[1] Solder is an alloy of –
A.
lead, zinc
B.
copper, lead
C.
tin, lead
D.
sodium, lead
Ans:
tin, lead
Explanation :
Tin/lead solders, also called soft solders, are commercially available with tin concentrations between 5% and 70% by weight. The greater the tin concentration, the greater the solder's tensile and shear strengths. Alloys commonly used for electrical soldering are 60/40 Tin/lead (Sn/Pb) which melts at 370 °F or 188 °C and 63/37 Sn/Pb used principally in electrical/electronic work.
[2] What is the most common salt in sea water?
A.
Calcium carbonate
B.
Potassium chloride
C.
Sodium chloride
D.
Magnesium sulphate
Ans:
Sodium chloride
Explanation :
Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the formula NaCl, representing equal proportions of sodium and chloride. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multi-cellular organisms.
[3] When quick lime is added to water
A.
heat is liberated
B.
heat is absorbed
C.
temperature decreases
D.
no heat change takes place
Ans:
heat is liberated
Explanation :
When quick lime is added to water, then a chemical reaction takes places and slaked lime is formed, evolving heat in this process. It makes the water boil.
[4] The number of neutrons present in an element having mass number 226 and atomic number 88 is–
A.
88
B.
138
C.
314
D.
50
Ans:
138
Explanation :
The mass number is a count of the number of particles in an atom's nucleus which is made up of protons and neutrons. In other words, Mass Number = Number of Protons + Number of Neutrons. The atomic number is the number of protons in an atom of an element, 226 = 88 + number of Neutrons. So, the number of neutrons= 226 - 88= 138.
[5] The atomic number of hydrogen is 1. This implies that it contains in its K-shell.
A.
One neutron
B.
One proton
C.
One electron
D.
None of the above
Ans:
One electron
Explanation :
This implies that Hydrogen has one electron in its K shell. Also, it requires one more electron to fill the K shell. So two hydrogen atoms share their electrons to form a molecule of hydrogen, H2.
[6] Name two elements that find wide application in transistor industry –
A.
Silicon and Germanium
B.
Carbon and Platinum
C.
Iridium and Germanium
D.
Tungsten and Platinum
Ans:
Silicon and Germanium
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium arsenide (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.
[7] The energy of the sun is mainly due to -
A.
nuclear fission
B.
radioactivity
C.
heat
D.
nuclear fusion
Ans:
nuclear fusion
Explanation :
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.
[8] Tear gas used by the police to disperse the mob contains -
A.
Carbon dioxide
B.
Chlorine
C.
Ammonia
D.
Hydrogen sulphide
Ans:
Chlorine
Explanation :
Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness.
[9] Epsom salt is used -
A.
as purgative
B.
in softening water
C.
in paper industry
D.
in making tooth paste
Ans:
as purgative
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Tin/lead solders, also called soft solders, are commercially available with tin concentrations between 5% and 70% by weight. The greater the tin concentration, the greater the solder's tensile and shear strengths. Alloys commonly used for electrical soldering are 60/40 Tin/lead (Sn/Pb) which melts at 370 °F or 188 °C and 63/37 Sn/Pb used principally in electrical/electronic work.
[2] What is the most common salt in sea water?
A.
Calcium carbonate
B.
Potassium chloride
C.
Sodium chloride
D.
Magnesium sulphate
Ans:
Sodium chloride
Explanation :
Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the formula NaCl, representing equal proportions of sodium and chloride. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multi-cellular organisms.
[3] When quick lime is added to water
A.
heat is liberated
B.
heat is absorbed
C.
temperature decreases
D.
no heat change takes place
Ans:
heat is liberated
Explanation :
When quick lime is added to water, then a chemical reaction takes places and slaked lime is formed, evolving heat in this process. It makes the water boil.
[4] The number of neutrons present in an element having mass number 226 and atomic number 88 is–
A.
88
B.
138
C.
314
D.
50
Ans:
138
Explanation :
The mass number is a count of the number of particles in an atom's nucleus which is made up of protons and neutrons. In other words, Mass Number = Number of Protons + Number of Neutrons. The atomic number is the number of protons in an atom of an element, 226 = 88 + number of Neutrons. So, the number of neutrons= 226 - 88= 138.
[5] The atomic number of hydrogen is 1. This implies that it contains in its K-shell.
A.
One neutron
B.
One proton
C.
One electron
D.
None of the above
Ans:
One electron
Explanation :
This implies that Hydrogen has one electron in its K shell. Also, it requires one more electron to fill the K shell. So two hydrogen atoms share their electrons to form a molecule of hydrogen, H2.
[6] Name two elements that find wide application in transistor industry –
A.
Silicon and Germanium
B.
Carbon and Platinum
C.
Iridium and Germanium
D.
Tungsten and Platinum
Ans:
Silicon and Germanium
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium arsenide (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.
[7] The energy of the sun is mainly due to -
A.
nuclear fission
B.
radioactivity
C.
heat
D.
nuclear fusion
Ans:
nuclear fusion
Explanation :
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.
[8] Tear gas used by the police to disperse the mob contains -
A.
Carbon dioxide
B.
Chlorine
C.
Ammonia
D.
Hydrogen sulphide
Ans:
Chlorine
Explanation :
Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness.
[9] Epsom salt is used -
A.
as purgative
B.
in softening water
C.
in paper industry
D.
in making tooth paste
Ans:
as purgative
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
When quick lime is added to water, then a chemical reaction takes places and slaked lime is formed, evolving heat in this process. It makes the water boil.
[4] The number of neutrons present in an element having mass number 226 and atomic number 88 is–
A.
88
B.
138
C.
314
D.
50
Ans:
138
Explanation :
The mass number is a count of the number of particles in an atom's nucleus which is made up of protons and neutrons. In other words, Mass Number = Number of Protons + Number of Neutrons. The atomic number is the number of protons in an atom of an element, 226 = 88 + number of Neutrons. So, the number of neutrons= 226 - 88= 138.
[5] The atomic number of hydrogen is 1. This implies that it contains in its K-shell.
A.
One neutron
B.
One proton
C.
One electron
D.
None of the above
Ans:
One electron
Explanation :
This implies that Hydrogen has one electron in its K shell. Also, it requires one more electron to fill the K shell. So two hydrogen atoms share their electrons to form a molecule of hydrogen, H2.
[6] Name two elements that find wide application in transistor industry –
A.
Silicon and Germanium
B.
Carbon and Platinum
C.
Iridium and Germanium
D.
Tungsten and Platinum
Ans:
Silicon and Germanium
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium arsenide (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.
[7] The energy of the sun is mainly due to -
A.
nuclear fission
B.
radioactivity
C.
heat
D.
nuclear fusion
Ans:
nuclear fusion
Explanation :
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.
[8] Tear gas used by the police to disperse the mob contains -
A.
Carbon dioxide
B.
Chlorine
C.
Ammonia
D.
Hydrogen sulphide
Ans:
Chlorine
Explanation :
Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness.
[9] Epsom salt is used -
A.
as purgative
B.
in softening water
C.
in paper industry
D.
in making tooth paste
Ans:
as purgative
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
This implies that Hydrogen has one electron in its K shell. Also, it requires one more electron to fill the K shell. So two hydrogen atoms share their electrons to form a molecule of hydrogen, H2.
[6] Name two elements that find wide application in transistor industry –
A.
Silicon and Germanium
B.
Carbon and Platinum
C.
Iridium and Germanium
D.
Tungsten and Platinum
Ans:
Silicon and Germanium
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids germanium (1947) and silicon (1954) — in amorphous, polycrystalline and mono-crystalline form; the compounds gallium arsenide (1966) and silicon carbide (1997), the alloy silicon-germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.
[7] The energy of the sun is mainly due to -
A.
nuclear fission
B.
radioactivity
C.
heat
D.
nuclear fusion
Ans:
nuclear fusion
Explanation :
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.
[8] Tear gas used by the police to disperse the mob contains -
A.
Carbon dioxide
B.
Chlorine
C.
Ammonia
D.
Hydrogen sulphide
Ans:
Chlorine
Explanation :
Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness.
[9] Epsom salt is used -
A.
as purgative
B.
in softening water
C.
in paper industry
D.
in making tooth paste
Ans:
as purgative
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle that even our sun uses.
[8] Tear gas used by the police to disperse the mob contains -
A.
Carbon dioxide
B.
Chlorine
C.
Ammonia
D.
Hydrogen sulphide
Ans:
Chlorine
Explanation :
Tear gas, formally known as a lachrymatory agent, is a possibly lethal chemical weapon that stimulates the corneal nerves in the eyes to cause tears, pain, and even blindness.
[9] Epsom salt is used -
A.
as purgative
B.
in softening water
C.
in paper industry
D.
in making tooth paste
Ans:
as purgative
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen which is commonly called Epsom Salt. Because like other salts, it withdraws water from cells, Epsom salt is used as a fast-acting purgative in some types of poisoning, to draw water into the intestines, thus, reducing constipation; to withdraw toxins from the body; and to draw fluid from the brain in cases of cerebral edema.
[10] The ratio of pure gold in 18 carat gold is -
A.
1
B.
0.8
C.
0.75
D.
0.6
Ans:
0.75
Explanation :
The gold content of alloys is measured in carats (k). Pure gold is designated as 24k where the ratio of pure gold is supposed to be 100 per cent. So 18 k gold will have pure gold ratio of 75 per cent.
[11] Oil of vitriol is -
A.
nitric acid
B.
sulfuric acid
C.
hydrochloric acid
D.
phosphoric acid
Ans:
sulfuric acid
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Sulfuric acid or was called "oil of vitriol" by medieval European alchemists because it was prepared by roasting "green vitriol" in an iron retort.
[12] The number of electrons in the outer shell of the most stable or inert atoms is .
A.
1
B.
5
C.
3
D.
8
Ans:
8
Explanation :
The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
[13] Supersonic jet causes pollution by thinning of -
A.
O3 layer
B.
O2 layer
C.
SO2 layer
D.
CO2 layer
Ans:
O3 layer
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Three forms (or allotropes) of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O or atomic oxygen), oxygen has (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen). Ozone is formed in the stratosphere when oxygen molecules photodissociate after absorbing an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules.
[14] Which type of glass is used for making glass reinforced plastic?
A.
Pyrex glass
B.
Flint glass
C.
Quartz glass
D.
Fibre glass
Ans:
Fibre glass
Explanation :
Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its bulk strength and weight properties are also very favorable when compared to metals, and it can be easily formed using molding processes.
[15] Photoxidation process is initiated by –
A.
light
B.
heat
C.
oxygen
D.
catalyst
Ans:
light
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Oxidation is a process in which something (an atom or molecule or substance) loses an electron to something else. Photo-oxidation is therefore the process of oxidation which is caused by shining light on it. Often, light can be used to cause reactions to happen, such as oxidation. The term "photo" comes from "photon" which is light. The effect is facilitated by radiant energy such as UV or artificial light. This process is the most significant factor in weathering of polymers.
[16] Ultraviolet radiation striking the earth is due to the depletion of –
A.
carbon monoxide
B.
carbon dioxide
C.
ozone
D.
oxygen
Ans:
ozone
Explanation :
Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level.
[17] In nuclear reactors, graphite is used as a/an –
A.
fuel
B.
lubricant
C.
moderator
D.
insulator
Ans:
moderator
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
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. In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235.
[18] Sea water can be purified by the process of –
A.
distillation
B.
evaporation
C.
filtration
D.
fractional distillation
Ans:
distillation
Explanation :
The traditional process used in desalination operations is vacuum distillation—essentially the boiling of water at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.
[19] Which is/ are the important raw materials in cement industry?
A.
Limestone
B.
Gypsum and Clay
C.
Clay
D.
Limestone and Clay
Ans:
Limestone and Clay
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Limestone Claimed Clay Cement is a low-carbon alternative to the standard Portland cement. LC3 can reduce CO2 emissions related to cement manufacturing of cement by reducing the amount of clinker, replacing it with limestone and claimed clays.
[20] The father of modern chemistry is –
A.
Priestley
B.
Lavoisier
C.
Dalton
D.
Mendeleeff
Ans:
Lavoisier
Explanation :
Antoine Lavoisier was a French nobleman and chemist central to the 18th-century chemical revolution and a large influence on both the history of chemistry and the history of biology.
[21] The acid rain destroys vegetations because it contains –
A.
nitric acid
B.
ozone
C.
carbon monoxide
D.
sulphuric acid
Ans:
sulphuric acid
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxides, which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results.
[22] Diamonds are glittering and attractive because light incident on them undergoes –
A.
highest refraction
B.
multiple internal reflections
C.
multiple surface reflections
D.
hundred percent transmission
Ans:
multiple internal reflections
Explanation :
Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency', this results in the clear, colourless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) colour diamond blue (boron), yellow (nitrogen), brown (lattice defects), green (radiation exposure), purple, pink, orange or red.
[23] Which of the following is a supercooled liquid?
A.
Ice Cream
B.
Teflon
C.
Glass
D.
Mercury
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
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.
[24] On heating, Gypsum loses certain percentage of its water content and becomes -
A.
Chalk
B.
Calcium sulphate
C.
Plaster of Paris
D.
a pearl
Ans:
Plaster of Paris
Explanation :
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.
[25] What is the element required for solar energy conversion?
A.
Beryllium
B.
Tantalum
C.
Silicon
D.
Ultra pure carbon
Ans:
Silicon
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.
Explanation :
The most prevalent bulk material for solar cells is crystalline silicon (abbreviated as a group as c-Si), also known as "solar grade silicon". Bulk silicon is separated into multiple categories according to crystallinity and crystal size in the resulting ingot, ribbon, or wafer.