RRB JE 2019 Previous Year GK Questions with Answers

The correct answer is C, Respiration in presence of oxygen. Aerobic respiration is the breakdown of glucose in the presence of oxygen, giving carbon dioxide, water and a large amount of energy. It takes place mainly in the mitochondria, which is why they are called the powerhouse of the cell, and one molecule of glucose yields about 38 molecules of ATP. Anaerobic respiration, which happens without oxygen, releases far less energy: yeast converts glucose into ethanol and carbon dioxide, while our muscle cells during hard exercise form lactic acid, the cause of cramps. A is wrong because respiration without molecular oxygen is anaerobic respiration. B is wrong because breathing through the skin, as frogs do, is cutaneous respiration, a route for gas exchange rather than a type of cellular respiration. D is wrong because respiration through gills is branchial respiration, seen in fish. Exam tip: aerobic respiration means with oxygen, 38 ATP, in mitochondria.

The correct answer is A, Nuclear energy. Nuclear power is produced by the fission of uranium and thorium, which are mined ores present in fixed quantities in the Earth's crust, so once used they cannot be replaced within human time. That makes nuclear energy a non-renewable source, in the same class as coal, petroleum and natural gas, even though it releases very little carbon dioxide. A renewable source, by contrast, is one nature refills continuously, such as sunlight, wind, flowing water, biomass and geothermal heat. B is wrong because hydropower uses the water cycle, which the sun keeps running, and is renewable. C is wrong because biomass comes from plants and animal waste that can be grown again. D is wrong because energy from waste uses refuse that households and industry keep producing. Exam tip: renewable means solar, wind, hydro, biomass, geothermal, tidal; non-renewable means coal, oil, gas and nuclear fuels.

The correct answer is B, Alkali metals. Potassium sits in group 1 of the periodic table along with lithium, sodium, rubidium, caesium and francium, and these six are called the alkali metals because their oxides and hydroxides dissolve in water to give strong alkalis. Each has a single electron in its outermost shell, which it loses easily, so they are soft, highly reactive metals that are stored under kerosene and react with water to release hydrogen. Potassium, symbol K from the Latin kalium, burns with a lilac flame. A is wrong because the alkaline earth metals are group 2, such as magnesium and calcium, with two outer electrons. C is wrong because noble gases like helium and argon are group 18 and are almost inert. D is wrong because halogens such as chlorine and iodine are group 17 non-metals. Exam tip: group 1 alkali metals, group 2 alkaline earth metals, group 17 halogens, group 18 noble gases.

The correct answer is A, Vander Waals forces. Graphite is built of flat sheets of carbon atoms arranged in hexagons, and while the atoms inside a sheet are joined by strong covalent bonds, the sheets themselves are held to one another only by weak van der Waals forces. Because these forces are weak, the layers slide over each other easily, which is why graphite feels slippery, is used as a dry lubricant and leaves a mark on paper when used in a pencil. Each carbon in a sheet bonds to three others, so the fourth electron is free to move, making graphite a good conductor of electricity, unlike diamond. B is wrong because coulombic forces act between charged ions, as in sodium chloride. C is wrong because gravitational force between atoms is far too small to matter. D is wrong because no electromagnetic attraction binds the layers. Exam tip: graphite has covalent bonds within layers and van der Waals forces between layers.

The correct answer is C, Double ellipse. In an entity relationship diagram each symbol has a fixed meaning, and an attribute that can hold more than one value for the same entity, such as a person's several phone numbers, is drawn as a double ellipse. The standard set of symbols is worth memorising: a rectangle stands for an entity, a plain ellipse for an ordinary attribute, a diamond for a relationship, a double rectangle for a weak entity, a dashed ellipse for a derived attribute such as age worked out from date of birth, and an underlined attribute for the primary key. A is wrong because a rectangle marks an entity set. B is wrong because a dashed ellipse marks a derived attribute. D is wrong because a diamond marks a relationship between entities. Exam tip: rectangle entity, ellipse attribute, double ellipse multivalued, dashed ellipse derived, diamond relationship, underline key.

The correct answer is B, Turns to steam at high pressure. This describes geothermal energy. Molten rock pushed up from deep inside the Earth collects as hot spots at shallower depths, and groundwater trapped near them is heated until it becomes steam under high pressure. When a pipe is sunk into such a hot spot the trapped steam rushes up, and its pressure is used to turn the turbine of a generator, giving electricity without any fuel. New Zealand, Iceland and the United States use this source on a large scale, and in India the Puga valley in Ladakh and Tattapani in Chhattisgarh are the best known sites. A is wrong because heat cannot turn water to ice. C is wrong because water near hot rocks is heated, not cooled. D is wrong because water merely flowing out would carry no pressure to drive a turbine. Exam tip: geothermal energy is renewable and comes from the Earth's internal heat; Puga valley, Ladakh.

The correct answer is D, Guru Gobind Singh. Guru Gobind Singh, born at Patna in 1666, was the tenth and last human Guru of the Sikhs. In 1699 at Anandpur Sahib he founded the Khalsa, gave the Sikhs the five symbols known as the five Ks and added the names Singh and Kaur. Before his death at Nanded in 1708 he ended the line of living Gurus by declaring the Guru Granth Sahib the eternal Guru. A is wrong because Guru Nanak, born in 1469, was the first Guru and the founder of Sikhism. B is wrong because Guru Arjan Dev was the fifth Guru; he compiled the Adi Granth and built the Harmandir Sahib at Amritsar. C is wrong because Guru Ram Das was the fourth Guru and founded the city of Amritsar. Exam tip: first Nanak, fourth Ram Das, fifth Arjan Dev, ninth Tegh Bahadur, tenth Gobind Singh.

The correct answer is D, Transmission speed. The 56 K rating of a modem means it can transfer data at up to 56 kilobits per second, so the figure describes speed, not size. A modem, short for modulator-demodulator, converts the computer's digital signals into analogue form for a telephone line and converts incoming analogue signals back into digital form. Data transfer speed is measured in bits per second and its multiples, kbps, Mbps and Gbps, and the 56 kbps dial-up modem was the fastest standard for ordinary telephone lines before broadband. A is wrong because the physical size of a modem is not rated in kilobits. B is wrong because memory size is measured in bytes such as MB or GB, not in K of this kind. C is wrong because capacity here is loosely worded; the rating fixes the rate of transfer per second. Exam tip: modem speed is in bits per second; storage is in bytes.

The correct answer is C, White Label ATMs. An ATM set up, owned and operated by a non-bank company registered under the Companies Act is called a white label ATM, because it carries no bank's logo. The Reserve Bank allowed them in 2012 under the Payment and Settlement Systems Act to spread cash access into small towns and villages, and the first one in India was opened by Tata Communications Payment Solutions under the Indicash brand. The cash in the machine and the customer's account still belong to a sponsor bank, while the non-bank operator runs the machine and earns a fee from the banks. A brown label ATM, by contrast, is one whose hardware is owned by a service provider while a bank holds the licence and supplies the cash. A, B and D are wrong because yellow, black and grey label ATMs are not categories the Reserve Bank recognises. Exam tip: white label means non-bank owned; brown label means bank licensed, outsourced hardware.

The correct answer is D, All of the options. In a packet switched network a packet meets four kinds of delay at every router on its path, and transmission, processing and queuing delays are three of them. Processing delay is the time a router takes to read the header and decide the outgoing link. Queuing delay is the time the packet waits in the output buffer while earlier packets are sent, so it grows as traffic grows. Transmission delay is the time needed to push all the bits of the packet onto the link, equal to packet length divided by link bandwidth. The fourth is propagation delay, the time the signal takes to travel the length of the link. A, B and C are each wrong only because they name a single delay, while all three are present together in packet switching. Exam tip: total delay = processing + queuing + transmission + propagation.

The correct answer is B, 1111 0000 1101 0010. The ones complement of a binary number is found by simply inverting every bit, turning each 0 into 1 and each 1 into 0. Taking the given number group by group, 0000 becomes 1111, 1111 becomes 0000, 0010 becomes 1101 and 1101 becomes 0010, which gives 1111 0000 1101 0010. Computers use this idea because subtraction can then be done with addition: the twos complement, used to store negative numbers, is the ones complement plus one. A is wrong because several of its bits are not the inverse of the matching bits. C is wrong because its last eight bits repeat the original number instead of inverting it. D is wrong because its first group should be 1111, not 1001. Exam tip: ones complement means invert every bit; twos complement means invert every bit and add 1.

The correct answer is B, Rod-shaped. Bacteria are grouped by shape, and bacilli are the rod-shaped ones; the Latin word bacillus itself means a small rod or stick. Tuberculosis, tetanus, typhoid and anthrax are all caused by rod-shaped bacteria, and Lactobacillus, the bacterium that curdles milk into curd, belongs to the same group. The other shapes in this classification are cocci, which are spherical, spirilla, which are long and spiral, and vibrio, which are curved like a comma. A is wrong because comma-shaped bacteria are called vibrio, the best known being Vibrio cholerae, which causes cholera. C is wrong because spiral bacteria are spirilla and spirochaetes. D is wrong because spherical bacteria are cocci, such as Streptococcus. Exam tip: cocci are round, bacilli are rods, spirilla are spirals and vibrio are comma-shaped.

The correct answer is C, Odisha. Patachitra is the traditional cloth-scroll painting of Odisha, closely tied to the Jagannath temple at Puri. The word comes from pata, meaning cloth, and chitra, meaning picture. Artists prepare the canvas by pasting layers of cloth with tamarind seed paste, use natural colours from conch shell, lamp black and mineral stones, and paint themes from the lives of Jagannath, Krishna and Radha with bold outlines and decorative floral borders. The village of Raghurajpur in Puri district is its best known centre and Odisha Patachitra carries a Geographical Indication tag. A is wrong because Gujarat is known for Pithora painting and Patola weaving. B is wrong because Tamil Nadu is known for Tanjore painting. D is wrong because Andhra Pradesh is known for Kalamkari and Cherial scrolls. Exam tip: Patachitra with Odisha and Raghurajpur; Madhubani with Bihar; Warli with Maharashtra; Kalamkari with Andhra Pradesh.

The correct answer is C, Vijayalakshmi Pandit. Vijaya Lakshmi Pandit was elected President of the United Nations General Assembly for its eighth session in 1953, becoming the first Indian and the first woman in the world to hold that office. She was the sister of Jawaharlal Nehru, led India's delegation to the United Nations, and later served as ambassador to the Soviet Union, the United States and the United Kingdom, and as Governor of Maharashtra. A is wrong because Sarojini Naidu was the first Indian woman President of the Congress and the first woman Governor of an Indian province, not a United Nations office holder. B is wrong because Indira Gandhi was India's first woman Prime Minister. D is wrong because Annie Besant, an Irish-born theosophist, was Congress President in 1917. Exam tip: Vijaya Lakshmi Pandit, 1953, first woman President of the UN General Assembly; Sarojini Naidu, first woman Governor in India.

The correct answer is D, Pressure. Thrust is the force acting perpendicular to a surface, and the thrust acting on unit area of that surface is called pressure, so pressure = thrust ÷ area. Its SI unit is the pascal, where one pascal is one newton per square metre. Because area sits in the denominator, the same force gives a larger pressure on a smaller area, which is why a sharp knife cuts easily and why a camel's broad feet keep it from sinking into sand. A is wrong because volume is the space an object occupies, measured in cubic metres. B is wrong because surface area is only the area itself, not a force spread over it. C is wrong because density is mass per unit volume, measured in kilograms per cubic metre. Exam tip: pressure = thrust/area in pascal; density = mass/volume in kg per cubic metre; do not mix the two formulas.

The correct answer is A, Golf. The Ryder Cup is a team golf tournament, played between teams representing the United States and Europe. It began in 1927 and is named after Samuel Ryder, the English seed merchant who donated the trophy. The event is held every two years, the venue alternating between American and European courses, and unlike most professional golf it is a match-play team contest in which no prize money is paid to the players. The women's equivalent is the Solheim Cup. B is wrong because table tennis has the Swaythling Cup and the Corbillon Cup. C is wrong because cricket's main trophies are the World Cup, the Ashes and the Ranji Trophy. D is wrong because hockey has the Azlan Shah Cup and, in India, the Dhyan Chand Trophy and the Rangaswamy Cup. Exam tip: link golf with the Ryder Cup, the Solheim Cup, the Walker Cup and the Presidents Cup.

The correct answer is C, 1024 megabytes. Computer storage is counted in powers of two, so each step up the ladder multiplies by 1024, and one gigabyte equals 1024 megabytes. The full ladder that papers test is: 8 bits make 1 byte, 1024 bytes make 1 kilobyte, 1024 kilobytes make 1 megabyte, 1024 megabytes make 1 gigabyte, 1024 gigabytes make 1 terabyte, and 1024 terabytes make 1 petabyte. The figure 1024 appears because it is 2 raised to the power 10, the natural unit for binary addressing. A is wrong because 1391 megabytes is not a power-of-two figure at all. B is wrong because 1024 kilobytes make one megabyte, not one gigabyte. D is wrong because 1150 megabytes is simply a made-up number. Exam tip: learn the chain bit, byte, KB, MB, GB, TB, PB with 1024 at every step, and 8 bits in one byte.

The correct answer is C, 24 Joule. Work done in moving a charge through a potential difference is W = Q × V, so W = 2 × 12 = 24 joule. Potential difference between two points is defined as the work done per unit charge in carrying that charge from one point to the other, that is V = W/Q. Its unit, the volt, is therefore one joule per coulomb, and this work does not depend on the path taken between the two points. Moving 2 coulombs across 12 volts thus needs 24 joules of energy. A is wrong because 6 joule would be the work for only 0.5 coulomb at 12 V. B is wrong because 18 joule does not follow from any pairing of the given values. D is wrong because 12 joule is the work for 1 coulomb, not for 2 coulombs. Exam tip: remember V = W/Q, so W = QV, and 1 volt = 1 joule per coulomb.

The correct answer is D, Shift + Space. Pressing Shift together with the spacebar selects the whole row that holds the active cell, from column A right across to the last column of the grid. The row number on the left turns highlighted, and any formatting, deletion or height change you apply next affects the entire row.

Option A, Ctrl + Shift + Space, selects the whole worksheet, which is the same thing Ctrl + A does when the active cell stands outside a data range. Option B, Ctrl + Home, does not select anything at all; it only moves the cursor back to cell A1 from wherever it happens to be. Option C, Ctrl + Space, is the companion of the right answer and selects the whole column instead of the whole row, which is exactly the swap the paper setter is hoping for. Remember the pair together: Shift for the row, Ctrl for the column.

The correct answer is C, Pitch. Pitch is the characteristic of a sound by which the brain judges it as shrill or flat, and it is decided by the frequency of the wave. A higher frequency is heard as a higher pitch, which is why a woman's voice or a whistle sounds shriller than a drum or a man's voice. The physical quantity is frequency; the sensation produced in the brain is pitch.

Option A, wavelength, is the distance between two successive compressions and is a measurement of the wave in space, not a sensation. Option B, wave velocity, depends on the medium and its temperature and is the same for a shrill and a flat sound in the same air. Option D, oscillation, simply means one complete to and fro vibration; counting oscillations per second gives frequency, but the word itself names no property that the brain interprets.