RRB JE 2019 Previous Year GK Questions with Answers

The correct answer is B, International Union of Pure and Applied Chemistry, known by its short form IUPAC. It is the world authority on chemical nomenclature, so it approves the names and symbols of newly discovered elements, standardises the naming of compounds and maintains the recommended values of atomic weights. Elements such as oganesson and nihonium received their names through this body after the discovery claims were verified.

Option A, UNESCO, promotes education, science and culture but does not name elements. Option C, the International Science Council, brings scientific bodies together for policy and cooperation and has no naming power. Option D, the International Union of Geodesy and Geophysics, works on the study of the earth, its shape, gravity and interior, and so is unrelated to chemical names, although its own abbreviation looks similar.

The correct answer is C, National Aeronautics and Space Administration. NASA is the civilian space agency of the United States, established in 1958 after the launch of Sputnik, with its headquarters at Washington DC. It grew out of an older body for aeronautical research, which is why aeronautics appears in the name before space. Its famous programmes include Apollo, which landed humans on the Moon, the Space Shuttle, the Hubble and James Webb telescopes, the Mars rovers and the Artemis programme.

Option A rearranges the words into Agency of Space Administration, which is not the official name. Option B replaces National with Navigational, a word that belongs to satellite navigation rather than to the agency. Option D is the closest trap because it ends with Agency instead of Administration; the last word of the name is Administration, and getting that single word right is what the question tests.

The correct answer is B, STUDSAT. STUDSAT, short for Student Satellite, was the first pico satellite built in India. A pico satellite is one that weighs under about one kilogram, and STUDSAT weighed less than that. It was built by students of engineering colleges in Bengaluru and Hyderabad and was launched in 2010 by a PSLV flight as an auxiliary payload, carrying a small camera for imaging the Earth.

Option A, INSAT, is not a single satellite but the Indian National Satellite System, a family of heavy communication satellites in geostationary orbit. Option C, GSAT-4, was an experimental communication satellite that was lost when its launch vehicle failed in 2010. Option D, ANUSAT, was built by Anna University and launched in 2009, but it was a micro satellite of about forty kilograms, not a pico satellite, which is exactly the distinction the question is testing.

The correct answer is B, To. The To field of a mail window is meant for the addresses of the people the letter is written to. More than one address can be typed there, separated by commas, and every recipient can see the whole list. Copies can also be sent through the Cc field, which all recipients see, or the Bcc field, which no other recipient sees.

Option A, Subject, is the one-line heading that tells the reader what the letter is about, and an address typed there would never be treated as a destination. Option C, Message, is the body of the letter, where the matter is written. Option D, From, shows the sender's own address and is filled in automatically by the mail service, so it names the writer and not the reader. Hence only the To field carries the recipients' addresses.

The correct answer is D, F5. Pressing F5 anywhere in a presentation closes the editing window and runs the slide show from slide one, whichever slide you were working on. To begin instead from the slide on the screen, the key is Shift + F5, and the pair F5 and Shift + F5 should always be learnt together.

Option A, Alt + F5, does not start an ordinary show from the beginning; in recent versions it opens Presenter View, where the speaker sees notes and a timer. Option B, Ctrl + P, is the print command in editing view, and inside a running show it turns the mouse pointer into a pen for writing on the slide, so it never starts the show. Option C, Alt + Tab, belongs to Windows rather than PowerPoint and merely switches between the open programs on the taskbar.

The correct answer is A, Fluorine. Electronegativity is the tendency of an atom to attract a shared pair of electrons towards itself. It increases from left to right across a period, as nuclear charge grows, and decreases down a group, as each new shell puts the outer electrons further from the nucleus. Fluorine stands at the top of group 17 and is the smallest halogen, so it holds a shared pair most tightly and is the most electronegative element of all, with a value of about 4.0 on the Pauling scale. Options B, C and D are wrong because bromine, iodine and chlorine all lie below fluorine in the same group, and electronegativity falls as you go down, in the order fluorine, then chlorine, then bromine, then iodine. Remember also that fluorine is the most electronegative element in the whole table, not merely among the halogens, and that caesium is among the least electronegative.

The correct answer is B, potential difference. The potential difference between two points in a circuit is defined as the work done in moving a unit positive charge from one point to the other. From this definition comes the unit: one volt is one joule of work per coulomb of charge, and the quantity is measured with a voltmeter connected in parallel across the two points.

Option A, pressure distance, is not a physical quantity at all, and pressure belongs to mechanics rather than to circuits. Option C, potential distance, is likewise not a defined term; the word potential appears only to make the option look plausible. Option D, pressure difference, is a real quantity but belongs to fluids, where it drives the flow of a liquid or a gas; it is sometimes used only as an analogy for voltage while teaching, never as the name of the electrical quantity. The definition asked for is that of potential difference.

The correct answer is D, it gets halved. By Ohm's law, at a constant temperature the current through a conductor is directly proportional to the potential difference across its ends, since the current equals the potential difference divided by the resistance. The resistance of the conductor does not change when the voltage is changed, so halving the potential difference halves the current exactly.

Option A is wrong because a smaller driving voltage cannot push a larger current through the same resistance. Option B is wrong for the same reason, and it describes what would happen if the voltage were doubled rather than halved. Option C, that the current gets decreased, is true as far as it goes but it is not the best answer, because the question can be answered exactly: the current does not merely fall, it falls to one half. In a question of this kind always give the precise proportional change rather than the vague direction of change.

The correct answer is B, 2001. The Stockholm Convention was adopted in 2001 and came into force in 2004. It aims to eliminate or restrict persistent organic pollutants, chemicals such as some pesticides and industrial compounds that resist breaking down, travel long distances, accumulate in fatty tissue and harm human health; the original list was known as the dirty dozen. India is a party to the convention.

Option A, 2000, is the year of the Cartagena Protocol on biosafety, made under the Convention on Biological Diversity, and is easy to confuse. Option C, 1998, is the year of the Rotterdam Convention on prior informed consent for hazardous chemicals in trade, which is a related but separate treaty. Option D, 1999, has no major chemical convention attached to it. The chemical trio worth memorising is Basel in 1989 on hazardous waste, Rotterdam in 1998 on trade in chemicals, and Stockholm in 2001 on persistent organic pollutants.

The correct answer is B, IUCN, the International Union for Conservation of Nature. Founded in 1948 and based in Switzerland, it maintains the Red List of Threatened Species, which grades species as least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild or extinct. It is the standard reference used by governments and by examiners.

Option A, the United Nations Organisation, is the parent body of many agencies but does not itself compile the list; its environment arm, the United Nations Environment Programme, works with IUCN rather than replacing it. Option C, the World Health Organisation, deals with human health and disease. Option D, the World Wide Fund for Nature, is a conservation organisation known for its panda emblem and for the Living Planet Report, and it is the commonest wrong choice here because it works in the same field, but the Red List belongs to IUCN.

The correct answer is 6 months. Article 85(1) says the President shall summon each House to meet at such time and place as he or she thinks fit, but six months shall not intervene between its last sitting in one session and the date appointed for its first sitting in the next session. So Parliament must meet at least twice a year. In practice it holds three sessions: the Budget session (February to May), the Monsoon session (July to September) and the Winter session (November to December).

The other options mix this rule up with other time limits. Three months has no basis, one year would allow Parliament to go an entire year without meeting, and nine months is invented. The six-month rule also explains the maximum life of an ordinance: because Parliament must reassemble within six months, and an ordinance lapses six weeks after reassembly, no ordinance can last longer than six months and six weeks. Note that the rule is about the gap between sessions, not about the length of a session.

The correct answer is A, Program counter. In the 8085A microprocessor the program counter is a 16-bit register that always holds the memory address of the next instruction, or op-code, to be fetched. After each fetch it is incremented automatically, and a jump or call instruction loads a new address into it so that control moves elsewhere in the program. Two other registers of the 8085 are often confused with it. The accumulator is the 8-bit register A in which arithmetic and logic results are stored. The stack pointer is a 16-bit register holding the address of the top of the stack, used while saving return addresses and register contents. B and C are wrong for those reasons. D is wrong because instruction pointer is the name Intel's later x86 processors use for the same idea; the 8085 register is called the program counter. Exam tip: 8085 has an 8-bit accumulator and 16-bit program counter and stack pointer.

The correct answer is C, LSI. Integrated circuits are classified by how many logic gates are packed on a single chip. Small scale integration, SSI, holds up to about 10 or 12 gates; medium scale integration, MSI, holds roughly 12 to 100; large scale integration, LSI, holds more than 100 and up to about 1000; and very large scale integration, VLSI, holds thousands or more, which is the level used for today's microprocessors. So a chip carrying more than 100 gates is described as LSI. This ladder also maps onto the generations of computers: the third generation used SSI and MSI integrated circuits, while the fourth generation brought LSI and VLSI and with them the microprocessor. A is wrong because MSI stops at about 100 gates. B is wrong because SSI holds only a handful. D is wrong because VLSI begins in the thousands of gates. Exam tip: SSI up to 10, MSI up to 100, LSI up to 1000, VLSI beyond that.

The correct answer is C, Ready queue. In an operating system a process passes through the states new, ready, running, waiting and terminated. The processes that are already loaded in main memory and are only waiting for the processor are kept in a list called the ready queue, and the short term scheduler picks the next process from it using a policy such as first come first served, shortest job first or round robin. Two other lists are worth remembering. The job queue holds all the processes in the system, including those still on disk waiting to be brought into memory. A device or waiting queue holds processes blocked for an input or output operation. A is wrong because process queue is not the standard name for this list. B is wrong because the job queue is the wider list of every process in the system. D is wrong because execution queue is not a recognised term. Exam tip: job queue is all processes, ready queue is in memory waiting for the CPU.

The correct answer is D, Tunnel diode. A tunnel diode, also called an Esaki diode after Leo Esaki who made it in 1957, is heavily doped on both sides, so its depletion layer is extremely thin and electrons cross it by quantum tunnelling. Over part of its forward characteristic the current falls as the voltage rises, giving a negative resistance region, and it is this property that lets the diode both amplify a signal and sustain oscillations in a circuit. It switches extremely fast and is used in microwave oscillators and high frequency circuits. A is wrong because a point contact diode is used to detect and rectify high frequency signals. B is wrong because a Zener diode works in reverse breakdown and is used to regulate voltage. C is wrong because an ordinary junction diode only rectifies, allowing current one way. Exam tip: tunnel diode means negative resistance, so it can amplify and oscillate; Zener diode means voltage regulation.

The correct answer is C, All of the options. The system development life cycle, or SDLC, is the set of stages followed while building a software system, and feasibility study, coding and implementation are all stages of it. The usual order is preliminary investigation and feasibility study, then requirement analysis, then system design, then coding or development, then testing, then implementation, and finally maintenance. The feasibility study checks whether the proposed system is workable in technical, economic and operational terms before money is spent; coding turns the design into program instructions; implementation installs the finished system and moves users onto it. A, B and D are each wrong only because they name a single stage, while the question asks which of them belong to the life cycle and all three do. Exam tip: remember the SDLC order as feasibility, analysis, design, coding, testing, implementation, maintenance.

The correct answer is B, Product of the masses of objects M × m. Newton's universal law of gravitation states that every two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them, written F = GMm/d². Here G is the universal gravitational constant, whose value is 6.67 × 10⁻¹¹ newton metre squared per kilogram squared. So doubling either mass doubles the force, while doubling the distance cuts the force to one fourth. A is wrong because the law multiplies the masses instead of adding them. C is wrong because a difference of masses would make the force vanish for two equal bodies, which never happens. D is wrong because no square of a mass appears in the formula; only the distance is squared. Exam tip: F = GMm/d², directly proportional to the product of masses and inversely to the square of the distance.

The correct answer is C, Hit ratio. Cache memory is the small, very fast memory placed between the processor and main memory that keeps the data the processor is most likely to need next. When the processor finds the word it wants in the cache it is called a hit, and when it does not it is a miss that must be fetched from slower main memory. The hit ratio is the number of hits divided by the total number of memory references, so a higher hit ratio means a faster system; it is the standard measure of cache performance. A is wrong because a register is a storage location inside the CPU, not a measure. B is wrong because associative mapping is a way of placing blocks in the cache. D is wrong because set-associative mapping is likewise a mapping technique, not a performance figure. Exam tip: hit ratio = hits ÷ total references; cache mapping types are direct, associative and set-associative.

The correct answer is C, Extended Binary Coded Decimal Interchange Code. EBCDIC is an 8-bit character encoding scheme developed by IBM in 1963 for its mainframe and midrange computers. Because it uses 8 bits for each character it can represent 256 different characters, twice as many as the 7-bit ASCII code, which handles 128. EBCDIC grew out of the older Binary Coded Decimal system and is still found on IBM mainframes, while ASCII became the standard for personal computers and Unicode now covers the scripts of the world, including Devanagari. A is wrong because the third word is Coded, not Control. B is wrong on two counts: the first word is Extended and the third is Coded. D is wrong because the expansion ends with Decimal Interchange Code, not Data Integration Code. Exam tip: EBCDIC is 8-bit and 256 characters, ASCII is 7-bit and 128 characters, Unicode is 16-bit and covers all scripts.

The correct answer is B, Half-duplex. Data can travel between two devices in three modes. In half-duplex mode both devices can send and receive, but only one of them may transmit at any given moment, so the traffic takes turns; a walkie-talkie is the standard example, and older hubs and CB radio worked the same way. In simplex mode data moves in one direction only, as from a keyboard to the computer or from a radio station to a receiver. In full-duplex mode both sides can send and receive at the same time, as in a telephone call or on a modern switched network. A is wrong because simplex allows no return traffic at all. C is wrong because three-quarters duplex is not a recognised mode. D is wrong because only one of the listed modes fits the description. Exam tip: simplex is one way, half-duplex is both ways by turns, full-duplex is both ways together.