force of attraction between particles.

Every substance is made of particles that attract one another, and the strength of that attraction decides how hard a thing is to break. The attraction is strongest in solids, less in liquids and least in gases, which is why an iron rod needs a hammer, water can be separated with a finger and air offers no resistance at all. The school activity of breaking chalk, then a pencil and then an iron nail shows the difference in this force from one solid to another.

Option A is wrong because compressing a sponge only squeezes out the air in its pores. Option B is wrong because dissolving sugar shows diffusion and the spaces between particles. Option D is wrong because heating ice shows a change of state, not the attraction itself.

Exam tip: attraction between particles is strongest in solids, weaker in liquids and weakest in gases.

The correct answer is Article 52, which says simply: "There shall be a President of India." It opens Chapter I of Part V, the chapter on the Union executive, and every other rule about the office builds on it.

The other options are the Articles around it, which is why they are chosen to confuse. Article 53 vests the executive power of the Union in the President and makes the President the Supreme Commander of the defence forces; it describes what the office does, not that it exists. Article 74 provides the Council of Ministers headed by the Prime Minister to aid and advise the President. Article 75 deals with the appointment of the Prime Minister and other ministers. A quick way to hold the sequence: 52 creates the office, 53 gives it the executive power, 54 and 55 say how the President is elected, and 74 and 75 bring in the Prime Minister and the Council of Ministers.

The correct answer is C, Tim Wigmore. Test Cricket: A History, published in 2025, was written by the English cricket writer and journalist Tim Wigmore. The book follows the game's longest format from the first Test between England and Australia at Melbourne in March 1877 down to the present day, covering how Test cricket spread across countries, how it changed from era to era, and the pressure it now faces from the shorter formats. Wigmore also co-wrote Cricket 2.0, a study of Twenty20 cricket that was named Wisden Book of the Year. A is wrong because Michael Atherton, the former England captain, writes widely on cricket but not this book. B is wrong because Gideon Haigh is an Australian cricket historian with many other titles to his name. D is wrong because Ramachandra Guha wrote A Corner of a Foreign Field and other works on Indian cricket and history. Exam tip: Tim Wigmore - Test Cricket: A History in 2025 and Cricket 2.0 on Twenty20 cricket.

The correct answer is C, To manage hardware and software resources. An operating system is the system software that loads when a laptop starts and then runs the machine: it shares out memory, decides which program gets the processor and for how long, keeps files and folders in order on the disk, talks to the keyboard, screen and printer through device drivers, and gives the user an interface. Every other program, from a word processor to a game, runs on top of it and asks it for whatever it needs. Windows, macOS, Linux, Ubuntu and Android are common examples. A is wrong because typing documents is the work of an application such as MS-Word. B is wrong because a browser is only one of many programs the operating system supports, not its purpose. D is wrong because video editing is done by application software such as a video editor. Exam tip: an operating system is system software and works as the bridge between the user, the applications and the hardware.

The correct answer is B, Dhammapada. The Dhammapada gathers the Buddha's teaching into 423 short verses arranged in 26 chapters, and because it holds the heart of the doctrine in verses anyone can remember, it is often called the Gita of Buddhism. It is written in Pali and belongs to the Khuddaka Nikaya, one of the five nikayas of the Sutta Pitaka. Its chapters deal with the mind, anger, craving, the wise and the fool, and the path to nirvana. A is wrong because Mahayana Sutra is not one book but a whole class of later Sanskrit texts. C is wrong because the Vamsatthappakasini is a Sri Lankan commentary on the Mahavamsa chronicle, a work of history rather than teaching. D is wrong because the Saddharmapundarika, the Lotus Sutra, is a major Mahayana work on the one vehicle and is much later than the Pali canon. Exam tip: Tripitaka = Vinaya Pitaka, Sutta Pitaka and Abhidhamma Pitaka; the Dhammapada sits inside the Sutta Pitaka.

The correct answer is B, Bhopal. Bhopal stands at about 23.3° North, so of the four cities it lies nearest to the 24° parallel. Bhopal is the capital of Madhya Pradesh, and the Tropic of Cancer, at 23½° North, runs across the state just to the north of the city, which is why this belt of latitude is linked with Bhopal in examinations. A is wrong because Patna, the capital of Bihar, lies near 25.6° North, more than one and a half degrees away. C is wrong because Raipur, the capital of Chhattisgarh, lies near 21.2° North, almost three degrees to the south. D is wrong because Dispur, the capital of Assam, lies near 26.1° North and is the farthest of the four from the given latitude. One degree of latitude is about 111 km on the ground, so these differences are large. Exam tip: the Tropic of Cancer crosses eight states — Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram.

The correct answer is D, 14 years. Article 24 says that no child below the age of 14 years shall be employed to work in any factory or mine or in any other hazardous employment. It is part of the Right against Exploitation (Articles 23 and 24) among the Fundamental Rights in Part III. Article 23 bans trafficking in human beings and forced labour (begar). Article 24 goes with Article 21A, added by the 86th Amendment in 2002, which gives free and compulsory education to children aged 6 to 14. The Child Labour (Prohibition and Regulation) Amendment Act, 2016 bans employing children below 14 in any work and adolescents aged 14 to 18 in hazardous work. A is wrong because 18 is the voting age and the age of adulthood, not the limit in Article 24. B is wrong because the Constitution does not use 16 as the limit. C is wrong because 12 is lower than the age fixed by Article 24. Exam tip: Article 23 = no trafficking or forced labour; Article 24 = no child below 14 in factories, mines or hazardous work; Article 21A = education for ages 6 to 14.

The correct answer is B, 010010. The 2's complement of a binary number is found in two steps: flip every bit to get the 1's complement, then add 1. Flipping 101110 gives 010001, and 010001 + 1 = 010010. A quick check confirms it: 101110 is 46 and 010010 is 18, and 46 + 18 = 64, which is 2⁶ for a six-bit number, exactly as it should be. Computers use the 2's complement to store negative numbers and to do subtraction by addition, which keeps their circuits simple. A shortcut also works: copy the bits from the right up to and including the first 1, then flip all the rest. A is wrong because 010011 adds 2 instead of 1 to the 1's complement. C is wrong because 110001 leaves the leftmost bit unflipped. D is wrong because 010001 is only the 1's complement; the final +1 is missing. Exam tip: 2's complement = flip all bits, then add 1; a number plus its 2's complement equals 2ⁿ.

The correct answer is B, To prevent unauthorised access to a private network. A firewall stands between a trusted private network and an untrusted one such as the internet, and checks the data going in and out. Traffic that matches its security rules is allowed and the rest is blocked, much like a guard at a gate. It can be hardware, such as a separate device or a feature of a router, or software, such as the firewall built into Windows. The name comes from the fire-resistant walls in buildings that stop a fire from spreading from one part to another. A is wrong because a firewall does not make the connection faster; checking traffic can even slow it slightly. C is wrong because finding and removing viruses is the job of antivirus software, which works on files already on a computer. D is wrong because storing passwords safely is the work of a password manager. Exam tip: firewall = gatekeeper of network traffic; antivirus = cleaner of infected files.

The correct answer is A, SRAM. Static RAM stores each bit in a flip-flop circuit made of several transistors, usually six, so the bit stays put as long as the power is on and never needs refreshing. That makes SRAM very fast, but also costly and bulky, so it is used in small amounts as cache memory inside the processor. Both kinds of RAM are volatile and lose their data when the power goes off. B is wrong because DRAM stores each bit as a charge in a tiny capacitor that slowly leaks, so it must be refreshed every few milliseconds; it is cheaper and denser, and serves as the main memory. C is wrong because flash memory is non-volatile storage used in pen drives, memory cards and SSDs, and it is slower than RAM. D is wrong because ROM is read-only, non-volatile memory that holds start-up instructions, not a type of RAM. Exam tip: SRAM = static, fast, no refresh, used as cache; DRAM = dynamic, needs refresh, used as main memory.

The correct answer is D, Hard Disk. A hard disk is a secondary storage device that keeps programs and files permanently, even when the power is off, and it sits outside the processor. The CPU (Central Processing Unit), often called the brain of the computer, is made of the Arithmetic Logic Unit, the Control Unit and a set of small, very fast registers. Modern processors also carry cache memory on the same chip to hold the data and instructions they need most often. Data from the hard disk is first loaded into RAM, then moved into the cache and registers before the CPU works on it. A is wrong because the ALU does all arithmetic and logical work such as addition and comparison. B is wrong because the Control Unit fetches and decodes instructions and directs every operation. C is wrong because cache memory is built into the processor chip and is the fastest memory after the registers. Exam tip: CPU = ALU + CU + registers (with cache); hard disk = secondary storage.

The correct answer is A, F5. In Microsoft PowerPoint, pressing F5 starts the slide show from the first slide, whichever slide you are working on at that moment. The same command sits on the Slide Show tab as 'From Beginning'. Its close partner is Shift + F5, which starts the show from the current slide, and paper setters like to place the two side by side. During the show, Esc ends the presentation, and pressing B or the full stop key turns the screen black until you press it again. B is wrong because Alt + Tab switches between open windows in Windows. C is wrong because Ctrl + P opens the Print option in almost every Office program. D is wrong because Shift + F5 begins the show from the current slide, not from the beginning. Exam tip: F5 = start from the beginning, Shift + F5 = start from the current slide, Esc = end the show.

The correct answer is Article 48A. Added by the 42nd Amendment in 1976, it says the State shall endeavour to protect and improve the environment and to safeguard the forests and wildlife of the country. The same amendment added a matching Fundamental Duty in Article 51A(g), asking every citizen to protect and improve the natural environment, including forests, lakes, rivers and wildlife. Laws such as the Wildlife (Protection) Act, 1972 and the Forest (Conservation) Act, 1980 give effect to this goal.

The other options are the Articles right next to it. Article 48 asks the State to organise agriculture and animal husbandry on modern lines and to prohibit the slaughter of cows, calves and other milch and draught cattle. Article 47 is about nutrition, public health and the prohibition of intoxicating drinks. Article 49 is about protecting monuments of national importance. Remember the pair: the State's duty to the environment is Article 48A, and the citizen's duty is Article 51A(g).

The correct answer is Eighty-sixth Amendment Act, 2002. Originally Article 45 asked the State to provide free and compulsory education for all children until they reached fourteen, within ten years. The 86th Amendment moved that promise into the Fundamental Rights as Article 21A, covering children aged six to fourteen, and rewrote Article 45 so that it now asks the State to provide early childhood care and education for all children until they complete six years. The same amendment added the Fundamental Duty in Article 51A(k), asking parents to educate their children.

The 42nd Amendment (1976) added Articles 39A, 43A and 48A but did not touch Article 45. The 74th Amendment (1992) created the constitutional framework for municipalities. The 44th Amendment (1978) removed the right to property and added Article 38(2). So when a question pairs "below six years" with an amendment, the answer is the 86th; when it pairs "six to fourteen" with a Fundamental Right, the answer is Article 21A.

The correct answer is Article 43 B. The 97th Amendment Act, 2011 was about co-operative societies, and it touched three Parts of the Constitution. It added "co-operative societies" to the freedom of association in Article 19(1)(c), a Fundamental Right; it inserted Article 43B, a Directive Principle asking the State to promote the voluntary formation, autonomous functioning, democratic control and professional management of co-operative societies; and it added a new Part IXB on co-operative societies.

The other options were all added by the 42nd Amendment in 1976, not by the 97th. Article 48A is about protecting the environment, forests and wildlife; Article 39A is about equal justice and free legal aid; and Article 43A is about the participation of workers in the management of industries. So there are two "43" Articles with letters: 43A for workers (1976) and 43B for co-operatives (2011). Keeping these two apart is what the question really tests.

The correct answer is Article 39(d). Article 39 lists several principles the State should direct its policy towards, and clause (d) asks it to secure equal pay for equal work for both men and women. Parliament gave effect to it through the Equal Remuneration Act, 1976, whose provisions are now part of the Code on Wages, 2019, and the Supreme Court has also treated equal pay for equal work as flowing from Articles 14 and 16.

The other options are real Directive Principles on related subjects, which is why they mislead. Article 39(a) is about an adequate means of livelihood for all citizens, men and women equally. Article 42 asks for just and humane conditions of work and maternity relief. Article 43 is about a living wage and a decent standard of life for workers. A good way to separate them: 39(a) livelihood, 39(d) equal pay, 42 working conditions and maternity, 43 living wage.