[1] Which of the following is a super-cooled liquid?
A.
Ice-cream
B.
Ammonia
C.
Glass
D.
Wood
Ans:
Glass
Explanation :
Most of us think as glass as a solid material, but it is actually a super cooled liquid. Molecular units have a disordered arrangement yet still have sufficient cohesion that mechanical rigidity is produced. Glass was first made in the Middle East, approximately during the third millennium BC. Early uses were primarily for vessels or decoration. Glass did not come into use for windows until the first century AD, and was made at that time by casting or hand blowing the glass. Today, glass is a highly engineered material with many different varieties and countless uses. There is float glass, annealed glass, wired glass, tempered glass, safety or laminated glass, leaded glass, heat absorbing glass, low e glass, etc. Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid.
[2] Soap is prepared by boiling caustic soda with –
A.
Alcohol
B.
Kerosene oil
C.
Glycerine
D.
Fats
Ans:
Fats
Explanation :
The most basic kind of soap is made from cuastic soda and animal fat. The two are heated together, and then cooled. The process is called "saponification". In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglyeerides which are esters of fatty acids, to form the sodium salt, of a carboxylate.
[3] Bronze is an alloy of –
A.
Copper and Zinc
B.
Tin and Zinc
C.
Copper and Tin
D.
Iron and Zinc
Ans:
Copper and Tin
Explanation :
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and tough, and it was particularly significant in antiquity, so much that the Bronze Age was named after the metal. However, historical pieces were often made interchangeably of bronzes or brasses with different compositions, so modern museum and scholarly descriptions of older objects increasingly use the more inclusive term "copper alloy" instead. Historically the term latten was used for such alloys.
[4] Which of the following elements is non-radioactive?
A.
Uranium
B.
Thorium
C.
Plutonium
D.
Zirconium
Ans:
Zirconium
Explanation :
Zirconium is non-radioactive. It is a chemical element with the symbol Zr, atomic number 40 and atomic mass of 91.224. The name of zirconium is taken from the mineral zircon, the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that resembles titanium.
[5] The gas used for artificial fruit ripening of green fruit is –
A.
Ethylene
B.
Acetylene
C.
Ethane
D.
Methane
Ans:
Ethylene
Explanation :
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.
[6] Manganite is an ore/mineral of .
A.
Beryllium
B.
Chromium
C.
Manganese
D.
Copper
Ans:
Manganese
Explanation :
Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic). Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles.
[7] The presence of which of the following salts in water causes corrosion in steam boilers?
A.
Sodium Chloride
B.
Magnesium Chloride
C.
Calcium bicarbonate
D.
Potassium bicarbonate
Ans:
Magnesium Chloride
Explanation :
Magnesium chloride is the name for the chemical compound with the formula MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water.
[8] The freezing point of fresh water is -
A.
0°C
B.
4°C
C.
3°C
D.
5 C
Ans:
0°C
Explanation :
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
[9] is used for making vinegar.
A.
Tartaric acid
B.
Malic acid
C.
Oxalic acid
D.
Acetic acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Most of us think as glass as a solid material, but it is actually a super cooled liquid. Molecular units have a disordered arrangement yet still have sufficient cohesion that mechanical rigidity is produced. Glass was first made in the Middle East, approximately during the third millennium BC. Early uses were primarily for vessels or decoration. Glass did not come into use for windows until the first century AD, and was made at that time by casting or hand blowing the glass. Today, glass is a highly engineered material with many different varieties and countless uses. There is float glass, annealed glass, wired glass, tempered glass, safety or laminated glass, leaded glass, heat absorbing glass, low e glass, etc. Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid.
[2] Soap is prepared by boiling caustic soda with –
A.
Alcohol
B.
Kerosene oil
C.
Glycerine
D.
Fats
Ans:
Fats
Explanation :
The most basic kind of soap is made from cuastic soda and animal fat. The two are heated together, and then cooled. The process is called "saponification". In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglyeerides which are esters of fatty acids, to form the sodium salt, of a carboxylate.
[3] Bronze is an alloy of –
A.
Copper and Zinc
B.
Tin and Zinc
C.
Copper and Tin
D.
Iron and Zinc
Ans:
Copper and Tin
Explanation :
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and tough, and it was particularly significant in antiquity, so much that the Bronze Age was named after the metal. However, historical pieces were often made interchangeably of bronzes or brasses with different compositions, so modern museum and scholarly descriptions of older objects increasingly use the more inclusive term "copper alloy" instead. Historically the term latten was used for such alloys.
[4] Which of the following elements is non-radioactive?
A.
Uranium
B.
Thorium
C.
Plutonium
D.
Zirconium
Ans:
Zirconium
Explanation :
Zirconium is non-radioactive. It is a chemical element with the symbol Zr, atomic number 40 and atomic mass of 91.224. The name of zirconium is taken from the mineral zircon, the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that resembles titanium.
[5] The gas used for artificial fruit ripening of green fruit is –
A.
Ethylene
B.
Acetylene
C.
Ethane
D.
Methane
Ans:
Ethylene
Explanation :
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.
[6] Manganite is an ore/mineral of .
A.
Beryllium
B.
Chromium
C.
Manganese
D.
Copper
Ans:
Manganese
Explanation :
Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic). Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles.
[7] The presence of which of the following salts in water causes corrosion in steam boilers?
A.
Sodium Chloride
B.
Magnesium Chloride
C.
Calcium bicarbonate
D.
Potassium bicarbonate
Ans:
Magnesium Chloride
Explanation :
Magnesium chloride is the name for the chemical compound with the formula MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water.
[8] The freezing point of fresh water is -
A.
0°C
B.
4°C
C.
3°C
D.
5 C
Ans:
0°C
Explanation :
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
[9] is used for making vinegar.
A.
Tartaric acid
B.
Malic acid
C.
Oxalic acid
D.
Acetic acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and tough, and it was particularly significant in antiquity, so much that the Bronze Age was named after the metal. However, historical pieces were often made interchangeably of bronzes or brasses with different compositions, so modern museum and scholarly descriptions of older objects increasingly use the more inclusive term "copper alloy" instead. Historically the term latten was used for such alloys.
[4] Which of the following elements is non-radioactive?
A.
Uranium
B.
Thorium
C.
Plutonium
D.
Zirconium
Ans:
Zirconium
Explanation :
Zirconium is non-radioactive. It is a chemical element with the symbol Zr, atomic number 40 and atomic mass of 91.224. The name of zirconium is taken from the mineral zircon, the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that resembles titanium.
[5] The gas used for artificial fruit ripening of green fruit is –
A.
Ethylene
B.
Acetylene
C.
Ethane
D.
Methane
Ans:
Ethylene
Explanation :
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.
[6] Manganite is an ore/mineral of .
A.
Beryllium
B.
Chromium
C.
Manganese
D.
Copper
Ans:
Manganese
Explanation :
Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic). Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles.
[7] The presence of which of the following salts in water causes corrosion in steam boilers?
A.
Sodium Chloride
B.
Magnesium Chloride
C.
Calcium bicarbonate
D.
Potassium bicarbonate
Ans:
Magnesium Chloride
Explanation :
Magnesium chloride is the name for the chemical compound with the formula MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water.
[8] The freezing point of fresh water is -
A.
0°C
B.
4°C
C.
3°C
D.
5 C
Ans:
0°C
Explanation :
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
[9] is used for making vinegar.
A.
Tartaric acid
B.
Malic acid
C.
Oxalic acid
D.
Acetic acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.
[6] Manganite is an ore/mineral of .
A.
Beryllium
B.
Chromium
C.
Manganese
D.
Copper
Ans:
Manganese
Explanation :
Manganite is a mineral composed of manganese oxide-hydroxide, MnO(OH), crystallizing in the monoclinic system (pseudo-orthorhombic). Crystals of manganite are prismatic and deeply striated parallel to their length; they are often grouped together in bundles.
[7] The presence of which of the following salts in water causes corrosion in steam boilers?
A.
Sodium Chloride
B.
Magnesium Chloride
C.
Calcium bicarbonate
D.
Potassium bicarbonate
Ans:
Magnesium Chloride
Explanation :
Magnesium chloride is the name for the chemical compound with the formula MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water.
[8] The freezing point of fresh water is -
A.
0°C
B.
4°C
C.
3°C
D.
5 C
Ans:
0°C
Explanation :
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
[9] is used for making vinegar.
A.
Tartaric acid
B.
Malic acid
C.
Oxalic acid
D.
Acetic acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Magnesium chloride is the name for the chemical compound with the formula MgCl2 and its various hydrates MgCl2(H2O)x. These salts are typical ionic halides, being highly soluble in water.
[8] The freezing point of fresh water is -
A.
0°C
B.
4°C
C.
3°C
D.
5 C
Ans:
0°C
Explanation :
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
[9] is used for making vinegar.
A.
Tartaric acid
B.
Malic acid
C.
Oxalic acid
D.
Acetic acid
Ans:
Acetic acid
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and water. The acetic acid is produced by the fermentation of ethanol by acetic acid bacteria. It is mainly used as a cooking ingredient.
[10] Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
A.
Scandium
B.
Gallium
C.
Titanium
D.
Germanium
Ans:
Gallium
Explanation :
0
[11] The most reactive among the halogens is -
A.
Fluorine
B.
Chlorine
C.
Bromine
D.
Iodine
Ans:
Fluorine
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. All halogens form Group 1 salts with similar properties.
[12] Which one of the following organic compounds has fruity smell?
A.
Alcohol
B.
Aldehyde
C.
Ester
D.
Ether
Ans:
Ester
Explanation :
Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and flavor industry. Ester bonds are also found in many polymers. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are widespread in nature and are widely used in industry.
[13] What material is used to make electric heater coil?
A.
Copper
B.
Iron
C.
Silver
D.
Nichrome
Ans:
Nichrome
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. It is silvery-grey in colour, is corrosion-resistant, and has a high melting point of about 1400 degree C (2552 degree F).
[14] Which one of the following is a major green gas?
A.
Carbon dioxide
B.
Chloro fluorocarbon
C.
Carbon monoxide
D.
Freon
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. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects.
[15] Pasteurisation is the process in which milk is heated to –
A.
60°C for 10 minutes
B.
63° C for 20 minutes
C.
63°C for 30 minutes
D.
72°C for 10 minutes
Ans:
63°C for 30 minutes
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Pasteurization for pasteurisation is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
[16] What is the maximum Water Vapour content in the atmosphere?
A.
2 to 3 per cent
B.
3 to 4 per cent
C.
4 to 5 per cent
D.
5 to 6 per cent
Ans:
3 to 4 per cent
Explanation :
The atmosphere of Earth is a layer of gases surrounding the planet. Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Air is the name given to the atmosphere used in breathing and photosynthesis. Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.
[17] Steel contains –
A.
0.1 - 2% carbon
B.
5 - 10% carbon
C.
more than 10% carbon
D.
no carbon
Ans:
0.1 - 2% carbon
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Other alloying elements sometimes used are manganese, chromium, vanadium and tungsten. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another.
[18] The chemicals most commonly used for cloud seeding or artificial rainmaking' is/are –
A.
Silver Iodide
B.
Sodium Chloride
C.
Dry ice or frozen carbon dioxide
D.
All the above
Ans:
Silver Iodide
Explanation :
Cloud seeding, a form of intentional weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports. The most common chemicals used for cloud seeding include silver iodide and dry ice (solid carbon dioxide).
[19] The Refrigerant 'FREON' is –
A.
Calcium Tetra Fluoride
B.
Difluoro Dichloro Methane
C.
Fluorspar and Felspar
D.
Hydrofluosilicic Acid
Ans:
Difluoro Dichloro Methane
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Dichlorodifluoromethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 due to concerns about damage to the ozone layer. It is soluble in many organic solvents. It can be prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. This reaction can also produce trichlorofluoromethane (CCl3F), chlorotrifluoromethane (CClF3) and tetrafluoromethane (CF4).
[20] is the number of shells for elements of the 3rd period.
A.
2
B.
1
C.
0
D.
3
Ans:
0
Explanation :
The third period of the periodic table consists of the elements whose atoms has three shells occupied by electrons in its Ground State (when it is not excited or in a reaction).
[21] Which one among the following polymers is used for making bullet-proof material?
A.
Polyvinyl chloride
B.
Polystyrene
C.
Polyethylene
D.
Polyamide
Ans:
Polyethylene
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
[22] The nucleus of an atom consists of -
A.
electrons and neutrons
B.
electrons and protons
C.
protons and neutrons
D.
All of the above
Ans:
protons and neutrons
Explanation :
The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks.
[23] The isotope of Uranium capable of sustaining chain reaction is -
A.
U-235
B.
U-238
C.
U-239
D.
N.O.T.
Ans:
U-235
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table.
[24] Conversion of chemical energy into electrical energy occurs in -
A.
Atomic bombs
B.
Dynamo
C.
A battery
D.
Electric heaters
Ans:
A battery
Explanation :
A battery is a form of chemical energy that can be converted to electrical energy. It is a device consisting of one or more electrochemical cells which performs this action. The first battery (or "voltaic pile") was invented in 1800 by Alessandro Volta.
[25] The fuel that is used in modern submarines is –
A.
Nuclear fuel
B.
Petrol
C.
Coal
D.
Diesel
Ans:
Nuclear fuel
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Explanation :
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.