McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 451. |
Among the following the hardest metal is – |
| A. | Gold |
| B. | Iron |
| C. | Platinum |
| D. | Tungsten |
| Answer» D. Tungsten | |
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Explanation: Titanium is the hardest natural metal in the world. It is very strong, three times the strength of steel and much stronger than gold, silver and platinum and yet is very light weight. Tungsten carbide is the hardest metal alloy on Earth and is scratch proof under normal wear. Tungsten carbide is two times as hard as steel and four times as hard as titanium. |
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| 452. |
Hardest allotrope of carbon is - |
| A. | diamond |
| B. | graphite |
| C. | coke |
| D. | lamp black |
| Answer» A. diamond | |
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Explanation: Diamond is one well known allotrope of carbon. The hardness and high dispersion of light of diamond make it useful for both industrial applications and jewellery. Diamond is the hardest known natural mineral. This makes it an excellent abrasive and makes it hold polish and luster extremely well. |
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| 453. |
The depletion of ozone layer is due to - |
| A. | chloro fluoro carbon |
| B. | carbon dioxide |
| C. | sulphur dioxide |
| D. | ethane |
| Answer» A. chloro fluoro carbon | |
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Explanation: A chlorofluorocarbon (CFC) is an organic compound that contains only carbon, chlorine, hydrogen and fluorine, produced as a volatile derivative of methane and ethane. The manufacture of such compounds has been phased out (and replaced with products such as R-4104 by the Montreal Protocol because they contribute to ozone depletion in the upper atmosphere. |
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| 454. |
Sodium bicarbonate is commercially known as – |
| A. | Washing soda |
| B. | Baking soda |
| C. | Caustic soda |
| D. | Soda lime |
| Answer» B. Baking soda | |
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Explanation: Baking Soda is Sodium bicarbonate or sodium hydrogen carbonate. It is primarily used in cooking (baking), as a leavening agent. It reacts with acidic components in batters, releasing carbon dioxide, which causes expansion of the batter and forms the characteristic texture and grain in pancakes, cakes, quick breads, soda bread, and other baked and fried foods. |
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| 455. |
Coal is formed from – |
| A. | crude oil |
| B. | deposit of animal waste |
| C. | coke |
| D. | compressed and hardened biomass |
| Answer» D. compressed and hardened biomass | |
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Explanation: A fossil fuel, coal forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub- bituminous coal, after that bituminous coal, and lastly anthracite: This involves biological and geological processes that take place over a long period. |
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| 456. |
An example of semiconductor is - |
| A. | German silver |
| B. | Germanium |
| C. | Phosphorous |
| D. | Arsenic |
| Answer» B. Germanium | |
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Explanation: Purified germanium is a semiconductor, with appearance most similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Unlike silicon, it is too reactive to be found naturally on Earth in the free (native) state. |
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| 457. |
Non-stick kitchenwares are coated with |
| A. | PVC |
| B. | Graphite |
| C. | Teflon |
| D. | Silicon |
| Answer» C. Teflon | |
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Explanation: Polytetrafluoroethylene (FYIFE) is a synthetic fluoropolymer of tetrafluoroethylene that finds numerous applications. The best known brand name of FIFE is Teflon. PTFE is used as a non-stick coating for pans and other cookware as it is hydrophobic and possesses fairly high heat resistance. |
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| 458. |
‘Freon' used as refrigerants is chemically known as - |
| A. | chlorinated hydrocarbon |
| B. | fluorinated hydrocarbon |
| C. | chlorofluoro hydrocarbon |
| D. | fluorinated aromatic compound |
| Answer» C. chlorofluoro hydrocarbon | |
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Explanation: In addition to fluorine and carbon, Freons often contain hydrogen, chlorine, or bromine. Thus, Freons are types of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and related compounds. |
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| 459. |
The material used in the manufacture of lead pencil is – |
| A. | Graphite |
| B. | Lead |
| C. | Carbon |
| D. | Mica |
| Answer» A. Graphite | |
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Explanation: Pencils create marks via physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface. They are noticeably distinct from pens, which dispense liquid or gel ink that stain the light colour of the paper. Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. |
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| 460. |
If all bullets could not be removed from gun shot injury of a man, it may cause poisoning by – |
| A. | Mercury |
| B. | Lead |
| C. | Iron |
| D. | Arsenic |
| Answer» B. Lead | |
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Explanation: Lead is used in building construction, lead-acid batteries, bullets and shot, weights, as part of solders, pewters, fusible alloys, and as a radiation shield. Lead has the highest atomic number of all of the stable elements, although the next higher element, bismuth, has a half-life that is so long (much longer than the age of the universe) that it can be considered stable. Its four stable isotopes have 82 protons, a magic number in the nuclear shell model of atomic nuclei. |
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| 461. |
Nail polish remover contains? |
| A. | Benzene |
| B. | acetic acid |
| C. | acetone |
| D. | petroleum ether |
| Answer» C. acetone | |
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Explanation: Acetone can remove artificial nails made of acrylic or cured gel. A less harsh nail polish remover is ethyl acetate, which often also contains isopropyl alcohol. Ethyl acetate is usually the original solvent for nail polish itself. |
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| 462. |
Which of the following metals is NOT obtained by reduction using carbon? |
| A. | Copper |
| B. | Sodium |
| C. | Iron |
| D. | Zinc |
| Answer» B. Sodium | |
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Explanation: Metals such as zinc, iron and copper are present in ores as their oxides. Each of these oxides is heated with carbon to obtain the metal. |
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| 463. |
One of the following is used to dissolve noble metals. That is – |
| A. | Nitric acid |
| B. | Hydrochloric acid |
| C. | Sulphuric acid |
| D. | Aqua ragia |
| Answer» D. Aqua ragia | |
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Explanation: Aqua regia ("royal water"), aqua aegis ("king's water"), or nitro-hydrochloric acid is a highly corrosive mixture of acids, a fuming yellow or red solution. The mixture is formed by freshly mixing concentrated nitric acid and hydrochloric acid, usually in a volume ratio of 1:3. It was named so because it can dissolve the so-called royal or noble metals, gold and platinum. However, titanium, iridium, ruthenium, tantalum, osmium, rhodium and a few other metals are capable of withstanding its corrosive properties. |
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| 464. |
Water can be separated from alcohol water mixture by – |
| A. | decantation |
| B. | evaporation |
| C. | distillation |
| D. | sublimation |
| Answer» C. distillation | |
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Explanation: Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction. Commercially, distillation has a number of applications. It is used to separate crude oil into more fractions for specific uses such as transport, power generation and heating. Water is distilled to remove impurities, such as salt from seawater. Air is distilled to separate its components— notably oxygen, nitrogen, and argon— for industrial use. |
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| 465. |
'Milk Sugar' is – |
| A. | Lactose |
| B. | Maltose |
| C. | Galactose |
| D. | Sucrose |
| Answer» A. Lactose | |
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Explanation: Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2-8% of milk (by weight), although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from lac or lactis, the Latin word for milk, plus the -ose ending used to name sugars. It has a formula of C12H22O11. Food industry applications, both of pure lactose and lactose- containing dairy by-products, have markedly increased since the 1960s. |
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| 466. |
Which of the following is not a nitrogenous fertilizer? |
| A. | Ammonium sulphate |
| B. | Urea |
| C. | Ammonium nitrate |
| D. | Superphosphate |
| Answer» D. Superphosphate | |
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Explanation: Superphosphate is a common synthetic phosphorus fertilizer. |
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| 467. |
Which of the following is chief source of Naphthalene? |
| A. | Moth balls |
| B. | Moth flakes |
| C. | Tar Camphor |
| D. | Methyl Alcohol |
| Answer» C. Tar Camphor | |
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Explanation: Petroleum-derived naphthalene is usually purer than that derived from coal tar. |
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| 468. |
Which of the following is the petroleum wax? |
| A. | Bees wax |
| B. | Carnauba wax |
| C. | Paraffin wax |
| D. | Jojoba wax |
| Answer» C. Paraffin wax | |
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Explanation: Waxes are a class of chemical compounds that are plastic (malleable) near ambient temperatures. Characteristically, they melt above 45 °C, (113 °F) to give a lowviscosity liquid. Waxes are insoluble in water but soluble in organic, non-polar solvents. All waxes are organic compounds, both synthetic and naturally occurring. |
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| 469. |
Which variety of coal contains recognizable traces of the original plant material? |
| A. | Anthracite |
| B. | Lignite |
| C. | Peat |
| D. | Bitumen |
| Answer» C. Peat | |
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Explanation: Peat contains recognizable traces of the original plant material. Initially the peat is converted into lignite or 'brown coal' - these are coal-types with low organic maturity. In comparison to other coals, lignite is quite soft and its colour can range from dark black to various shades of brown. |
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| 470. |
Sodium calcium silicate is called. |
| A. | Hard glass |
| B. | Borosilicate glass |
| C. | Soft glass |
| D. | Jena glass |
| Answer» C. Soft glass | |
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Explanation: Ordinary glass which is also known as soda glass or soft glass is a mixture of sodium silicate, Calcium silicate, and Silica. |
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| 471. |
A gas used as a disinfectant in drinking water is - |
| A. | Hydrogen |
| B. | Oxygen |
| C. | Fluorine |
| D. | Chlorine |
| Answer» D. Chlorine | |
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Explanation: Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. |
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| 472. |
Who developed atom bomb? |
| A. | Warn& Wan Brown |
| B. | J. Robert Openheimer |
| C. | Edward Taylor |
| D. | Samuel Koehen |
| Answer» B. J. Robert Openheimer | |
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Explanation: J. (Julius) Robert Oppenheimer was born in New York City on April 22, 1904. Under Oppenheimer's guidance, the laboratories at Los Alamos were constructed. There, he brought the best minds in physics to work on the problem of creating an atomic bomb. In the end, he was managing; more than 3,000 people, as well as tackling theoretical and mechanical problems that arose. He is often referred to as the "father" of the atomic bomb. |
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| 473. |
The major harmful gas emitted by automobile vehicle which causes air pollution is – |
| A. | Carbon Monoxide |
| B. | Methane |
| C. | Carbon dioxide |
| D. | Ozone gas |
| Answer» A. Carbon Monoxide | |
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Explanation: Carbon monoxide is the major harmful gas emitted by the automobile vehicles which causes air pollution. Carbon monoxide (CO) - A product of incomplete combustion, carbon monoxide reduces the blood’s ability to carry oxygen; overexposure (carbon monoxide poisoning) may be fatal. Carbon Monoxide poisoning is a major killer. |
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| 474. |
Humburger effect is otherwise known as- |
| A. | Sodium pump |
| B. | Anaerobic metabolism |
| C. | Choloride shift |
| D. | Respiratory product |
| Answer» C. Choloride shift | |
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Explanation: Hamburger shift (also known as the Chloride shift) is a process which occurs in the cardiovascular system and refers to the exchange of bicarbonate and chloride across the membrane of red blood cells |
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| 475. |
The purest form of water in nature is – |
| A. | Rain water |
| B. | Lake water |
| C. | River water |
| D. | Sea water |
| Answer» A. Rain water | |
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Explanation: Rainwater is often considered the purest form of water available on the Earth. The evaporation of water by the sun allows the salts and other impurities to be left behind out of the water. However, in reality, rain water is often much less than pure when it reaches the surface of the Earth due to the high pollution of air with toxic gases. |
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| 476. |
The element used for making solar cells is - |
| A. | Magnesium |
| B. | Sodium |
| C. | Calcium |
| D. | Silicon |
| Answer» D. Silicon | |
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Explanation: Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystaijhne silicon, amorphous silicon, cadmium telluride, and copper indium selenideisulfide. |
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| 477. |
What is the number of atoms constituting a molecule known as - |
| A. | Atomic number |
| B. | Isotopes |
| C. | Atomic mass |
| D. | Atomicity |
| Answer» D. Atomicity | |
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Explanation: Atomicity is the total number of atoms present in one molecule of an element. |
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| 478. |
If water smells bad, then that odour can be removed by adding - |
| A. | alum |
| B. | bleach |
| C. | activated carbon |
| D. | deactivated nitrogen |
| Answer» C. activated carbon | |
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Explanation: Adding powdered activated carbon to water or using of granular activated carbon (GAC) in the water filter can remove bad taste and foulodor. |
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| 479. |
Substance used as an anti-freeze in radiators of automobiles is : |
| A. | Methyl alcohol and H2O |
| B. | Methy] alcohol |
| C. | Ethyl alcohol |
| D. | Ethyl alcohol and H2O |
| Answer» A. Methyl alcohol and H2O | |
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Explanation: Methyl alcohol and water are used as an anti-freeze in radiators of automobiles. |
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| 480. |
The function of sedimentation tank in sewage treatment is to: |
| A. | Disinfect the sewage |
| B. | Remove water content |
| C. | Aerate the sewage |
| D. | Remove suspended solids |
| Answer» D. Remove suspended solids | |
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Explanation: The function of sedimentation tank in the sewage treatment is to remove suspended solids. |
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| 481. |
Wich of the following is a method/process of disposing of solid waste which cannot be re-used or recycled? |
| A. | Landfills |
| B. | Incineration |
| C. | Pyrolysis and Gasification |
| D. | An the above |
| Answer» D. An the above | |
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Explanation: Landfills, Incineration, Pyrolysis and Gasification are methods of disposing of solid waste which cannot be reused or recycled. |
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| 482. |
The weight of 6.023 x 1022 atoms of carbon is – |
| A. | 12 gms |
| B. | 120 gms |
| C. | 1.2 gms |
| D. | 0.12 gms |
| Answer» A. 12 gms | |
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Explanation: The number is known as Avogadro 's Number which is the number of atoms in 12g of the isotope carbon-12. carbon atoms weigh = 12 grams. |
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| 483. |
Sulphur dioxide bleaches colouring matter by – |
| A. | Reduction |
| B. | Dehydration |
| C. | Decomposition |
| D. | Oxidation |
| Answer» A. Reduction | |
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Explanation: Sulphur dioxide gas exhibits bleaching properties in presence of moisture. It dissolves in water liberating nascent hydrogen. Nascent hydrogen removes oxygen atoms from the colouring matter (reduces colouring matter) and it loses its colour. |
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| 484. |
Which of the following elements is not radioactive? |
| A. | Radium |
| B. | Plutonium |
| C. | Zirconium |
| D. | Uranium |
| Answer» C. Zirconium | |
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Explanation: Zireonium is a lustrous, grey- white, strong transition metal that resembles titanium. Zirconium is mainly used as a refractory and pacifier, although it is used in small amounts as an alloying agent for its strong resistance to corrosion. |
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| 485. |
KMnO4 can be used as – |
| A. | Insecticide |
| B. | Fertilizer |
| C. | Pesticide |
| D. | Disinfectant |
| Answer» D. Disinfectant | |
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Explanation: Potassium permanganate is an inorganic chemical compound with the formula KMnO4. As an oxidant, potassium permanganate can act as an antiseptic. For example, dilute solutions are used to treat canker sores (ulcers), disinfectant for the hands and treatment for mild pompholyx, dermatitis, and fungal infections of the hands or feet. Potassium permanganate is used extensively in the water treatment industry. |
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| 486. |
A thick paste of cement, sand and water is called – |
| A. | Concrete |
| B. | R.C.C. |
| C. | Mortar |
| D. | Kiln |
| Answer» C. Mortar | |
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Explanation: Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. Modern mortars are typically made from a mixture of sand, a binder such as cement or lime, and water |
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| 487. |
Which one of the following metals pollutes the air of a city having large number of automobiles? |
| A. | Cadmium |
| B. | Chromium |
| C. | Lead |
| D. | Copper |
| Answer» C. Lead | |
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Explanation: The history of car pollution has been one of air and water contamination followed by regulated improvement. Cars and trucks cause a lot of air the pollution in the world today, and contribute a lot to the most common and dangerous air pollutants. About 2.3 million tons of lead in lead acid (PbA) batteries is on the road now. Over 1 million tons of lead is used in making new batteries each year. In the past, motor vehicles were the biggest source of lead. But since leaded gasoline has been phased out, lead emissions have decreased by about 98 percent. |
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| 488. |
`Milk of Magnesia' is a suspension of – |
| A. | magnesium sulphate |
| B. | magnesium carbonate |
| C. | magnesium hydroxide |
| D. | magnesium chloride |
| Answer» C. magnesium hydroxide | |
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Explanation: Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water. it is often called milk of magnesia because of its milk-like appearance. |
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| 489. |
Pollutant from motor car exhaust that causes mental disease is – |
| A. | Lead |
| B. | NO2 |
| C. | SO2 |
| D. | Hg |
| Answer» A. Lead | |
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Explanation: Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems. It interferes with the development of the nervous system, and is therefore particularly toxic to children. |
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| 490. |
The total energy of revolving electron in an atom – |
| A. | cannot be negative |
| B. | can have any value above zero |
| C. | can never be positive |
| D. | will always be positive |
| Answer» C. can never be positive | |
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Explanation: The total energy of a revolving electron in any orbit is the sum of its kinetic and potential energies. Energy of an electron at infinite distance from the nucleus is zero. As an electron approaches the nucleus, the electron attraction increaes and the energy of electron decreases and thus becomes negative. Thus, it can never be positive. |
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| 491. |
The chief source for the production of nitrogeneous fertilizers is : |
| A. | Ammonia |
| B. | Nitric acid |
| C. | Nitrogen |
| D. | Nitrogen dioxide |
| Answer» A. Ammonia | |
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Explanation: Nitrogen fertilizers are often made using the Haber-Bosch process which uses natural gas for the hydrogen and nitrogen gas from the air at an elevated temperature and pressure in the presence of a catalyst to form ammonia as the end product. This ammonia is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea. |
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| 492. |
Zn + 2 HCl = H2 + ZnCl, is an example of which type of reaction? |
| A. | Double displacement reaction |
| B. | Combination reaction |
| C. | Single displacement reaction |
| D. | Decomposition reaction |
| Answer» C. Single displacement reaction | |
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Explanation: This reaction is an example of single displacement reaction. In Substitution or Single Replacement Reactions, a single free element replaces or is substituted for one of the elements in a compound. |
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| 493. |
Which of the following is not a natural polymer? |
| A. | Wool |
| B. | Silk |
| C. | Cotton |
| D. | Teflon |
| Answer» D. Teflon | |
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Explanation: Natural polymers occur in nature and can be extracted. They are often water- based. Examples of naturally occurring polymers are silk, wool, DNA, cellulose, cotton and proteins. |
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| 494. |
Vulcanized rubber contains sulphur – |
| A. | 2% |
| B. | 3-5% |
| C. | 7-9% |
| D. | I 0- 5% |
| Answer» B. 3-5% | |
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Explanation: A vulcanized flexible tyre rubber contains about 3 -5% of sulphur whereas hard rubber (ebonite) contains about 32% of sulphur. The stiffness of vulcanized rubber depends on the amount of sulphur added. |
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| 495. |
Which of the following is a metallic ore? |
| A. | Mica |
| B. | Quartz |
| C. | Feldspar |
| D. | Galena |
| Answer» D. Galena | |
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Explanation: Galena is the most abundant lead mineral. It is a metallic, lead-gray mineral with cubic cleavage and a distinctly high density. It belongs to the octahedral sulfide group of minerals with metal ions in octahedral positions. |
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| 496. |
The first organic compound synthesized in the laboratory was - |
| A. | Urea |
| B. | Uric acid |
| C. | Lactic acid |
| D. | Glucose |
| Answer» A. Urea | |
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Explanation: In 1828, German chemist Friedrish Wohler synthesized first organic compound, urea in the laboratory by heating ammonium cyanate (an inorganic compound). |
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| 497. |
The green colour seen in firework displays is due to the chloride salt of– |
| A. | Sodium |
| B. | Strontium |
| C. | Barium |
| D. | Calcium |
| Answer» C. Barium | |
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Explanation: The red, orange, yellow, green, blue and purple colors exploding in the night skyduring a pyrotechnic festival are created by the use of metal salts. Barium chloride provides green colour to firework displays. Metal salts that are commonly used in fire-work displays include: strontium carbonate (red), calcium chloride (orange), sodium nitrate (yellow), barium chloride (green fireworks) and copper chloride (blue fireworks). |
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| 498. |
The radiation that can penetrate deepest in our body – |
| A. | UV-radiation |
| B. | Alpha-particles |
| C. | a-particles |
| D. | Gamma-particles |
| Answer» D. Gamma-particles | |
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Explanation: The ability of radioactivity to pass through materials is called its penetrating ability. Penetrating ability depends on the size of the radioactive particle. Alpha particles are the biggest, beta particles are very much smaller and gamma rays have no mass. |
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| 499. |
Which adioactive pollutant has recently drawn the attention of the public due to its occurrence in the building materials? |
| A. | Radium |
| B. | Radon |
| C. | Thorium |
| D. | Rlutonium |
| Answer» C. Thorium | |
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Explanation: Thorium, a naturally occurring radioactive element, four times more abundant than uranium in the earth's crust. |
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| 500. |
Chemical properties of isotopes – |
| A. | must be same |
| B. | must be different |
| C. | need not be same |
| D. | need not be different |
| Answer» A. must be same | |
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Explanation: Isotopes of an element have similar chemical properties as they have the same number of electrons as an atom of that element. The electron arrangement is the same owing to same chemical properties. However, they have different numbers of neutrons, which |
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