McqMate
| 901. |
lodex, a pain relief balm, has the smell of . |
| A. | Methyl salicylate |
| B. | Ethyl salicylate |
| C. | Propyl salicylate |
| D. | Butyl salicylate |
| Answer» A. Methyl salicylate | |
|
Explanation: Iodex has the characteristic odour of Methyl salicylate, an organic ester naturally produced by many species of plants, particularly wintergreens. It is used in high concentrations as a rubefacient and analgesic in deep heating liniments to treat joint and muscular pain. |
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| 902. |
A complex compound in which the oxidation number of a metal is zero is - |
| A. | K4 [Fe (CN)6] |
| B. | K3 [Fe (CN)6] |
| C. | [Ni (CO)4] |
| D. | [Pl (NH3)4]Cl2 |
| Answer» C. [Ni (CO)4] | |
|
Explanation: 0 |
|
| 903. |
What is a Bakelite? |
| A. | Solution |
| B. | Acid |
| C. | Base |
| D. | Polymer |
| Answer» D. Polymer | |
|
Explanation: Bakelite is the commercial name for the polymer obtained by the polymerization of phenol and formaldehyde. It is an early plastic. Plastic (from the Greek "plastikos," meaning moldable) is the popular term for a variety of synthetic, or manmade, polymers. Bakelite was developed by the BelgianAmerican chemist Leo Baekeland in New York in 1907. |
|
| 904. |
What do you understand by the term Espuma? |
| A. | Foam |
| B. | Soap |
| C. | Salt |
| D. | Calcium |
| Answer» A. Foam | |
|
Explanation: Espuma is a Spanish term for froth or foam, and one that is created specifically with the use of a siphon bottle. Espuma is created mainly with liquid that has air incorporated in it to create froth. This is a specific term, since culinary foams may be attained through other means. |
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| 905. |
The element used for vulcanizing rubber is - |
| A. | Sulphur |
| B. | Bromine |
| C. | Silicon |
| D. | Phosphorus |
| Answer» A. Sulphur | |
|
Explanation: The vulcanization of neoprene or polychloroprene rubber (CR rubber) is carried out using metal oxides (specifically MgO and ZnO, sometimes Pb3O4) rather than sulfur compounds which are presently used with many natural and synthetic rubbers. |
|
| 906. |
Heavy metals got their name because compared to other atoms they have - |
| A. | Higher densities |
| B. | Higher atomic masses |
| C. | Higher atomic numbers |
| D. | Higher atomic radii |
| Answer» B. Higher atomic masses | |
|
Explanation: Arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and selenium are some of the metals called 'heavy' because of their high relative atomic mass. They persist in nature and can cause damage or death in animals, humans, and plants even at very low concentrations. |
|
| 907. |
Concentration of a material which is lethal to 50% animal is called– |
| A. | LD50 |
| B. | LC50 |
| C. | NOAEL |
| D. | ADI |
| Answer» A. LD50 | |
|
Explanation: LD50 (Lethal Dose 50) is the amount of a solid or liquid material that it takes to kill 50% of test animals (for example, mice or rats) in one dose. LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material. LC50 is the concentration of a material in air that will kill 50% of the test subjects when administered as a single exposure. |
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| 908. |
Muddy water is treated with alum in purification process, it is termed as : |
| A. | emulsification |
| B. | absorption |
| C. | adsorption |
| D. | coagulation |
| Answer» D. coagulation | |
|
Explanation: Natural and wastewater contain small particulates that are suspended in waterforming a colloid. These particles carry the same charges, and repulsion prevents them from combining into larger particulates to settle. |
|
| 909. |
‘Plaster of paris’ chemically known as |
| A. | Sodium Aluminate |
| B. | Calcium sulphate |
| C. | Spdium bicarbonate |
| D. | Sodium acetate |
| Answer» B. Calcium sulphate | |
|
Explanation: Calcium sulphate is a calcium salt that is used for a variety of purposes. It exists in various forms and states of hydration. |
|
| 910. |
Which mineral is the ore of aluminium? |
| A. | Haematite |
| B. | Bauxite |
| C. | Magnetite |
| D. | Siderite |
| Answer» B. Bauxite | |
|
Explanation: Bauxite is an aluminium ore and is the main source of aluminium. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis. |
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| 911. |
Which gas is used for converting vegetable oils into saturated fats? |
| A. | H2 |
| B. | O2 |
| C. | Cl2 |
| D. | SO2 |
| Answer» A. H2 | |
|
Explanation: Hydrogenation - to treat with hydrogen - is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst. The largest scale application of hydrogenation is for the processing of vegetable oils (fats to give margarine and related spreads and shortenings). Typical vegetable oils are derived from polyunsaturated fatty acids (containing more than one carbon-carbon double bonds). |
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| 912. |
An electric iron has a heating element made of – |
| A. | Copper |
| B. | Tungsten |
| C. | Nichrome |
| D. | Zinc |
| Answer» C. Nichrome | |
|
Explanation: Nichrome is used in electric iron because it has high resistance and it is stable in air when hot. Nichrome wire forms a protective layer ofchromium oxide. Chemically it is quite stable and does not combine with other atmospheric gases even in high temperature. |
|
| 913. |
The process of covering water pipes made of Iron with Zinc layer to prevent corrosion is called – |
| A. | Zinc plating |
| B. | Alloy formation |
| C. | Vulcanization |
| D. | Galvanization |
| Answer» D. Galvanization | |
|
Explanation: Galvanization is the process of applying a protective zinc coating to steel or iron, in order to prevent rusting. |
|
| 914. |
Which of the following is most important for absorption of heat radiated from the Sun as well as from the Earth? |
| A. | Carbon dioxide |
| B. | Oxygen |
| C. | Carbon monoxide |
| D. | Nitrogen |
| Answer» A. Carbon dioxide | |
|
Explanation: Carbon dioxide is a green house gas that absorbs heat radiated from the Sun as well as re-radiated heat from the Earth's surface. |
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| 915. |
Philosopher’s wool is chemically - |
| A. | Aluminium oxide |
| B. | Magnesium oxide |
| C. | Zinc oxide |
| D. | Calcium oxide |
| Answer» C. Zinc oxide | |
|
Explanation: Philosopher's Wool is chemically zinc oxide. |
|
| 916. |
Charcoal is used in water treatment as a/an - |
| A. | absorbent |
| B. | coagulant |
| C. | solvent |
| D. | adsorbent |
| Answer» D. adsorbent | |
|
Explanation: Charcoal is used in water treatment as adsorbent. |
|
| 917. |
The chemical used for cloud seeding for artificial rains is - |
| A. | Silver Nitrate |
| B. | Potassium Bromide |
| C. | Silver Iodide |
| D. | Potassium Nitrate |
| Answer» C. Silver Iodide | |
|
Explanation: The chemical used for cloud seeding for artificial rains is silver iodide. |
|
| 918. |
Which among the following is liquid non-metal? |
| A. | Mercury |
| B. | Bromine |
| C. | Water |
| D. | Alcohol |
| Answer» B. Bromine | |
|
Explanation: Bromine, a non-metal of halogen group, is found in liquid state. Mercury is a metal. Water and alcohol are compounds |
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| 919. |
The percentage of oxygen in air is approximately – |
| A. | 100% |
| B. | 1% |
| C. | 78% |
| D. | 21% |
| Answer» D. 21% | |
|
Explanation: Composition of air Nitrogen : 78.08 percent Oxygen : 20.94 percent Argon : 0.93 percent Carbondioxdide : 0.03 percent Neon : 0.0018 percent Helium 0.0005 percent Ozone : 0.00006 percent Hydrogen : 0.00005 percent |
|
| 920. |
What is the second largest cornponent in milk? |
| A. | Fat |
| B. | Minerals |
| C. | Water |
| D. | Sugar |
| Answer» A. Fat | |
|
Explanation: Components of Milk : Water (87 percent), Carbohydrate (4.9 percent), Fat. (3.4 percent), Protein (3.3 percent), and so on |
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| 921. |
Which of the following is NOT a primary green house gas in the earth's atmosphere? |
| A. | Methane |
| B. | Ozone |
| C. | Nitrous oxide |
| D. | Hydrogen |
| Answer» D. Hydrogen | |
|
Explanation: Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth. |
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| 922. |
The presence of Cobalt in Vitamin B12 was established for the first time by – |
| A. | Hydrolysis test |
| B. | Spectroscopy |
| C. | Borax-Bead test |
| D. | Sodium Nitroprusside test |
| Answer» B. Spectroscopy | |
|
Explanation: Atomic absorption spectroscopy is an analytical chemistry technique used for determining concentration of particular metal element and is widely used in pharmaceutics. It was used for the determination of cobalt in Vitamin B12. |
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| 923. |
Coating of solid waste with impervious material is known as – |
| A. | Encapsulation |
| B. | Chemical fixation |
| C. | Landfill |
| D. | Capping |
| Answer» A. Encapsulation | |
|
Explanation: Containment of toxic or hazardous constituents in industrial solid wastes is currently being accomplished using: (i) coating grains of waste material with an inert and non-reactive impervious material (microencapsulation), and (ii) coating blocks of waste material with an inert, non-reactive impervious material (macroencapsulation). |
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| 924. |
Sweat contains water and . |
| A. | Citric acid |
| B. | Lactic acid |
| C. | Salt |
| D. | Vinegar |
| Answer» C. Salt | |
|
Explanation: Sweat contains mainly water. It also contains minerals, lactate, and urea. It also contains a smaller amount of sodium chloride (main component of ordinary table salt). |
|
| 925. |
How many bones are there in a newly born infant? |
| A. | 206 |
| B. | 230 |
| C. | 280 |
| D. | 300 |
| Answer» D. 300 | |
|
Explanation: At birth, there are over 270 bones in an infant body. But many of these fuse together as the child grows, leaving a total of 206 separate bones in a typical adult. |
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| 926. |
White phosphorus is generally kept under – |
| A. | Alcohol |
| B. | Water |
| C. | Glycerine |
| D. | Kerosene oil |
| Answer» B. Water | |
|
Explanation: White phosphorous is kept under water because it reacts with oxygen but not water. Besides, it is insoluble in water. It presents a significant fire hazard due to its extreme reactivity with atmospheric oxygen. |
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| 927. |
Which of the following acts as a resistance against disease in the body? |
| A. | Carbohydrates |
| B. | Red corpuscles |
| C. | Vitamins |
| D. | White corpuscles |
| Answer» D. White corpuscles | |
|
Explanation: White corpuscles or the White blood cells (WBCs), also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. |
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| 928. |
Which one of the following is the softest |
| A. | sodium |
| B. | iron |
| C. | aluminium |
| D. | lithium |
| Answer» A. sodium | |
|
Explanation: lightest-lithium, heaviest- osmium, hardest-tungsten, soft metal- sodium. |
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| 929. |
Brass contains – |
| A. | Copper and Zinc |
| B. | Copper and Tin |
| C. | Copper and Silver |
| D. | Copper and Nickel |
| Answer» A. Copper and Zinc | |
|
Explanation: Brass is an alloy made of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. By comparison, bronze is principally an alloy of copper and tin. |
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| 930. |
Which is the purest commercial form of iron? |
| A. | Pig iron |
| B. | Steel |
| C. | Stainless steel |
| D. | Wrought iron |
| Answer» D. Wrought iron | |
|
Explanation: Wrought iron or malleable iron is the purest form of commercial iron as it containsthe lowest percentage of carbon (0.12-0.25%) and impurities of S, P, Mn and Si in minute amount (about 0.3%). It is made by melting cast iron with scrap iron in a reverberatory furnace lined with Fe203 which oxidizes C, Si, P, etc, most of which are then removed by rolling. |
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| 931. |
Which of the following particles has the dual nature of particle-wave? |
| A. | Electron |
| B. | Meson |
| C. | Proton |
| D. | Neutron |
| Answer» A. Electron | |
|
Explanation: 0 |
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| 932. |
Ultra purification of a metal is done by |
| A. | slugging |
| B. | zone melting |
| C. | smelting |
| D. | leaching |
| Answer» B. zone melting | |
|
Explanation: When metals are required in a ultra pure state, the zone refining method is used. The principleemployed states that the impurities, which lower the melting point of a metal remain preferentially dissolved in the liquid phase and purer metal will emerge in the solid phase. |
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| 933. |
An antiknock for petrol is - |
| A. | sodium hydroxide |
| B. | ethanol |
| C. | sodium benzoate |
| D. | lead tetraethyl |
| Answer» D. lead tetraethyl | |
|
Explanation: The organic compound that is used as an antiknock agent in petroleum is tetraethyl lead. This is a lead based organic compound. |
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| 934. |
The ratio of Pure gold and 18 carot gold is – |
| A. | 60% |
| B. | 75% |
| C. | 80% |
| D. | 100% |
| Answer» B. 75% | |
|
Explanation: 24-karat gold is pure (while 100% purity is unattainable, this designation is permitted in commerce for 99.95% purity), 18- karat gold is 18 parts gold, 6 parts another metal (forming an alloy with 75% gold). |
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| 935. |
Limestone is a raw material used by which industry? |
| A. | Aluminium |
| B. | Fertilizers |
| C. | Cement |
| D. | Petrochemicals |
| Answer» C. Cement | |
|
Explanation: Limestone is used as a raw- material for the manufacture of quicklime (calcium oxide), slaked lime (calcium hydroxide), cement and mortar. Clay and shale are also used as raw materials for the production of cement. |
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| 936. |
Atomic number of an atom gives the number of which of the following? |
| A. | electrons |
| B. | protons |
| C. | neutrons |
| D. | neutrons and protons |
| Answer» B. protons | |
|
Explanation: Atomic number of a chemical element is the number of protons found in the nucleus of an atom of that element, and therefore identical to the charge number of the nucleus. It determines the place of an element in the periodic table. In an uncharged atom, the atomic number is also equal to the number of electrons. |
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| 937. |
Which one of the following metals does not react with water to produce Hydrogen? |
| A. | Cadmium |
| B. | Lithium |
| C. | Potassium |
| D. | Sodium |
| Answer» A. Cadmium | |
|
Explanation: A cadmium metal does not react with water to produce Hydrogen. |
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| 938. |
Which of the following is not an ore of magnesium? |
| A. | Carnallite |
| B. | Dolomite |
| C. | Calamine |
| D. | Sea water |
| Answer» C. Calamine | |
|
Explanation: 0 |
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| 939. |
Which of the following is usually not an air-pollutant? |
| A. | Hydrocarbons |
| B. | Sulphur dioxide |
| C. | Carbon dioxide |
| D. | Nitrous oxide |
| Answer» D. Nitrous oxide | |
|
Explanation: The six air pollutants are carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide. The combustion of gasoline and other hydrocarbon fuels in automobiles, trucks, and jet airplanes produces several primary air pollutants. Nitrous oxide (N2O), commonly known as laughing gas, is used in surgery and dentistry for its an-aesthetic and analgesic effects. |
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| 940. |
Which of the following fuels causes minimum environmental pollution? |
| A. | Diesel |
| B. | Kerosene |
| C. | Hydrogen |
| D. | Coal |
| Answer» C. Hydrogen | |
|
Explanation: Coal, diesel and kerosene are examples of fossil fuels that contribute to pollution. In contrast, hydrogen burns in air, it produces nothing but water vapor and energy. It is considered as totally clean and nonpolluting source of energy. |
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| 941. |
The compound used in prickly-heat powder to prevent excessive sweating is – |
| A. | Boric acid |
| B. | Phosphoric acid |
| C. | Carbonic acid |
| D. | Sulphonic acid |
| Answer» A. Boric acid | |
|
Explanation: Boric acid (H3BO3), also called hydrogen borate, boracie acid, orthoboric acid and acidum boricum, is used in prickly heat powders to prevent excessive sweating. Boric acid is also used as an antiseptic for minor burns or cuts and is sometimes used in dressings or salves. As an antibacterial compound, boric acid can also be used for acne treatment. |
|
| 942. |
The colour of Emerald is - |
| A. | Violet |
| B. | Yellow |
| C. | Deep Green |
| D. | Prussian Blue |
| Answer» C. Deep Green | |
|
Explanation: The most desirable emerald colors are bluish green to pure green, with vivid color saturation and tone that's not too dark. The most-prized emeralds are highly transparent. Their color is evenly distributed, with no eye- visible colorzoning. |
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| 943. |
The oxygen liberated during Photosynthes is comes from - |
| A. | Water |
| B. | Carbon dioxide |
| C. | Glucose |
| D. | Chlorophyll |
| Answer» A. Water | |
|
Explanation: The oxygen produced during photosynthesis comes from water. The electrons excited by light in the chlorophyll molecule are replaced by electrons produced from the oxidation of water into oxygen. |
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| 944. |
Permanent hardness of water, due to sulphates of the metal, can be destroyed by the use of |
| A. | Nitrates |
| B. | Zeolites |
| C. | Sulphonates |
| D. | None of these |
| Answer» B. Zeolites | |
|
Explanation: Zeolites are crystalline solids structures made of silicon, aluminum and oxygen that form a framework with cavities and channels inside where cations, water and/or small molecules may reside. |
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| 945. |
Adding which substance gives blue colour to glass? |
| A. | Manganese oxide |
| B. | Cobalt oxide |
| C. | Chromium oxide |
| D. | Iron oxide |
| Answer» B. Cobalt oxide | |
|
Explanation: Cobalt is the strongest of the coloring oxides, giving a range of blues in most glasses. It is such a powerful colorant that only a few parts per million is needed to produce a light blue color such as the shade used for certain bottled waters. |
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| 946. |
The antiparticle of an electron is – |
| A. | Positron |
| B. | Proton |
| C. | Alpha particles |
| D. | Beta particles |
| Answer» A. Positron | |
|
Explanation: Corresponding to most kings of particles, there is an associated antiparticle with the same mass and opposite charge (including electric charge). The antiparticle of the electron is the positron (antielectron), which has positive charge and is produced naturally in certain types of radioactive decay. The opposite is also true: the antiparticle of the positron is the electron. |
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| 947. |
Vinegar is . |
| A. | diluted acetic acid |
| B. | glacial acetic acid |
| C. | glacial formic acid |
| D. | diluted formic acid |
| Answer» A. diluted acetic acid | |
|
Explanation: Vinegar is mostly dilute acetic acid, often produced by fermentation and subsequent oxidation of ethanol. It is roughly 3- 9% acetic acid by volume, making acetic acid the main component of vinegar apart from water. |
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| 948. |
What is the product formed when sodium bicarbonate is heated strongly? |
| A. | Sodium Carbonate |
| B. | Sodium Hydroxide |
| C. | Sodium Peroxide |
| D. | Sodium Monoxide |
| Answer» A. Sodium Carbonate | |
|
Explanation: When sodium bicarbonate is strongly heated, it decomposes into sodium carbonate, water vapor, and carbon dioxide. Solid sodium carbonate is a white powder and is used in cooking under the name 'baking powder'; sodium bicarbonate is used in baking under the name 'baking soda'. |
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| 949. |
The most electronegative element among the following is - |
| A. | sodium |
| B. | bromine |
| C. | fluorine |
| D. | oxygen |
| Answer» C. fluorine | |
|
Explanation: Fluorine is the most electronegative element, while francium is one of the least electronegative. |
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| 950. |
Atomic size refers to the of an atom. |
| A. | Radius |
| B. | Circumference |
| C. | Diameter |
| D. | Centre |
| Answer» A. Radius | |
|
Explanation: The term atomic size refers to the radius of an atom. The atomic size may be visualized as the distance between the centre of the nucleus and the outermost shell of an isolated atom. |
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| 951. |
Which is the highest quality of hard coal? |
| A. | Anthracite |
| B. | Bituminous |
| C. | Lignite |
| D. | Peat |
| Answer» A. Anthracite | |
|
Explanation: Anthracite is the highest rank of coal. It is the most metamorphosed type of coal, in which the carbon content is between 92.1% and 98%. Anthracite coal generally has the highest heating value per ton on a mineral- matter-free basis. Anthracite is often referred to as hard coal. |
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| 952. |
Which of the following is not a commercial source of energy? |
| A. | Coal |
| B. | Petroleum |
| C. | Natural Gas |
| D. | Firewood |
| Answer» D. Firewood | |
|
Explanation: Firewood, agricultural waste (straw, etc.) and animals waste (cowdung) are the important components of non-commercial energy. It is generally used in the rural area for domestic purposes— mainly cooking. Coal, petroleum products, natural gas and, electricity are the important components of commercial energy. |
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| 953. |
Which one of the following substances does not have a melting point? |
| A. | Bromine |
| B. | Sodium chloride |
| C. | Mercury |
| D. | Glass |
| Answer» C. Mercury | |
|
Explanation: The boiling point is the temperature at which a material changes from a liquid to a gas (boils) while the melting point is the temperature at which a material changes from a solid to a liquid (melts). |
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| 954. |
Which one of the following metals occurs in nature in free state? |
| A. | Gold |
| B. | Sodium |
| C. | Aluminium |
| D. | Copper |
| Answer» A. Gold | |
|
Explanation: Gold is found on every continent on Earth, except Antarctica. The largest amounts of gold on Earth are found in the oceans - but it is not yet feasible to extract gold from seawater. |
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| 955. |
The soft silvery metalic element which ionizes easily when heated or exposed to light and is present in atomic clocks is – |
| A. | Cerium |
| B. | Cesium |
| C. | Calcium |
| D. | Californium |
| Answer» B. Cesium | |
|
Explanation: 1967, based on Einstein defining the speed of light as the most constant dimension in the universe, the International System of Units isolated two specific wave counts from an emission spectrum of caesium133 to codefine the second and the meter. Since then, caesium has been widely used in highly accurate atomic clocks. Among alkali metals, cesium has lowest ionization energy and hence it can show photoelectric effect to the maximum extent. |
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| 956. |
Catalytic converters are generally made from |
| A. | Alkaline metals |
| B. | Hydrogen |
| C. | Transition metals |
| D. | Carbon |
| Answer» C. Transition metals | |
|
Explanation: Transition metals are used directly as catalysts in the anti-pollution catalytic converters in car exhausts. For example, expensive transition metals such as Platinum and rhodium are used in the catalytic converters in car exhausts to reduce the emission of carbon monoxide and nitrogen monoxide, which are converted to the non-polluting gases nitrogen and carbon dioxide. |
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| 957. |
In galvanization, iron is coated with – |
| A. | Copper |
| B. | Zinc |
| C. | Tin |
| D. | Nickel |
| Answer» B. Zinc | |
|
Explanation: Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanization, in which parts are submerged in a bath of molten zinc. |
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| 958. |
Which one of the folling is also khow as solution? |
| A. | Acompound |
| B. | Ahomogeneous mixture |
| C. | A heterogeneous mixture |
| D. | A suspension |
| Answer» B. Ahomogeneous mixture | |
|
Explanation: In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solution more or less takes on the characteristics of the solvent including its phase. |
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| 959. |
Which of the following is very reactive and kept in kerosene? |
| A. | Sodium |
| B. | Potassium |
| C. | Iodine |
| D. | Bromine |
| Answer» A. Sodium | |
|
Explanation: Sodium is a very reactive metal. It reacts vigorously with oxygen and water. A lot of heat is generated in this process. Therefore, it is stored in kerosene to avoid contacts between either atmospheric oxygen or water. |
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| 960. |
Which one of the following is known as the ‘brown coal’? |
| A. | Anthracite |
| B. | Bituminous |
| C. | Coke |
| D. | Lignite |
| Answer» D. Lignite | |
|
Explanation: Lignite, often referred to as brown coal, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal. It has a carbon content of around 2530%. |
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| 961. |
The chief source of naphthalene is - |
| A. | Coal-tar |
| B. | Diesel |
| C. | Charcoal |
| D. | Camphor |
| Answer» A. Coal-tar | |
|
Explanation: Naphthalene is derived from a kind of naphtha which is a broad term encompassing any volatile, flammable liquid hydrocarbon mixture, including coal tar. |
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| 962. |
This substance is commonly known as alcohol and is also used in medicines such as tincture iodine, cough syrups, and many tonics. This is - |
| A. | Propanol |
| B. | Butane |
| C. | Ethanol |
| D. | Methanol |
| Answer» C. Ethanol | |
|
Explanation: Ethanol is commonly called alcohol and is the active ingredient of all alcoholic drinks. Also, it is a good solvent and is used in medicines such as tincture iodine, cough syrups, and many tonics. |
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| 963. |
Enzymes are - |
| A. | Steroids |
| B. | Carbohydrates |
| C. | Proteins |
| D. | Lipids |
| Answer» C. Proteins | |
|
Explanation: Enzymes are protein molecules in cells which work as catalysts. Most enzymes are proteins, although a few are catalytic RNA molecules; the latter are called ribozymes. |
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| 964. |
Sulphuric acid is – |
| A. | monobasic |
| B. | dibasic |
| C. | tribasic |
| D. | tetrabasic |
| Answer» B. dibasic | |
|
Explanation: An example of a dibasic acid is sulphuric acid H2SO4. Dibasic acids yield two free hydrogen ions in solution for each molecule of acid ionized. |
|
| 965. |
Which of the following metals can deposit copper from copper sulphate solution? |
| A. | platinum |
| B. | Mercury |
| C. | Iron |
| D. | Gold |
| Answer» C. Iron | |
|
Explanation: The iron displaces copper from its salt, to make iron sulfate solution and deposit a thin coating of metallic copper on the surface of the metal. In general, any metal higher than copper in the "electromotive series" will displace copper from copper sulfate solution. |
|
| 966. |
When Arsenic atoms are added Germanium lattice, it becomes a/an - |
| A. | Insulator |
| B. | Superconductor |
| C. | Intrinsic semiconductor |
| D. | Extrinsic semiconductor |
| Answer» D. Extrinsic semiconductor | |
|
Explanation: When a peritavalent (donor) impurity, like arsenic, is added to germanium, it will form covalent bonds with thegermanium atoms, leaving 1 electron relatively free in the crystal structure. Pure germanium may be converted into an N-type semiconductor by "doping" it with any donor impurity having 5 valence electrons in its outer shell. Semiconductors which are doped in this manner - either with N- or P-type impurities - are referred to as EXTRINSIC semiconductors. |
|
| 967. |
Hydrogen bomb is based upon the principle of . |
| A. | Nuclear fission |
| B. | Nuclear fusion |
| C. | Controller nuclear reaction |
| D. | None of these |
| Answer» B. Nuclear fusion | |
|
Explanation: The hydrogen bomb eventually relies upon atomic fusion (adding to the atomic nucleus) to release energy. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei come very close and then collide at a very high speed and join to form a new type of atomic nucleus. |
|
| 968. |
In an acid base reaction which product is produced along with a salt? |
| A. | Hydrogen gas |
| B. | Oxygen gas |
| C. | Carbon dioxide |
| D. | Water |
| Answer» D. Water | |
|
Explanation: When an acid and a base are placed together, they read to neutralize the acid and base properties, producing a salt. The H(+) cation of the acid combines with the OH(-) anion of the base to form water. |
|
| 969. |
The element present in the largest amount in rocks and minerals is - |
| A. | carbon |
| B. | silicon |
| C. | hydrogen |
| D. | aluminium |
| Answer» B. silicon | |
|
Explanation: Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure free element in nature. It is most widely distributed in dusts, sands, planetoids, and planets as various forms of silicon dioxide (silica) or silicates. |
|
| 970. |
Washing soda is - |
| A. | sodium sulphite |
| B. | sodium bicarbonate |
| C. | sodiun carbonate |
| D. | sodium biosulphite |
| Answer» C. sodiun carbonate | |
|
Explanation: Sodium carbonate (also known as washing soda, soda ash and soda crystals, and in the monohydrate form as crystal carbonate), Na2CO3, is the water-soluble sodium salt of carbonic acid. |
|
| 971. |
An element that does not occur in nature but can be produced artificially is – |
| A. | thorium |
| B. | radium |
| C. | plutonium |
| D. | uranium |
| Answer» C. plutonium | |
|
Explanation: 0 |
|
| 972. |
Chloroform can be used as – |
| A. | Analgesic |
| B. | Anaesthetic |
| C. | Antimalarial |
| D. | Antibiotic |
| Answer» B. Anaesthetic | |
|
Explanation: Chloroform can be used as Anaesthetic. Chloroform (CHCl3) on heatingwith silver powder undergoes dehalogenation to form Ethyne. |
|
| 973. |
Gas released during Bhopal tragedy was – |
| A. | Sodium isothiocyanate |
| B. | Potassium isothiocyanate |
| C. | Ethyl isothiocyanate |
| D. | Methyl isothiocyanate |
| Answer» D. Methyl isothiocyanate | |
|
Explanation: Methyl isocyanate is an intermediate chemical in the production of carbamate pesticides. As a highly toxic and irritating material, it is extremely hazardous to human health. It was the principal toxin involved in the Bhopal disaster, which killed nearly 8,000 people initially and approximately 20,000 to 30,000 people in total. |
|
| 974. |
When water itself combines chemically with some element or mineral it is called – |
| A. | Carbonation |
| B. | Desilication |
| C. | Hydration |
| D. | Oxidation |
| Answer» C. Hydration | |
|
Explanation: When water combines chemically with other elements, the process is called hydration. In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl group (-OH) and a hydrogen cation (an acidic proton) are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group. The reaction usually runs in a strong acidic, aqueous solution. Hydration leaves the non-water component intact. |
|
| 975. |
The electronic configuration of an atom having atomic number `20' is – |
| A. | 2, 8, 10 |
| B. | 2, 6, 8, 4 |
| C. | 2, 8, 8, 2 |
| D. | 2, 10, 8 |
| Answer» C. 2, 8, 8, 2 | |
|
Explanation: Electrons occupy shells around the outside of an atom. There can be up to two electrons in the first shell, up to eight in the second and up to eight in the third. A calcium atom (Ca) has electron structure 2,8,8,2. |
|
| 976. |
Which chemical is used to ripen mangoes artificially? |
| A. | Sulphur Dioxide |
| B. | Nitrous Oxide |
| C. | Calcium Carbide |
| D. | Phosphorous |
| Answer» C. Calcium Carbide | |
|
Explanation: The chemical widely used for artificially ripening fruits is calcium carbide (CaC2). It is used to ripen about 80 per cent of mangoes in India. |
|
| 977. |
'Monazite' is an ore of - |
| A. | Sodium |
| B. | Titaniurm |
| C. | Thorium |
| D. | Zirconium |
| Answer» C. Thorium | |
|
Explanation: Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits. India, Madagascar, and South Africa have large deposits of monazite sands. |
|
| 978. |
The luster of a metal is due to - |
| A. | high polishing |
| B. | high density |
| C. | chemical inertness |
| D. | presence of free electrons |
| Answer» D. presence of free electrons | |
|
Explanation: Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin lux, meaning "light", and generally implies radiance, gloss, or brilliance. |
|
| 979. |
The depletion of Ozone layer is mainly due to – |
| A. | Volcanic eruptions |
| B. | Aviation fuels |
| C. | Radioactive rays |
| D. | Chlorofluorocarbons |
| Answer» D. Chlorofluorocarbons | |
|
Explanation: Chlorofluorocarbons (CFCs) and other halogenated ozone depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion. Chloroiluorocarbon (CFC) is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. |
|
| 980. |
Glass is soluble in - |
| A. | H2SO4 |
| B. | HCIO4 |
| C. | HNO3 |
| D. | HF |
| Answer» D. HF | |
|
Explanation: Hydrofluoric acid is a highly corrosive acid, capable of dissolving many materials, especially oxides. Its ability to dissolving lass has been known since the 17th century. It is a solution of hydrogen fluoride in water and is represented by HF. |
|
| 981. |
Acid rain is caused by - |
| A. | SO2 and particulates |
| B. | (2) NO2 and particulates |
| C. | (8) CO2 and CFCs |
| D. | (4) SO2 and NO2 |
| Answer» D. (4) SO2 and NO2 | |
|
Explanation: Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. |
|
| 982. |
What happens in a reduction reaction? |
| A. | addition of Oxygen |
| B. | addition of Nitrogen |
| C. | addition of Hydrogen |
| D. | None of the above |
| Answer» C. addition of Hydrogen | |
|
Explanation: In terms of Oxygen transfer, oxidation is gain of oxygen; reduction is loss of oxygen. However, in terms of hydrogen transfer, oxidation is loss of hydrogen, reduction is gain of hydrogen. |
|
| 983. |
The energy released at the end of digestion is in the form of: |
| A. | electric energy |
| B. | Kinetic energy |
| C. | thermal energy |
| D. | chemical energy |
| Answer» D. chemical energy | |
|
Explanation: Digestion of food involves both physical and chemical processes. During digestion the chemical energy in for released while the molecules of food are broken down into smaller pieces. |
|
| 984. |
The fuel in atomic pile is - |
| A. | carbon |
| B. | sodium |
| C. | petroleum |
| D. | uranium |
| Answer» D. uranium | |
|
Explanation: In the pile, the neutron-producing uranium pellets were separated from one another by graphite blocks. Some of the free neutrons produced by the natural decay of uranium would be absorbed by other uranium atoms, causing nuclear fission of those atoms and the release of additional free neutrons. |
|
| 985. |
The gas used for artificial ripening of green fruit is - |
| A. | Acetylene |
| B. | Ethylene |
| C. | Ethane |
| D. | Carbon dioxide |
| Answer» B. Ethylene | |
|
Explanation: Fruits such as apples and pears emit a greater amount of ethylene gas in fruits, which affects their ripening. |
|
| 986. |
A mixture of water and alcohol can be separated by – |
| A. | Filtration |
| B. | Evaporation |
| C. | Decantation |
| D. | Distillation |
| Answer» D. Distillation | |
|
Explanation: A mixture of water and alcohol is separated by the process of distillation. At 780C, alcohol starts to vaporize. The vapours are condensed in the condenser and alcohol is collected in the receiver. |
|
| 987. |
The inert gas abundantly found in widely distributed is - |
| A. | Xe |
| B. | Kr |
| C. | He |
| D. | Ar |
| Answer» D. Ar | |
|
Explanation: Argon (Ar) is the most prevalent of the noble gases in Earth's crust with the element composing 0.00015% of this crust. |
|
| 988. |
Brine refers to : |
| A. | Salt water |
| B. | Sweet water |
| C. | Pure water |
| D. | Starch water |
| Answer» A. Salt water | |
|
Explanation: Brine is a solution of salt in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% up to about 26%. Other levels of concentration are called in different names. |
|
| 989. |
The Bhopal tragedy was caused by the gas - |
| A. | phosgene |
| B. | carbon monoxide |
| C. | methyl isocyanate |
| D. | chlorine |
| Answer» C. methyl isocyanate | |
|
Explanation: The Bhopal disaster occurred on the night of 2-3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate gas and other chemicals. |
|
| 990. |
Which one of the following contributes largely to the ‘green house effect’? |
| A. | Ozone |
| B. | Carbon monoxide |
| C. | Carbon dioxide |
| D. | Water vapour |
| Answer» D. Water vapour | |
|
Explanation: The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. When these gases are ranked by their direct contribution to the greenhouse effect in percentage terms, the most important are: Water vapour: 36-72 per cent; Carbon dioxide: 9-26 per cent; Methane: 4-9 per cent; and Ozone: 3-7 per cent. |
|
| 991. |
The gas that usually causes explosions in coal mines is - |
| A. | Hydrogen |
| B. | Carbon monoxide |
| C. | Air |
| D. | Methane |
| Answer» D. Methane | |
|
Explanation: Methane is extremely flammable and may form explosive mixtures with air. Methane is violently reactive with oxidizers, halogens, and some halogen-containing compounds. Methane gas explosions are responsible for many deadly mining disasters. |
|
| 992. |
The chemical name for common salt - |
| A. | Sodium chloride |
| B. | Sodium hydroxide |
| C. | Sodium chlorate |
| D. | Potasium chloride |
| Answer» A. Sodium chloride | |
|
Explanation: Sodium chloride is also known common salt is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. |
|
| 993. |
The I.C Chip used in a computer is made up of - |
| A. | Silicon |
| B. | Chromium |
| C. | Gold |
| D. | Lead |
| Answer» A. Silicon | |
|
Explanation: An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material that is normally silicon. |
|
| 994. |
The chemical name of "Plaster of Paris" commonly used for setting broken bones is – |
| A. | Calcium nitrate |
| B. | Calcium sulphate |
| C. | Calcium carbonate |
| D. | Calcium chloride |
| Answer» B. Calcium sulphate | |
|
Explanation: Plaster of Paris is the common name of Calcium Sulphate hemihydrate, with chemical formula: CaSO4.1/2H2O. Plaster of Paris is produced by heating gypsum to about 150°C. |
|
| 995. |
Which of the following is NOT malleable? |
| A. | Graphite |
| B. | Aluminium |
| C. | Copper |
| D. | Silver |
| Answer» A. Graphite | |
|
Explanation: Graphite is soft thanks to Van derWalls forces between to sheets of carbon atoms. |
|
| 996. |
The element found in the surface of the Moon is – |
| A. | Tin |
| B. | Tungsten |
| C. | Tantalum |
| D. | Titanium |
| Answer» D. Titanium | |
|
Explanation: Elements known to be present on the lunar surface include, among others, oxygen(O), silicon (Si), iron (Fe), magnesium (Mg), calcium (Ca), aluminium (Al),manganese (Mn) and titanium (Ti). |
|
| 997. |
Which of the following is not a chemical reaction'? |
| A. | Burning of paper |
| B. | Digestion of food |
| C. | Conversion of water into steam |
| D. | Burning of coal |
| Answer» C. Conversion of water into steam | |
|
Explanation: The conversion of water into steam is an example of a physical change. where the state of the matter changes without changing its composition. A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density. |
|
| 998. |
Which of the following is used as anesthetic? |
| A. | NH3 |
| B. | NO |
| C. | NO2 |
| D. | N2O |
| Answer» B. NO | |
|
Explanation: Nitrous oxide (NO), commonly known as laughing as or happy gas, is the most commonly used inhalation anesthetic in dentistry and is commonly used in emergency centers and ambulatory surgery centers as well. It is an inorganic inhalation agent that iscolorless, odorless to sweet-smelling, and nonirritating to the tissues. |
|
| 999. |
Gypsum is used for improvement of: |
| A. | Alkaline soils |
| B. | Saline soils |
| C. | (3) Podsols |
| D. | (4) Acidic soils |
| Answer» B. Saline soils | |
|
Explanation: Gypsum is calcium sulfate which is essential to the sustainability of most irrigated soils. Irrigated land eventually leads to sodieity and salinity unless extreme care is taken. It improves sodic (saline) soils by removing sodium from the soil and replacing it with calcium. |
|
| 1000. |
Spontaneous change is one in there is: |
| A. | A lowering of entropy |
| B. | A lowering of free energy |
| C. | Increase in free energy |
| D. | An increase in Internal energy |
| Answer» B. A lowering of free energy | |
|
Explanation: Entropy and enthalpy together make a new quantity, the Free Energy which, under conditions of constant temperature and pressure, determines the direction of spontaneous change. All spontaneous processes have a negative change in free energy. |
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