[1] Which of the following is used to iodise common salt?
A.
Potassium iodide
B.
Iodine
C.
Potassium iodate
D.
Sodium iodide
Ans:
Potassium iodate
Explanation :
Iodized salt (also spelled iodised salt) is table salt mixed with a minute amount of various salts of the element iodine. Table salt with iodide salt slowly loses its iodine content through the process of oxidation and iodine evaporation. Edible salt can be iodised by spraying it with a potassium iodate solution. 60 ml of potassium iodate.
[2] Which of the following imparts deep blue colour to glass?
A.
Cobalt oxide
B.
Cupric oxide
C.
Ferrous oxide
D.
Nickel oxide
Ans:
Nickel oxide
Explanation :
Glass colouring and colour marking may be obtained by addition of colouring ions, by precipitation of nanometer sized colloides (so-called striking glasses such as "ruby gold" or red "selenium ruby"), by coloured inclusions (as in milk glass and smoked glass).
[3] Which of the following fibres catches fire least?
A.
Nylon
B.
Cotton
C.
Rayon
D.
Terricot
Ans:
Cotton
Explanation :
The fibre least prone to catch fire is cotton. Fabrics with more of the fiber surface area exposed to air have more oxygen available to support, burning and therefore burn more easily. Thus, thin, gauzy fabrics, lace, or brushed fabrics can be very flammable.
[4] Drinking soda is –
A.
Alkaline
B.
Acidic
C.
Neutral
D.
Oxidant
Ans:
Acidic
Explanation :
A soft drink, coke, soda pop, fizzy drink, tonic, seltzer, mineral, sparkling water or carbonated beverage) is a beverage that typically contains water (often, but not always carbonated water), usually a sweetener, and usually a flavoring agent. The sweetener may be sugar, high-fructose corn syrup, fruit juice, sugar substitutes (in the case of diet drinks) or a combination of these. Soft drinks may also contain caffeine, colourings, preservatives and other ingredients. Soft drinks are called "soft" in contrast to "hard drinks" (alcoholic beverages).
[5] The cathode of a lead storage battery is made up of –
A.
Zinc
B.
Lead
C.
Lead oxide
D.
Manganese dioxide
Ans:
Lead
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[6] Who is regarded as father of modern chemistry?
A.
Ruterford
B.
Einstein
C.
Lavoisier
D.
C.V. Raman
Ans:
Lavoisier
Explanation :
Antoine Lavoisier is considered the father of modern chemistry. He was a French nobleman who recognized and named oxygen and isolated the major components of air.
[7] Kidney stones are mainly formed by which of the following compound -
A.
Sodium chloride
B.
Silicates
C.
Calcium bicarbonate
D.
Calcium oxalate
Ans:
Calcium oxalate
Explanation :
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
[8] What is the principal ore of aluminium?
A.
Dolomite
B.
Copper
C.
Lignite
D.
Bauxite
Ans:
Bauxite
Explanation :
Bacodte is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.
[9] Which gas is used as fire extinguisher?
A.
Carbon dioxide
B.
Carbon monoxide
C.
Carbon suboxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Iodized salt (also spelled iodised salt) is table salt mixed with a minute amount of various salts of the element iodine. Table salt with iodide salt slowly loses its iodine content through the process of oxidation and iodine evaporation. Edible salt can be iodised by spraying it with a potassium iodate solution. 60 ml of potassium iodate.
[2] Which of the following imparts deep blue colour to glass?
A.
Cobalt oxide
B.
Cupric oxide
C.
Ferrous oxide
D.
Nickel oxide
Ans:
Nickel oxide
Explanation :
Glass colouring and colour marking may be obtained by addition of colouring ions, by precipitation of nanometer sized colloides (so-called striking glasses such as "ruby gold" or red "selenium ruby"), by coloured inclusions (as in milk glass and smoked glass).
[3] Which of the following fibres catches fire least?
A.
Nylon
B.
Cotton
C.
Rayon
D.
Terricot
Ans:
Cotton
Explanation :
The fibre least prone to catch fire is cotton. Fabrics with more of the fiber surface area exposed to air have more oxygen available to support, burning and therefore burn more easily. Thus, thin, gauzy fabrics, lace, or brushed fabrics can be very flammable.
[4] Drinking soda is –
A.
Alkaline
B.
Acidic
C.
Neutral
D.
Oxidant
Ans:
Acidic
Explanation :
A soft drink, coke, soda pop, fizzy drink, tonic, seltzer, mineral, sparkling water or carbonated beverage) is a beverage that typically contains water (often, but not always carbonated water), usually a sweetener, and usually a flavoring agent. The sweetener may be sugar, high-fructose corn syrup, fruit juice, sugar substitutes (in the case of diet drinks) or a combination of these. Soft drinks may also contain caffeine, colourings, preservatives and other ingredients. Soft drinks are called "soft" in contrast to "hard drinks" (alcoholic beverages).
[5] The cathode of a lead storage battery is made up of –
A.
Zinc
B.
Lead
C.
Lead oxide
D.
Manganese dioxide
Ans:
Lead
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[6] Who is regarded as father of modern chemistry?
A.
Ruterford
B.
Einstein
C.
Lavoisier
D.
C.V. Raman
Ans:
Lavoisier
Explanation :
Antoine Lavoisier is considered the father of modern chemistry. He was a French nobleman who recognized and named oxygen and isolated the major components of air.
[7] Kidney stones are mainly formed by which of the following compound -
A.
Sodium chloride
B.
Silicates
C.
Calcium bicarbonate
D.
Calcium oxalate
Ans:
Calcium oxalate
Explanation :
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
[8] What is the principal ore of aluminium?
A.
Dolomite
B.
Copper
C.
Lignite
D.
Bauxite
Ans:
Bauxite
Explanation :
Bacodte is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.
[9] Which gas is used as fire extinguisher?
A.
Carbon dioxide
B.
Carbon monoxide
C.
Carbon suboxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
The fibre least prone to catch fire is cotton. Fabrics with more of the fiber surface area exposed to air have more oxygen available to support, burning and therefore burn more easily. Thus, thin, gauzy fabrics, lace, or brushed fabrics can be very flammable.
[4] Drinking soda is –
A.
Alkaline
B.
Acidic
C.
Neutral
D.
Oxidant
Ans:
Acidic
Explanation :
A soft drink, coke, soda pop, fizzy drink, tonic, seltzer, mineral, sparkling water or carbonated beverage) is a beverage that typically contains water (often, but not always carbonated water), usually a sweetener, and usually a flavoring agent. The sweetener may be sugar, high-fructose corn syrup, fruit juice, sugar substitutes (in the case of diet drinks) or a combination of these. Soft drinks may also contain caffeine, colourings, preservatives and other ingredients. Soft drinks are called "soft" in contrast to "hard drinks" (alcoholic beverages).
[5] The cathode of a lead storage battery is made up of –
A.
Zinc
B.
Lead
C.
Lead oxide
D.
Manganese dioxide
Ans:
Lead
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[6] Who is regarded as father of modern chemistry?
A.
Ruterford
B.
Einstein
C.
Lavoisier
D.
C.V. Raman
Ans:
Lavoisier
Explanation :
Antoine Lavoisier is considered the father of modern chemistry. He was a French nobleman who recognized and named oxygen and isolated the major components of air.
[7] Kidney stones are mainly formed by which of the following compound -
A.
Sodium chloride
B.
Silicates
C.
Calcium bicarbonate
D.
Calcium oxalate
Ans:
Calcium oxalate
Explanation :
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
[8] What is the principal ore of aluminium?
A.
Dolomite
B.
Copper
C.
Lignite
D.
Bauxite
Ans:
Bauxite
Explanation :
Bacodte is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.
[9] Which gas is used as fire extinguisher?
A.
Carbon dioxide
B.
Carbon monoxide
C.
Carbon suboxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Lead-acid batteries, invented in 1859 by French physicist Gaston Plante, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large power weight ratio. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by automobile starter motors.
[6] Who is regarded as father of modern chemistry?
A.
Ruterford
B.
Einstein
C.
Lavoisier
D.
C.V. Raman
Ans:
Lavoisier
Explanation :
Antoine Lavoisier is considered the father of modern chemistry. He was a French nobleman who recognized and named oxygen and isolated the major components of air.
[7] Kidney stones are mainly formed by which of the following compound -
A.
Sodium chloride
B.
Silicates
C.
Calcium bicarbonate
D.
Calcium oxalate
Ans:
Calcium oxalate
Explanation :
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
[8] What is the principal ore of aluminium?
A.
Dolomite
B.
Copper
C.
Lignite
D.
Bauxite
Ans:
Bauxite
Explanation :
Bacodte is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.
[9] Which gas is used as fire extinguisher?
A.
Carbon dioxide
B.
Carbon monoxide
C.
Carbon suboxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
[8] What is the principal ore of aluminium?
A.
Dolomite
B.
Copper
C.
Lignite
D.
Bauxite
Ans:
Bauxite
Explanation :
Bacodte is an aluminium ore and is the main source of aluminium. This form of rock consists mostly of the minerals gibbsite, boehmite , and diaspore , in a mixture with the two iron oxides goethite and hematite, the clay mineral kaolinite, and small amounts of anatase TiO2. Bauxite was named after the village Les Baux in southern France, where it was first recognised as containing aluminium and named by the French geologist Pierre Berthier in 1821.
[9] Which gas is used as fire extinguisher?
A.
Carbon dioxide
B.
Carbon monoxide
C.
Carbon suboxide
D.
Sulphur dioxide
Ans:
Carbon dioxide
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
A fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire. Cartridge-operated extinguishers contain the expellant gas (usually carbon dioxide) in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent.
[10] The isotope of Uranium used in atomic reactors is –
A.
U^235
B.
U^236
C.
U^237
D.
U^232
Ans:
U^235
Explanation :
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid (water or gas), which runs through turbines that power either ship's propellers or generators. Some produce isotopes for medical and industrial use, and some are run only for research. When a large fissile atomic nucleus such as U235 or U239 absorbs a neutron, it may undergo nuclear fission.
[11] Which one of the following is not a radioactive element?
A.
Uranium
B.
Thorium
C.
Radium
D.
Cadmium
Ans:
Cadmium
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay. Among uranium, thorium, radium and cadmium the first three does show radioactive properties while the fourth one does not show any kind of radioactive properties.
[12] The anode in a dry cell consists of –
A.
Copper
B.
Zinc
C.
Cadmium
D.
Graphite
Ans:
Zinc
Explanation :
A "dry-cell" battery is essentially comprised of a metal electrode or graphite rod (elemental carbon) surrounded by a moist electrolyte paste enclosed in a metal cylinder. The cathode is composed of a form of elemental carbon called graphite, which serves as a solid support for the reduction half- reaction. A thin zinc cylinder serves as the anode and it undergoes oxidation.
[13] Aspirin is common name of –
A.
Salicylic Acid
B.
Salicylate
C.
Methyl Salicylate
D.
Acetyl Salicylic Acid
Ans:
Acetyl Salicylic Acid
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Aspirin (USAN), also known as acetylsalicylic acid, is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin was first isolated by Felix Hoffmann, a chemist with the German company Bayer in 1897. Aspirin also has an antiplatelet effect by inhibiting the production of thromboxane, which under normal circumstances binds platelet molecules together to create a patch over damaged walls of blood vessels.
[14] Carbon monoxide is an inflammable gas. Which one of the following is also inflammable?
A.
Helium
B.
Nitrogen
C.
Oxygen
D.
Hydrogen
Ans:
Hydrogen
Explanation :
At standard temperature and pressure, hydrogen is a colourless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic has with the molecular formula H2. Naturally occurring atomic hydrogen is rare on Earth because hydrogen readily forms covalent compounds with most elements and is present in the water molecule and in most organic compounds. Hydrogen plays a particularly important role in acid-base chemistry with many reactions exchanging protons between soluble molecules.
[15] The constituents of automobile exhaust that can cause cancer is/are :
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Polycyclic hydrocarbons
D.
Lead
Ans:
Carbon monoxide
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. In the past, when lead was added to gasoline, breathing automobile exhaust was the major source of lead exposure for most people. Lead in the exhaust also contaminated the soil near roads. Another major source a exposure is old paint that contains lead. Lead has been found to be carcinogen. A substance that causes cancer or helps cancer grow is called a carcinogen.
[16] Hard steel contains –
A.
2 to 5 per cent carbon
B.
0.5 to 1.5 per cent carbon
C.
0.1 to 0.4 per cent carbon
D.
0.01 to 0.04 per cent carbon
Ans:
0.5 to 1.5 per cent carbon
Explanation :
The term hardened steel is often used for a medium or high carbon steel that has been given the heat treatments of quenching followed by tempering. The quenching results in the formation of metastable marten site, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as tools and machine parts,. In contrast, the same steel composition in annealed state will be softer as required for forming and machining.
[17] The metals commonly used for electroplating are –
A.
Gold, Sodium and Chromium
B.
Chromium, Copper and Nickel
C.
Nickel, Lead and Chromium
D.
Gold, Sodium and Potassium
Ans:
Chromium, Copper and Nickel
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
The process of electroplating takes place as metals in ionic form move from a positive to negative electrode. An electric current passing through the solution causes objects at the cathode or work piece to be coated by the metal in the solution. Electroplating is done for many reasons, usually to beautify, insulate or to protect and to increase the corrosion resistance, conductivity solder ability of m etal objects. Plating protects by one of two ways, either sacrificially or mechanically.
[18] Which of the following in auto-mobile exhaust can cause cancer?
A.
Oxides of nitrogen
B.
Carbon monoxide
C.
Lead
D.
Polyclinic hydrocarbons
Ans:
Carbon monoxide
Explanation :
Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion. Domestic wood burning and road traffic are the major sources of PAHs. Exposure to PAH-containing substances increases the risk of cancer in humans. The carcinogenicity of PAHs is associated with the complexity of the molecule, i.e., increasing number of benzenoid 'rings, and with metabolic activation to reactive diol epoxide intermediates and their subsequent covalent binding to critical targets in DNA.
[19] Which one of the following gases has the highest calorific value?
A.
Natural gas
B.
Water gas
C.
Coal gas
D.
Indane gas
Ans:
Indane gas
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
The basic calorific value for solid and liquid fuels is the gross calorific value at constant volume and for gaseous fuels it is the gross calorific value at constant pressure. The calorific value in Kcal/Kg: Coal: 4000-700Q; Natural gas: 8600; Coal gas: 4000; Water gas: 4600-4800; and LPG (liquefied petroleum gas such as Indane): 11,900 Kcal/Kg.
[20] Which type of radiations are absorbed by the upper layer of the atmosphere?
A.
Radio-waves
B.
Infrared
C.
Visible
D.
Ultraviolet
Ans:
Ultraviolet
Explanation :
The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's harmful ultraviolet rays. Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
[21] The gas which is mainly responsible for the green house effect is:
A.
Ozone
B.
Oxygen
C.
Carbon dioxide
D.
Carbon monoxide
Ans:
Carbon dioxide
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
[22] Which one of the following is used for dating very old objects of archaeological importance?
A.
Phosphorus-31
B.
Tritium
C.
Radium
D.
Carbon-14
Ans:
Carbon-14
Explanation :
Radiocarbon dating (usually referred to as simply carbon dating) is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 (140 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. After plants die or they are consumed by other organisms (for example, by humans or other animals), the incorporation of all carbon isotopes, including 14C, stops. Thereafter, the concentration (fraction) of 14C declines at a fixed exponential rate due to the radioactive decay of14C.
[23] Which one out of the following helps in burning?
A.
carbon dioxide
B.
oxygen
C.
carbon monoxide
D.
nitrogen
Ans:
oxygen
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
Oxygen is the gas that helps / supports combustion (burning). Nitrogen itself does not support burning (though it forms nitrides with some metals). So, air also supports burning.
[24] Name the gas which is used in balloons in the place of hydrogen?
A.
nitrogen
B.
helium
C.
neorn
D.
argon
Ans:
helium
Explanation :
Helium is used in balloons in the place of hydrogen. This is because hydrogen is a combustible gas and when burst can cause skin burns.
[25] The temperature at which both the Fahrenheit and Centigrade scales have the same value is –
A.
-60°
B.
-40°
C.
-20°
D.
0°
Ans:
-40°
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.
Explanation :
The temperature when both the Celsius and Fahrenheit scales are the same is -40 degrees.