[1] The natural resource, known as black gold is –
A.
coal
B.
lead
C.
tin
D.
platinum
Ans:
coal
Explanation :
The term "coal is a black gold" is just a simple metaphor. Even today, we burn more coal than natural gas, more than nuclear, more than anything.
[2] This group of alumino-silicate minerals is widely used in making electrical insulators –
A.
Bauxite
B.
Chrornite
C.
Manganese
D.
Mica
Ans:
Mica
Explanation :
Sheet mica is used principally in the electronic and electrical industries. Its usefulness in these applications is derived from its unique electrical and thermal insulating properties and its mechanical properties, which allow it to be cut, punched, stamped, and machined to close tolerances. Specifically, Mica is unusual in that it is a good electrical insulator at the same time as being a good thermal conductor.
[3] Which of the following is a renewable source of energy?
A.
Coal
B.
Geothermal powder
C.
Natural gas
D.
Uranium
Ans:
Geothermal powder
Explanation :
Geothermal electricity is electricity generated from geothermal energy. Geothermal power is considered to be sustainable because the heat extraction is small compared with the Earth's heat content.
[4] The rate of change of linear momentum of a body falling freely under gravity is equal to it's .
A.
Kinetic Energy
B.
Weight
C.
Potential Energy
D.
Impulse
Ans:
Weight
Explanation :
Rate of change of impulse equals the force. In case of freely falling body the only force is the weight.
[5] Isobar is produced by the emission of which of the following?
A.
X-ray
B.
Gamma ray
C.
Beta ray
D.
Alpha ray
Ans:
Beta ray
Explanation :
Isobar, in nuclear physics, any member of a group of atomic or nuclear species all of which have the same mass number-that is, the same total number of protons and neutrons. In beta decay, mother and daughter nuclei are always isobars, because either a neutron is converted to a protonor a proton is converted to a neutron in the process.
[6] The main Constituent of natural gas is –
A.
Methane
B.
Ethane
C.
Butane
D.
Propane
Ans:
Methane
Explanation :
Natural has is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, with other hydrocarbons, carbon dioxide, nitrogen and hydrogen sulfide. It is found in deep underground natural rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is also another resource found in proximity to and with natural gas.
[7] Domestic cooking gas consists mostly of –
A.
methane and ethane
B.
liquefied butane and isobutene
C.
hydrogen and acetylene
D.
ethylene and carbon monoxide
Ans:
liquefied butane and isobutene
Explanation :
Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.
[8] An example of replenshible energy source is —
A.
Coal
B.
Petroleum
C.
Lignite
D.
Biomass
Ans:
Biomass
Explanation :
Biomass is biological material from living, or recently living organisms, most often referring to plants or plant-derived materials. As a renewable energy source, biomass can either be used directly, or indirectly #NAME?
[9] Which one of the following minerals is found in pure form?
A.
Iron
B.
Copper
C.
Bauxite
D.
Manganese
Ans:
Copper
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
The term "coal is a black gold" is just a simple metaphor. Even today, we burn more coal than natural gas, more than nuclear, more than anything.
[2] This group of alumino-silicate minerals is widely used in making electrical insulators –
A.
Bauxite
B.
Chrornite
C.
Manganese
D.
Mica
Ans:
Mica
Explanation :
Sheet mica is used principally in the electronic and electrical industries. Its usefulness in these applications is derived from its unique electrical and thermal insulating properties and its mechanical properties, which allow it to be cut, punched, stamped, and machined to close tolerances. Specifically, Mica is unusual in that it is a good electrical insulator at the same time as being a good thermal conductor.
[3] Which of the following is a renewable source of energy?
A.
Coal
B.
Geothermal powder
C.
Natural gas
D.
Uranium
Ans:
Geothermal powder
Explanation :
Geothermal electricity is electricity generated from geothermal energy. Geothermal power is considered to be sustainable because the heat extraction is small compared with the Earth's heat content.
[4] The rate of change of linear momentum of a body falling freely under gravity is equal to it's .
A.
Kinetic Energy
B.
Weight
C.
Potential Energy
D.
Impulse
Ans:
Weight
Explanation :
Rate of change of impulse equals the force. In case of freely falling body the only force is the weight.
[5] Isobar is produced by the emission of which of the following?
A.
X-ray
B.
Gamma ray
C.
Beta ray
D.
Alpha ray
Ans:
Beta ray
Explanation :
Isobar, in nuclear physics, any member of a group of atomic or nuclear species all of which have the same mass number-that is, the same total number of protons and neutrons. In beta decay, mother and daughter nuclei are always isobars, because either a neutron is converted to a protonor a proton is converted to a neutron in the process.
[6] The main Constituent of natural gas is –
A.
Methane
B.
Ethane
C.
Butane
D.
Propane
Ans:
Methane
Explanation :
Natural has is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, with other hydrocarbons, carbon dioxide, nitrogen and hydrogen sulfide. It is found in deep underground natural rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is also another resource found in proximity to and with natural gas.
[7] Domestic cooking gas consists mostly of –
A.
methane and ethane
B.
liquefied butane and isobutene
C.
hydrogen and acetylene
D.
ethylene and carbon monoxide
Ans:
liquefied butane and isobutene
Explanation :
Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.
[8] An example of replenshible energy source is —
A.
Coal
B.
Petroleum
C.
Lignite
D.
Biomass
Ans:
Biomass
Explanation :
Biomass is biological material from living, or recently living organisms, most often referring to plants or plant-derived materials. As a renewable energy source, biomass can either be used directly, or indirectly #NAME?
[9] Which one of the following minerals is found in pure form?
A.
Iron
B.
Copper
C.
Bauxite
D.
Manganese
Ans:
Copper
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Geothermal electricity is electricity generated from geothermal energy. Geothermal power is considered to be sustainable because the heat extraction is small compared with the Earth's heat content.
[4] The rate of change of linear momentum of a body falling freely under gravity is equal to it's .
A.
Kinetic Energy
B.
Weight
C.
Potential Energy
D.
Impulse
Ans:
Weight
Explanation :
Rate of change of impulse equals the force. In case of freely falling body the only force is the weight.
[5] Isobar is produced by the emission of which of the following?
A.
X-ray
B.
Gamma ray
C.
Beta ray
D.
Alpha ray
Ans:
Beta ray
Explanation :
Isobar, in nuclear physics, any member of a group of atomic or nuclear species all of which have the same mass number-that is, the same total number of protons and neutrons. In beta decay, mother and daughter nuclei are always isobars, because either a neutron is converted to a protonor a proton is converted to a neutron in the process.
[6] The main Constituent of natural gas is –
A.
Methane
B.
Ethane
C.
Butane
D.
Propane
Ans:
Methane
Explanation :
Natural has is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, with other hydrocarbons, carbon dioxide, nitrogen and hydrogen sulfide. It is found in deep underground natural rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is also another resource found in proximity to and with natural gas.
[7] Domestic cooking gas consists mostly of –
A.
methane and ethane
B.
liquefied butane and isobutene
C.
hydrogen and acetylene
D.
ethylene and carbon monoxide
Ans:
liquefied butane and isobutene
Explanation :
Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.
[8] An example of replenshible energy source is —
A.
Coal
B.
Petroleum
C.
Lignite
D.
Biomass
Ans:
Biomass
Explanation :
Biomass is biological material from living, or recently living organisms, most often referring to plants or plant-derived materials. As a renewable energy source, biomass can either be used directly, or indirectly #NAME?
[9] Which one of the following minerals is found in pure form?
A.
Iron
B.
Copper
C.
Bauxite
D.
Manganese
Ans:
Copper
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Isobar, in nuclear physics, any member of a group of atomic or nuclear species all of which have the same mass number-that is, the same total number of protons and neutrons. In beta decay, mother and daughter nuclei are always isobars, because either a neutron is converted to a protonor a proton is converted to a neutron in the process.
[6] The main Constituent of natural gas is –
A.
Methane
B.
Ethane
C.
Butane
D.
Propane
Ans:
Methane
Explanation :
Natural has is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, with other hydrocarbons, carbon dioxide, nitrogen and hydrogen sulfide. It is found in deep underground natural rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is also another resource found in proximity to and with natural gas.
[7] Domestic cooking gas consists mostly of –
A.
methane and ethane
B.
liquefied butane and isobutene
C.
hydrogen and acetylene
D.
ethylene and carbon monoxide
Ans:
liquefied butane and isobutene
Explanation :
Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.
[8] An example of replenshible energy source is —
A.
Coal
B.
Petroleum
C.
Lignite
D.
Biomass
Ans:
Biomass
Explanation :
Biomass is biological material from living, or recently living organisms, most often referring to plants or plant-derived materials. As a renewable energy source, biomass can either be used directly, or indirectly #NAME?
[9] Which one of the following minerals is found in pure form?
A.
Iron
B.
Copper
C.
Bauxite
D.
Manganese
Ans:
Copper
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Domestic gas is another name for Liquefied Petroleum Gas (LPG). Varieties of LPG bought and sold include mixes that are primarily propane (C3H8), primarily butane (C4H10) and, most commonly, mixes including both propane and butane, depending on the season — in winter more propane, in summer more butane.
[8] An example of replenshible energy source is —
A.
Coal
B.
Petroleum
C.
Lignite
D.
Biomass
Ans:
Biomass
Explanation :
Biomass is biological material from living, or recently living organisms, most often referring to plants or plant-derived materials. As a renewable energy source, biomass can either be used directly, or indirectly #NAME?
[9] Which one of the following minerals is found in pure form?
A.
Iron
B.
Copper
C.
Bauxite
D.
Manganese
Ans:
Copper
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Copper is one of very few elements that are found in essentially pure form in nature. But the bulk of the copper resource is found in other minerals.
[10] Bleaching powder is used in drinking water as a/an –
A.
disinfectant
B.
antibiotic
C.
antiseptic
D.
coagulant
Ans:
disinfectant
Explanation :
Bleach refers to a number of chemicals which remove colour, whiten or disinfect, often via oxidation. Bleaches are used as household chemicals to whiten clothes and remove stains and as disinfectants, primarily in the bathroom and kitchen. Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing and thus are used in swimming pool sanitation to control bacteria, viruses and algae and in any institution where sterile conditions are needed.
[11] The iron ore which contains 72% of iron is –
A.
Magnetite
B.
Limonite
C.
Haematite
D.
Siderite
Ans:
Magnetite
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Iron (Fe) is a metallic element and composes about 5% of the Earth's crust. When pure it is a dark, silvery-gray metal. It is a very reactive element and oxidizes (rusts) very easily. The reds, oranges and yellows seen in some soils and on rocks are probably iron oxides. The inner core of the Earth is believed to be a solid iron-nickel alloy. Iron-nickel meteorites are believed to represent the earliest material formed at the beginning of the universe.
[12] Cement is formed by strongly heating a mixture of –
A.
limestone and graphite
B.
limestone and clay
C.
chalk and graphite
D.
clay and graphite
Ans:
limestone and clay
Explanation :
Cement is made by heating limestone (calcium carbonate) with small quantities of other materials (such as clay) to 1450 degree C in a kiln, in a process known as calcinations, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix.
[13] Glass is a –
A.
superheated solid
B.
supercooled liquid
C.
supercooled gas
D.
superheated liquid
Ans:
supercooled liquid
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Glass is an amorphous (non-crystalline) solid material. Glasses are typically brittle and optically transparent. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the super- cooled liquid is frozen into the solid state at Tg. Generally, the structure of a glass exists in a meta-stable state with respect to its crystalline form.
[14] Which one of the following metals does not react with water to produce Hydrogen?
A.
Potassium
B.
Cadmium
C.
Sodium
D.
Lithium
Ans:
Cadmium
Explanation :
Cadmium is a soft, malleable, ductile, bluish-white divalent metal. It is similar in many respects to zinc but forms complex compounds. Unlike other metals, cadmium is resistant to corrosion and as a result it is used as a protective layer when deposited on other metals. As a bulk metal, cadmium is insoluble in water and is not flammable; however, in its powdered form it may burn and release toxic fumes. Cadmium occurs as a minor component in most zinc ores and therefore is a byproduct of zinc production.
[15] Ozone consists of -
A.
Oxygen only
B.
Oxygen and Nitrogen
C.
Hydrogen and Carbon
D.
Oxygen and Carbon
Ans:
Oxygen only
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Ozone (O3), or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of roughly 30 minutes in the lower atmosphere, to normal dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere.
[16] The greenhouse effect is caused by the higher level of which gas in the atmosphere?
A.
Carbon monoxide
B.
Carbon dioxide
C.
Nitrous oxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. The environmental effects of carbon dioxide are of significant interest.
[17] Which one of the following is extensively used for sterilizing water?
A.
Bleaching powder
B.
Alum
C.
Borax powder
D.
Soda powder
Ans:
Bleaching powder
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Bleaching powder is extensively used in sterilizing water. Calcium hypochlorite is a chemical compound with formula Ca(OCl)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochicnite (liquid bleach). Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water, and is more preferably used in soft to medium-hard water. It has two forms: a dry form and a hydrated form. The hydrated form is safer to handle.
[18] Which one of the following acids is used in battery?
A.
Hydrochloric acid
B.
Hydrofluoric acid
C.
Sulphuric acid
D.
Sulphurous acid
Ans:
Sulphuric acid
Explanation :
Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties, the sulfuric acid has a wide range of applications including domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.
[19] Natural rubber is a polymer derived from -
A.
ethylene
B.
propylene
C.
isoprene
D.
butadiene
Ans:
isoprene
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Isoprene was first isolated by thermal decomposition of natural rubber. About 95% of isoprene production is used to produce cis-1,4polyisoprene—a synthetic version of natural rubber.
[20] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
Fluorine is one of the most reactive elements in existence, attacking otherwise inert materials such as glass, and forming compounds with the heavier noble gases. It is a corrosive and highly toxic gas. The reactivity of fluorine is such that if used or stored in laboratory glassware, it can react with glass in the presence of small amounts of water to form silicon tetrafluoride (SiF4).
[21] Which one of the following is radioactive?
A.
Cesium
B.
Platinum
C.
Strontium
D.
Thorium
Ans:
Thorium
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Thorium is a naturally occurring radioactive chemical element with the symbol ‘Th’ and atomic number 90. It was discovered in 1828 by the Norwegian mineralogist Morten ThraneEsmark and identified by the Swedish chemist JonsJakob Berzelius and named after Thor, the Norse god of thunder. In nature, virtually all thorium is found as thorium-232, which undergoes alpha decay with a half-life of about 14.05 billion years. Other isotopes of thorium are short-lived intermediates in the decay chains of higher elements, and only found in trace amounts.
[22] When iron rusts, its weight :
A.
decreases
B.
increases
C.
remains the same
D.
first increases and then decreases
Ans:
increases
Explanation :
When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
[23] Which of the following is used as filler in tyre of rubber?
A.
Carbon black
B.
Coal
C.
Coke
D.
Graphite
Ans:
Carbon black
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life.
[24] Which of the following alloy is used in making magnet?
A.
Duralumin
B.
Stainless steel
C.
Elniko
D.
Magnalium
Ans:
Elniko
Explanation :
A magnetic alloy is a combination of various metals from the periodic table that contains at least one of the three main magnetic elements: iron (Fe), nickel (Ni), and cobalt (Co).
[25] The enzyme that converts glucose to ethyl alcohol is –
A.
invertase
B.
Maltase
C.
Zymase
D.
Diastase
Ans:
Zymase
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.
Explanation :
Explanation: ‘ The fermentation of sugar into ethanol is one of the earliest biotechnologies employed by humanity. Fermentation of fermentable sugars by suitable yeast produces ethanol (ethyl alcohol). Yeast is a single celled fungus containing a number of enzymes useful during fermentation. Brewers yeast and wine yeast, for example, contain zymase, an enzyme that can convert glucose to ethanol.