McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 651. |
is a by product of sewage treatment and can be decomposed to produce biogas. |
| A. | Sewage |
| B. | Sludge |
| C. | Sewer |
| D. | Scum |
| Answer» B. Sludge | |
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Explanation: Sludge refers to the residual, semi-solid material that is produced as a by- product during sewage treatment of industrial or municipal wastewater. It can be used to produce biogas through a process called anaerobic digestion or fermentation. |
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| 652. |
Silver gets corroded due to in air. |
| A. | Oxygen |
| B. | Hydrogen Sulphide |
| C. | Carbon dioxide |
| D. | Nitrogen |
| Answer» B. Hydrogen Sulphide | |
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Explanation: Silver is a fairly stable metal and under normal circumstances does not corrode quickly. However, it is particularly susceptible to the effects of the sulfide radical. However, when exposed to air, silver reacts with Hydrogen Sulphide in the atmosphere, especially in marine environment, and readily forms a surface tarnish of silver sulphide. |
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| 653. |
Which of the following is a radioactive element? |
| A. | Cobalt |
| B. | Uranium |
| C. | Argon |
| D. | Chromium |
| Answer» B. Uranium | |
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Explanation: Uranium (U) is a naturally occurring radioactive element. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable arrangement. One of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear |
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| 654. |
Whatis Zeolite? |
| A. | Hydrated Aluminosilicate |
| B. | Hydrated Calcium Sulphate |
| C. | Dehydrated Aluminosilicate |
| D. | Dehydrated Calcium Sulphate |
| Answer» A. Hydrated Aluminosilicate | |
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Explanation: Zeolites are hydrated aluminosilicate minerals made from interlinked tetrahedra of alumina (AlO4) and silica (SiO4). In simpler words, they're solids with a relatively open, three-dimensional crystal structure built from the elements aluminium, oxygen, and silicon, with alkali or alkaline-Earth metals (such as sodium, potassium, and magnesium) plus water molecules trapped in the gaps between them. |
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| 655. |
L.P.G. is mostly liquefied |
| A. | hydrogen |
| B. | Oxygen |
| C. | butane |
| D. | methane |
| Answer» C. butane | |
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Explanation: Liquefied petroleum gas or liquid petroleum gas (LPG) is mostly propane (C3H8), or butane (C4H10). They are most commonly mixtures of these two hydrocarbon gases that are used as fuel in heating appliances, cooking equipment, and vehicles. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane. |
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| 656. |
Which have the maximum density? |
| A. | Water |
| B. | Benzene |
| C. | Ice |
| D. | Chloroform |
| Answer» A. Water | |
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Explanation: Water has its maximum density of 1g/cm3 at 4 degrees Celsius. When the temperature changes from either greater or lessthan 4 degrees, the density will become less than 1 g/cm3. |
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| 657. |
Which of the following metals is stored in kerosene oil? |
| A. | Platinum |
| B. | Copper |
| C. | Sodium |
| D. | Gold |
| Answer» C. Sodium | |
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Explanation: Owing to its extreme reactivity, sodium occurs in nature only combined in compounds never as a pure elemental metal. |
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| 658. |
Atoms having the same number of protons but different number of neutrons are called : |
| A. | Isotopes |
| B. | Cations |
| C. | Higgs-boson |
| D. | Anions . |
| Answer» A. Isotopes | |
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Explanation: Atoms that have the same number of protons but different numbers of neutrons are called isotopes. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14 respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons, so that the neutron numbers of these isotopes are 6, 7 and 8 respectively. |
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| 659. |
Which one of the following elements is least likely to be found in commercial fertilisers? |
| A. | Nitrogen |
| B. | Phosphorus |
| C. | Potassium |
| D. | Silicon |
| Answer» D. Silicon | |
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Explanation: Commercial Fertilizers - a substance containing one or more recognized plant nutrients and that is used for its plant nutrient content or that is designated for use or claimed to have value in promoting plant growth. |
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| 660. |
Organic compounds are - |
| A. | Covalent compounds |
| B. | Ionic compounds |
| C. | Co-ordination compounds |
| D. | Interstitial compounds |
| Answer» A. Covalent compounds | |
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Explanation: Organic compounds are always covalent compounds because it is more energetically favorable for carbon to covalently bond. Organic compounds, such as carbohydrates, lipids, proteins and nucleic acids, are all examples of covalent compounds. |
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| 661. |
Which of the following is NOT a renewable source of energy? |
| A. | Wind energy |
| B. | Geothermal energy |
| C. | Energy from fossils |
| D. | Solar energy |
| Answer» C. Energy from fossils | |
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Explanation: Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight wind, rain, tides, waves, and geothermal heat. |
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| 662. |
Compounds of carbon having double or triple bonds between their carbon atoms are called |
| A. | Saturated compounds |
| B. | Unsaturated compounds |
| C. | Reactive compounds |
| D. | None of the above |
| Answer» B. Unsaturated compounds | |
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Explanation: Compounds of carbon, which are linked by only single bonds between the carbon atoms are called saturated compounds. Compounds of carbon having double or triple bonds between their carbon atoms are called unsaturated compounds. |
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| 663. |
An alloy used in making heating elements for electric heating device is - |
| A. | Solder |
| B. | Alloy Steel |
| C. | Nichrome |
| D. | German Silver |
| Answer» C. Nichrome | |
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Explanation: Nichrome is a mixture of chromium and nickel. Nichrome wire is a great conductor of electricity. Nichrome is used to make heating coils and other types of elements in household appliances. |
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| 664. |
The degree of dissociation of an electrolyte depends on - |
| A. | dilution |
| B. | impurities |
| C. | atmospheric pressure |
| D. | method of dissolution |
| Answer» A. dilution | |
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Explanation: The extent to which an electrolyte dissociates into ions is known as degree of dissociation or ionization and depends upon the following factors: (1) Nature of the electrolyte,(2) Temperature, (3) Dilution, (4) nature of the solvent, and (e) presence of other ions. |
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| 665. |
Which of the following is present in Nail polish remover? |
| A. | Citric acid |
| B. | Acetone |
| C. | Ethylene |
| D. | Benzene |
| Answer» B. Acetone | |
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Explanation: Acetone can also remove artificial nails made of acrylic or cured gel. An alternative nail polish remover is ethyl acetate, which often also contains isopropyl alcohol. |
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| 666. |
Glass is mainly composed of - |
| A. | Sodium silicate |
| B. | Calcium carbonate |
| C. | Calcium hydroxide |
| D. | Sodium bicarbonate |
| Answer» A. Sodium silicate | |
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Explanation: Glass is made from silica (SiO₂) and soda lime, which react to form sodium silicate. |
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| 667. |
Which of the following is essential for the synthesis of thyroxin? |
| A. | Potassium |
| B. | Sodium |
| C. | Calcium |
| D. | Iodine |
| Answer» D. Iodine | |
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Explanation: Iodine is essential for the synthesis of Thyroxine, one of the two major hormones secreted by the thyroid gland. Thyroxine is formed by the molecular addition of iodine to the amino acid tyrosine while the latter is bound to the protein thyroglobulin. |
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| 668. |
Chlorophyll is porphyrin containing - |
| A. | magnesium |
| B. | iron |
| C. | calcium |
| D. | (4) tin |
| Answer» A. magnesium | |
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Explanation: Chlorophyll are greenish pigment which contain a porphyrin ring. This is a stable ring-shaped molecule around which electrons are free to migrate. Magnesium is central atom in porphyrin structure of chlorophyll. |
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| 669. |
Which of the following processes is used for the production of Biodiesel? |
| A. | Transamination |
| B. | Transcription |
| C. | Transesterification |
| D. | Translation |
| Answer» C. Transesterification | |
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Explanation: Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions trans- esterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or ethanol). |
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| 670. |
A matured mammalian cell without nucleus is – |
| A. | Lymphocyte |
| B. | Erythrocyte |
| C. | Spermatozoan |
| D. | Oocyte |
| Answer» B. Erythrocyte | |
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Explanation: Mammalian erythrocytes are unique among the vertebrates as they are non- nucleated cells in their mature form. These cells have nuclei during early phases of erythropoiesis, but extrude them during development as they mature in order to provide more space for hemoglobin. In mammals, erythrocytes also lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum. |
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| 671. |
The most common cause of pollution of air is – |
| A. | Carbon dioxide |
| B. | Carbon monoxide |
| C. | Sulphur dioxide |
| D. | Smoke |
| Answer» C. Sulphur dioxide | |
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Explanation: The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. It is linked with a number of adverse effects on the respiratory system. |
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| 672. |
The main source of carbon monoxide is |
| A. | Industrial process |
| B. | Fuel combustion |
| C. | Transportation |
| D. | Solid waste disposal |
| Answer» C. Transportation | |
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Explanation: The main source of carbon monoxide is burning of fossil fuel |
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| 673. |
Tooth enamel is the hardest substance found in the human body. What is it made up of - |
| A. | Calcium carbonate |
| B. | Limestone |
| C. | Calcium phosphate |
| D. | Calcium fluoride |
| Answer» C. Calcium phosphate | |
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Explanation: The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds. |
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| 674. |
A solution turns blue litmus red, its pH is likely to be - |
| A. | 11 |
| B. | 9 |
| C. | 5 |
| D. | 10 |
| Answer» C. 5 | |
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Explanation: If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base. |
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| 675. |
Which of the following metals is used in Space Crafts to withstand high temperatures? |
| A. | Fe |
| B. | Ti |
| C. | Ni |
| D. | Pb |
| Answer» B. Ti | |
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Explanation: Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures. |
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| 676. |
Brass gets discoloured in air due to constant exposure in presence of: |
| A. | Aluminium phosphide |
| B. | Hydrogen sulphide |
| C. | Hydrogenated wafers |
| D. | Aluminium sulphide |
| Answer» B. Hydrogen sulphide | |
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Explanation: Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air. |
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| 677. |
Neutrons are slowed down in a nuclear reactor by – |
| A. | Fissionable Material |
| B. | Moderator |
| C. | Control rods |
| D. | Cooling system |
| Answer» B. Moderator | |
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Explanation: In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission. |
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| 678. |
An element of atomic no. 29 belongs to |
| A. | s-block |
| B. | d-block |
| C. | p-block |
| D. | f-block |
| Answer» B. d-block | |
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Explanation: Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance. |
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| 679. |
Mechanical energy is the combination of kinetic energy and . |
| A. | Heat energy |
| B. | Chemical energy |
| C. | Potential energy |
| D. | Nuclear energy |
| Answer» C. Potential energy | |
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Explanation: Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy. |
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| 680. |
Magnetism at the centre of a bar magnet is - |
| A. | minimum |
| B. | maximum |
| C. | zero |
| D. | minimum or maximum |
| Answer» C. zero | |
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Explanation: The field at the center is not zero, but weak. At the exact center of a magnet thefield lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent. |
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| 681. |
Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called - |
| A. | Catalysts |
| B. | Hydrocarbons |
| C. | Oxidising agents |
| D. | Substitutes |
| Answer» A. Catalysts | |
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Explanation: Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst. |
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| 682. |
Which one of the following elements exhibits the greatest tendency to lose electrons? |
| A. | Fluorine |
| B. | Lithium |
| C. | Oxygen |
| D. | Zine |
| Answer» B. Lithium | |
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Explanation: Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions. |
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| 683. |
Poison used for killing rats is – |
| A. | Calcium phosphide (Ca3P2) |
| B. | Zinc phosphide (Zn3P2) |
| C. | Magnesium nitride (Mg3N2) |
| D. | Magnesium phosphide (Mg3P2) |
| Answer» B. Zinc phosphide (Zn3P2) | |
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Explanation: Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals. |
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| 684. |
The commonly used safety fuse-wire is made of - |
| A. | an alloy of Nickel and Lead |
| B. | an alloy of Tin and Lead |
| C. | an alloy of Tin and Nickel |
| D. | an alloy of Lead and Iron |
| Answer» B. an alloy of Tin and Lead | |
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Explanation: As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof. |
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| 685. |
Lead pencil contains - |
| A. | Lead nitrate |
| B. | Graphite |
| C. | Lead peroxide |
| D. | Lead Sulphate |
| Answer» B. Graphite | |
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Explanation: Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased. |
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| 686. |
The most suitable unit for expressing nuclear radius is - |
| A. | nanometre |
| B. | fermi |
| C. | angstrom |
| D. | micron |
| Answer» B. fermi | |
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Explanation: The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius. |
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| 687. |
The catalyst used in hydrogenation of oils is - |
| A. | Fe |
| B. | V2O5 |
| C. | Ni |
| D. | O2 |
| Answer» C. Ni | |
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Explanation: The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation. |
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| 688. |
What is used in storage batteries? |
| A. | Copper |
| B. | Tin |
| C. | Lead |
| D. | Zinc |
| Answer» C. Lead | |
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Explanation: The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time. |
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| 689. |
The biogas used for cooking is a mixture of which of the following? |
| A. | Carbon dioxide and oxygen |
| B. | Isobutane and propane |
| C. | Methane and Carbon monoxide |
| D. | Methane and carbon dioxide |
| Answer» D. Methane and carbon dioxide | |
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Explanation: Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25- 30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel. |
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| 690. |
Ozone saves the biosphere by absorbing high energy radiations called - |
| A. | Infra-red |
| B. | Gamma rays |
| C. | Ultraviolet rays (UV) |
| D. | X-rays |
| Answer» C. Ultraviolet rays (UV) | |
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Explanation: The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface. |
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| 691. |
Silica gel is a - |
| A. | moisturizer |
| B. | flavouring agent |
| C. | drying agent |
| D. | delicious food |
| Answer» C. drying agent | |
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Explanation: Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads. |
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| 692. |
Neutron was discovered by - |
| A. | Chadwick |
| B. | Rutherford |
| C. | Fermi |
| D. | Bohr |
| Answer» A. Chadwick | |
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Explanation: Neutron was discovered by James Chadwick in the year 1932. The neutron is a subatomic particle, symbol n or n⁰, with no net electric charge and a mass slightly larger than that of a proton. Protons and neutrons constitute the nuclei of atoms. |
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| 693. |
Iodine can be separated from a mixture of Iodine and Potassium Chloride by - |
| A. | Filtration |
| B. | Sublimation |
| C. | Distillation |
| D. | Sedimentation |
| Answer» B. Sublimation | |
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Explanation: Iodine can be separated from a mixture of Iodine and Potassium Chloride by Sublimation. Sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase. |
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| 694. |
Which of the following produces H2 gas, when reacts with acid? |
| A. | Zn |
| B. | S |
| C. | C |
| D. | O |
| Answer» A. Zn | |
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Explanation: As, Zinc is a metal so it will produce H2 gas when reacts with acid. Active metals react with acids to produce hydrogen because they are above hydrogen in the activity series. |
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| 695. |
Which one of the following is commonly used for pulp bleaching in the paper industry? |
| A. | Mild sulphuric acid |
| B. | Glucose isomerase |
| C. | Hydrogen peroxide |
| D. | Iodine and water |
| Answer» C. Hydrogen peroxide | |
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Explanation: Bleaching of wood pulp is the chemical processing carried out to decrease the color of the pulp, so that it becomes whiter. Alkaline hydrogen peroxide is the most commonly used bleaching agent for mechanical pulp. It selectively oxidizes non-aromatic conjugated groups responsible for absorbing visible light. The decomposition of hydrogen peroxide is catalyzed by transition metals. |
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| 696. |
Biofertilizers convert nitrogen to |
| A. | nitrates |
| B. | ammonia |
| C. | nitrogenase |
| D. | amino acids |
| Answer» B. ammonia | |
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Explanation: Bio-fertilizers are micro- organisms which bring about nutrientenrichment of soil by enhancing the availability of nutrients to crops. The micro-organisms which act as bio-fertilizers are bacteria, cyanobacteria (blue green algae) and mycorrhizal fungi. The symbiotic nitrogen- fixing bacteria convert free nitrogen to ammonia, which the host plant utilizes for its development. |
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| 697. |
Radioactivity was discovered by |
| A. | J.J. Thomson |
| B. | W.Roentgen |
| C. | H.Becquerel |
| D. | M. Curie |
| Answer» C. H.Becquerel | |
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Explanation: Antoine-Henri Becquerel is known for his discovery of radioactivity, for which he received the Nobel Prize for Physics in 1903. Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. |
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| 698. |
Which one of the following can be oxidized to the corresponding carbonyl compound - |
| A. | O-Nitrophenol |
| B. | Phenol |
| C. | 2-methyl-2-hydroxy propane |
| D. | 2-hydroxy propane |
| Answer» D. 2-hydroxy propane | |
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Explanation: 0 |
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| 699. |
gives hardness to stainless steel. |
| A. | Zinc |
| B. | Lead |
| C. | Carbon |
| D. | Tin |
| Answer» C. Carbon | |
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Explanation: Iron is alloyed with carbon lo make steel and has the effect of increasing the hardness and strength of iron. Pure iron cannot be hardened or strengthened by heat treatment but the addition of carbon enables a wide range of hardness and strength. High-carbon stainless steel contains a minimum of 0.3% carbon. The higher the carbon content, the less formable and the tougher the steel becomes. |
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| 700. |
Which of the following is not soluble in water? |
| A. | Lead Sulphate |
| B. | Zinc sulphate |
| C. | Potassium sulphate |
| D. | Sodium sulphate |
| Answer» B. Zinc sulphate | |
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Explanation: Lead sulfate (PbSO4) is a white crystalline solid. It is insoluble in water and sinks in it. It is often seen in the plates/electrodes of car batteries, as it is formed when the battery is discharged. It is also known as fast white, milk white, sulfuric acid lead salt or anglesite. |
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