RRB Group D 2018 Previous Year GK Questions with Answers

The correct answer is C, 500 W. The work done against gravity is mgh = 40 × 10 × 5 = 2000 joule, and power is work divided by time, so 2000 ÷ 4 = 500 watt.

Power is the rate of doing work, measured in watt, where one watt is one joule per second. In climbing stairs the useful work is the gain in potential energy, mgh, where only the vertical rise counts and the length of the staircase does not matter. If the same girl ran up in 2 seconds the work would be the same 2000 joule but the power would double to 1000 watt, which shows that power depends on how fast the work is done.

Option A is wrong because 100 W comes from dividing by the wrong quantity. Option B is wrong because 200 W would need 10 seconds. Option D is wrong because 2000 is the work in joule, not the power in watt.

Exam tip: work = mgh, power = work ÷ time, and one horsepower is about 746 watt.

The correct answer is C, zero. Constant velocity means no acceleration, and by Newton's second law force equals mass into acceleration, so the net force must be zero.

Newton's first law says a body continues in its state of rest or of uniform motion in a straight line unless an external force acts on it, which is why motion at a steady speed in a fixed direction needs no force to keep it going. Force is needed only to change the speed or the direction. A car moving at a steady 60 km per hour on a straight road is in the same state: the engine's push only balances friction and air resistance, so the forces cancel and the net force is zero. Such a body is said to be in equilibrium.

Options A, B and D are wrong because any net force in a direction would produce acceleration and so change the velocity, which contradicts the given condition of constant velocity.

Exam tip: constant velocity means zero acceleration and therefore zero net force, not zero force at all.

The correct answer is B, Platinum. Platinum is the least reactive of the four, so it is found in nature in the free or native state as the metal itself.

A metal occurs free only when it does not react with the air, water and other substances around it. In the reactivity series the metals at the bottom - gold, platinum and silver - are called noble metals and are found native; those higher up occur as oxides, sulphides or carbonates and must be extracted from their ores. This is why gold nuggets are found in river sand while aluminium has to be won from bauxite by electrolysis.

Option A is wrong because copper is mostly mined as copper pyrites and other ores, though small native deposits do exist. Option C is wrong because iron is always found as an oxide such as haematite or magnetite. Option D is wrong because potassium is so reactive that it burns on contact with water and is never found free.

Exam tip: gold, platinum and silver occur native; the more reactive a metal, the more firmly it stays locked in its ore.

The correct answer is C, Manipur. M. C. Mary Kom was born in Kangathei village of Churachandpur district in Manipur.

Mary Kom is the only woman boxer to have won six world championship titles, and she is nicknamed Magnificent Mary. She took the bronze medal in the flyweight class at the London Olympics of 2012, the first Indian woman boxer to win an Olympic medal, and she has also won gold at the Asian Games of 2014 and the Commonwealth Games of 2018. She received the Arjuna Award, the Padma Shri, the Rajiv Gandhi Khel Ratna and the Padma Vibhushan, and served as a nominated member of the Rajya Sabha.

Option A is wrong because Mizoram is best known in Indian sport for footballers. Option B is wrong because Assam is the home state of the boxer Shiva Thapa and the sprinter Hima Das. Option D is wrong because Meghalaya has produced no boxer of this record.

Exam tip: Mary Kom of Manipur, six world titles, bronze at London 2012, called Magnificent Mary.

The correct answer is D, Intermolecular forces are weak. Melting and boiling only have to break the weak forces between the molecules, not the strong bonds inside them, so little heat is needed.

A covalent bond is formed by the sharing of electrons and is itself strong, but it acts only within the molecule. Separate molecules are held to one another by weak van der Waals forces, and these give way at low temperature, which is why water, ammonia, carbon dioxide and most organic compounds melt and boil easily. Ionic compounds such as sodium chloride behave in the opposite way: a strong electrostatic force runs through the whole crystal, so their melting points are very high. Giant covalent solids like diamond and silicon carbide are the exception, since their bonds form a continuous network.

Options A, B and C are wrong because they all claim the forces between molecules are medium or strong, which would raise the melting and boiling points instead of lowering them.

Exam tip: strong bond inside the molecule, weak force between molecules, so covalent compounds melt at low temperature.

The correct answer is C, 24 J. By the work-energy theorem the work done equals the change in kinetic energy, which is half of 1.0 into 8 squared minus 4 squared, that is 0.5 × (64 - 16) = 24 joule.

Kinetic energy is given by half m v squared, so at 4 m/s the object has 8 joule and at 8 m/s it has 32 joule; the force must supply the difference of 24 joule. Note that doubling the speed makes the kinetic energy four times, because the speed is squared. The work-energy theorem holds whatever the path taken, which is why the question can be solved without knowing the force or the distance.

Option A is wrong because 8 joule is only the starting kinetic energy. Option B is wrong because 32 joule is the final kinetic energy, not the change. Option D is wrong because 16 joule comes from taking half of the difference of the squares of the speeds incorrectly.

Exam tip: work done = final kinetic energy minus initial kinetic energy, and doubling speed makes kinetic energy four times.

The correct answer is D, Lead and tin. Solder is an alloy of lead and tin, usually in nearly equal parts.

An alloy is a mixture of a metal with one or more other elements, made to gain a property the pure metal lacks. Solder is useful because the mixture melts at a far lower temperature than either lead or tin alone, so it flows easily and is used to join wires and electrical joints. Other alloys asked in papers are brass, made of copper and zinc, bronze of copper and tin, stainless steel of iron, chromium and nickel, and German silver of copper, zinc and nickel.

Option A is wrong because lead with copper is not the soldering alloy. Option B is wrong because tin with iron gives tin plating, used for tin cans. Option C is wrong because lead and iron together are not used as solder.

Exam tip: solder is lead plus tin and melts at a low temperature; brass is copper and zinc, bronze is copper and tin.

The correct answer is D, Madhya Pradesh. The Bansagar Dam stands on the Sone river in the Shahdol region of Madhya Pradesh.

Bansagar is a joint project of Madhya Pradesh, Uttar Pradesh and Bihar, the three states through which the Sone flows, and it serves both irrigation and power. The Sone is a major right bank tributary of the Ganga; it rises near Amarkantak, the same highland that gives birth to the Narmada, and joins the Ganga near Patna. The dam is named after the sage Bana, who is linked in tradition with the Sone valley.

Option A is wrong because Maharashtra has Koyna and Jayakwadi. Option B is wrong because Gujarat has the Sardar Sarovar on the Narmada and Ukai on the Tapi. Option C is wrong because Andhra Pradesh has Nagarjuna Sagar and Srisailam on the Krishna.

Exam tip: Bansagar on the Sone in Madhya Pradesh, shared with Uttar Pradesh and Bihar; Amarkantak is the source of both the Narmada and the Sone.

The correct answer is C, Kesari. Bal Gangadhar Tilak started Kesari in 1881 and used it to carry the message of swaraj to Marathi readers.

Tilak brought out two papers from Pune in the same year, Kesari in Marathi and Maratha in English. His writings in Kesari on the Bengal partition and on the Muzaffarpur bomb case led to a charge of sedition, and in 1908 he was sentenced to six years of transportation to Mandalay in Burma. It was Tilak who declared that swaraj is my birthright and I shall have it, and he began the public Ganapati and Shivaji festivals to reach ordinary people.

Option A is wrong because Yugantar was started in Bengali by Barindra Kumar Ghosh and Bhupendranath Datta. Option B is wrong because the Bengalee was edited by Surendranath Banerjee. Option D is wrong because Amrita Bazar Patrika was founded by Sisir Kumar Ghosh and Motilal Ghosh.

Exam tip: Tilak - Kesari in Marathi and Maratha in English; Gandhi - Young India and Navajivan.

The correct answer is B, USA. The World Bank has its headquarters at Washington DC in the United States of America.

The World Bank and the International Monetary Fund were both set up after the Bretton Woods conference of 1944 and began work in 1945, and both have their offices in Washington DC. The Bank lends for long-term development - roads, power, irrigation, schools and health - while the IMF looks after exchange rates and short-term balance of payments trouble. The World Bank Group has five arms, of which the IBRD and the IDA together form the World Bank, and India was a founder member.

Option A is wrong because London holds the Commonwealth Secretariat and the International Maritime Organisation, not the World Bank. Option C is wrong because Tokyo is the seat of the United Nations University, while the Asian Development Bank is at Manila. Option D is wrong because Moscow hosts no such global lender.

Exam tip: World Bank and IMF at Washington DC, WTO at Geneva, ADB at Manila.

The correct answer is D, uterus. The zygote divides as it travels down the fallopian tube and the resulting ball of cells gets implanted in the thick lining of the uterus.

Fertilisation itself takes place in the fallopian tube, where a sperm fuses with the ovum to form the zygote. Repeated division turns it into an embryo, which reaches the uterus in about a week and sinks into the endometrium, the soft inner wall prepared by hormones. There the placenta develops and supplies the growing embryo with food and oxygen from the mother's blood while carrying away waste. Human pregnancy lasts about nine months.

Option A is wrong because the cervix is only the narrow neck of the uterus that opens into the vagina. Option B is wrong because the ovary produces the ovum and hormones but does not hold the embryo. Option C is wrong because the vagina is the passage that receives the sperm and later serves as the birth canal.

Exam tip: fertilisation in the fallopian tube, implantation in the uterus, nourishment through the placenta.

The correct answer is C, Mughal. Humayun's Tomb in Delhi is one of the earliest and finest examples of Mughal architecture.

The tomb was built in 1570 on the orders of Humayun's widow Bega Begum, also called Haji Begum, and the architect was Mirak Mirza Ghiyas of Persia. It was the first garden tomb in India, set in a charbagh, the four-part garden divided by water channels, and the first large structure to use red sandstone with white marble inlay and a high double dome. This plan became the model for the Taj Mahal built about eighty years later. UNESCO placed the tomb on the World Heritage list in 1993.

Option A is wrong because British architecture in India belongs to the colonial period after the eighteenth century. Option B is wrong because Chola architecture means Dravidian temples such as the Brihadeshwara temple at Thanjavur. Option D is wrong because Magadha is an ancient kingdom, not a style of tomb building.

Exam tip: Humayun's Tomb is the first garden tomb of India and the model for the Taj Mahal.

The correct answer is B, 19.8 × 10⁶ J. One kilowatt hour is 3.6 × 10⁶ joule, so 5.5 kWh = 5.5 × 3.6 × 10⁶ = 19.8 × 10⁶ joule.

The kilowatt hour is the commercial unit of electrical energy, the unit in which the electricity board bills a house, and it is often called one unit of electricity. It comes from energy = power × time, so one kilowatt of power drawn for one hour means 1000 watt × 3600 second = 3600000 joule. The joule is the SI unit of energy, and one watt is one joule per second.

Option A is wrong because 14.0 × 10⁶ J is about 3.9 kWh. Option C is wrong because 14.4 × 10⁸ J would be 400 kWh, a hundred times too large. Option D is wrong because 14.4 × 10⁵ J is only 0.4 kWh.

Exam tip: 1 kWh = 3.6 × 10⁶ J = one unit of electricity; multiply the number of units by 3.6 million to get joule.

The correct answer is A, Azerbaijan. The manat is the currency of Azerbaijan, a country of the Caucasus whose capital is Baku on the shore of the Caspian Sea. The name comes from the Russian word moneta, meaning coin, and Turkmenistan calls its currency the manat too, so the two countries share the name. Azerbaijan's oil and gas wealth keeps Baku in the news, and the country is a member of the Commonwealth of Independent States. B is wrong because the currency of Armenia is the dram. C is wrong because the currency of Albania is the lek. D is wrong because Andorra, a small country between France and Spain, uses the euro and has no currency of its own. Exam tip: manat - Azerbaijan and Turkmenistan; dram - Armenia; lari - Georgia; lek - Albania. When every option starts with the same letter, fix the currency to the country instead of guessing.

The correct answer is C, Euro. The euro is the official currency of the European Union. It came into being as an accounting currency in 1999 and reached people's hands as notes and coins on 1 January 2002. It is managed by the European Central Bank at Frankfurt, its symbol is a crossed E and its code is EUR. Not every member state uses it: the group that does is called the eurozone, while members such as Sweden, Poland and Denmark keep their own currencies. A is wrong because the yen is the currency of Japan. B is wrong because the dollar belongs to the United States and several other countries, none of them the European Union. D is wrong because the pound sterling is the currency of the United Kingdom, which never adopted the euro and left the Union in 2020. Exam tip: euro - European Central Bank at Frankfurt, notes and coins from 1 January 2002, and its users form the eurozone.

The correct answer is C, kinetic energy. At the top the object holds only potential energy; as it falls, that store is steadily converted into kinetic energy, and just as it touches the ground almost all of it is kinetic. Potential energy is mgh and kinetic energy is half of mv squared, and in free fall under gravity the sum of the two stays constant, which is the law of conservation of mechanical energy. At the instant of touching the ground the height is zero, so the potential energy is zero, while the speed is greatest, so the kinetic energy is at its maximum. A is wrong because heat appears only after the impact, from friction and deformation, not at the instant of touching. B is wrong because chemical energy is stored in bonds and plays no part in a falling body. D is wrong because potential energy has already dropped to zero at ground level. Exam tip: in a falling body potential energy decreases, kinetic energy increases, and the total mechanical energy stays the same.

The correct answer is A, England and France. The Hundred Years' War was fought between England and France from 1337 to 1453, so it actually ran for 116 years with long truces in between. It began when Edward III of England pressed his claim to the French throne, and behind that lay English lands in France and control of the wool trade of Flanders. England won the famous early battles of Crecy, Poitiers and Agincourt, helped by the longbow, but France recovered after Joan of Arc raised the siege of Orleans in 1429, and by 1453 the English held only Calais. B is wrong because England and Italy fought no such war. C is wrong because England and Germany faced each other in the twentieth-century world wars, not in the fourteenth century. D is wrong because the German-French clash was the Franco-Prussian War of 1870-71, far later and far shorter. Exam tip: Hundred Years' War 1337 to 1453, England against France, turned by Joan of Arc in 1429.

The correct answer is B, National Payments Corporation of India. NPCI is the umbrella organisation that runs India's retail payment and settlement systems. It was set up in 2008 by the Reserve Bank of India and the Indian Banks' Association under the Payment and Settlement Systems Act, 2007, and works as a not-for-profit company owned by banks, with its head office in Mumbai. UPI, RuPay, IMPS, AePS, BHIM, NACH, the National Electronic Toll Collection behind FASTag and the cheque truncation system are all NPCI platforms, which is why nearly every digital retail payment in the country passes through it. A is wrong because the word in the name is Corporation, not Consortium. C is wrong because a piracy council has nothing to do with payments; it is an invented expansion. D is wrong for the same reason, as no National Protection Council runs payment systems. Exam tip: NPCI - set up in 2008 by RBI and IBA, based in Mumbai, and the operator of UPI, RuPay, IMPS and NACH.

The correct answer is D, Fibrous roots. Fibrous roots are the mark of monocotyledonous plants such as wheat, maize, rice and grasses, not of dicots. A dicot seed carries two cotyledons, and its seedling sends down one strong primary root that thickens into a tap root with smaller lateral branches; gram, pea, mustard, neem and mango are familiar examples. Dicot leaves show reticulate or net-like venation, their flowers usually have petals in fours or fives, and their vascular bundles stand in a ring with cambium, so the stem can thicken year after year. A is wrong because the tap root is precisely what a dicot has. B is wrong because reticulate venation is a dicot feature, while monocots show parallel venation. C is wrong because two cotyledons is the very definition of a dicotyledonous plant. Exam tip: dicot - two cotyledons, tap root, reticulate venation; monocot - one cotyledon, fibrous roots, parallel venation.

The correct answer is B, Minsk. Minsk is the capital and largest city of Belarus, a landlocked country of Eastern Europe that shares borders with Russia, Ukraine, Poland, Lithuania and Latvia. Belarus became independent when the Soviet Union broke up in 1991, its currency is the Belarusian rouble, and Minsk also houses the headquarters of the Commonwealth of Independent States. The city gave its name to the Minsk agreements on the conflict in eastern Ukraine, which is why it appears in the news. A is wrong because Baku is the capital of Azerbaijan, a port on the Caspian Sea. C is wrong because Moroni is the capital of Comoros, an island country off the eastern coast of Africa. D is wrong because Brussels is the capital of Belgium and the seat of the European Union and NATO. Exam tip: Belarus - Minsk; Belgium - Brussels; Azerbaijan - Baku; Comoros - Moroni. The similar-sounding country names are the trap here.