[1] Glass is mainly composed of -
A.
Sodium silicate
B.
Calcium carbonate
C.
Calcium hydroxide
D.
Sodium bicarbonate
Ans:
Sodium silicate
Explanation :
The main constituent of glass is silica ans calcium carbonate is additionally used to give stability and consistency where limestone is added to act as stabilizer and to increase the hardness.
[2] Which of the following is essential for the synthesis of thyroxin?
A.
Potassium
B.
Sodium
C.
Calcium
D.
Iodine
Ans:
Iodine
Explanation :
Iodine is essential for the synthesis of Thyroxine, one of the two major hormones secreted by the thyroid gland. Thyroxine is formed by the molecular addition of iodine to the amino acid tyrosine while the latter is bound to the protein thyroglobulin.
[3] Which of the following processes is used for the production of Biodiesel?
A.
Transamination
B.
Transcription
C.
Transesterification
D.
Translation
Ans:
Transesterification
Explanation :
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions trans-esterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or ethanol).
[4] A matured mammalian cell without nucleus is –
A.
Lymphocyte
B.
Erythrocyte
C.
Spermatozoan
D.
Oocyte
Ans:
Erythrocyte
Explanation :
Mammalian erythrocytes are unique among the vertebrates as they are non-nucleated cells in their mature form. These cells have nuclei during early phases of erythropoiesis, but extrude them during development as they mature in order to provide more space for hemoglobin. In mammals, erythrocytes also lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum.
[5] The most common cause of pollution of air is –
A.
Carbon dioxide
B.
Carbon monoxide
C.
Sulphur dioxide
D.
Smoke
Ans:
Sulphur dioxide
Explanation :
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. It is linked with a number of adverse effects on the respiratory system.
[6] The main source of carbon monoxide is -
A.
Industrial process
B.
Fuel combustion
C.
Transportation
D.
Solid waste disposal
Ans:
Transportation
Explanation :
The main source of carbon monoxide is burning of fossil fuel
[7] Tooth enamel is the hardest substance found in the human body. What is it made up of -
A.
Calcium carbonate
B.
Limestone
C.
Calcium phosphate
D.
Calcium fluoride
Ans:
Calcium phosphate
Explanation :
The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds.
[8] A solution turns blue litmus red, its pH is likely to be -
A.
11
B.
9
C.
5
D.
10
Ans:
5
Explanation :
If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base.
[9] Which of the following metals is used in Space Crafts to withstand high temperatures?
A.
Fe
B.
11
C.
Ni
D.
Pb
Ans:
11
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
The main constituent of glass is silica ans calcium carbonate is additionally used to give stability and consistency where limestone is added to act as stabilizer and to increase the hardness.
[2] Which of the following is essential for the synthesis of thyroxin?
A.
Potassium
B.
Sodium
C.
Calcium
D.
Iodine
Ans:
Iodine
Explanation :
Iodine is essential for the synthesis of Thyroxine, one of the two major hormones secreted by the thyroid gland. Thyroxine is formed by the molecular addition of iodine to the amino acid tyrosine while the latter is bound to the protein thyroglobulin.
[3] Which of the following processes is used for the production of Biodiesel?
A.
Transamination
B.
Transcription
C.
Transesterification
D.
Translation
Ans:
Transesterification
Explanation :
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions trans-esterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or ethanol).
[4] A matured mammalian cell without nucleus is –
A.
Lymphocyte
B.
Erythrocyte
C.
Spermatozoan
D.
Oocyte
Ans:
Erythrocyte
Explanation :
Mammalian erythrocytes are unique among the vertebrates as they are non-nucleated cells in their mature form. These cells have nuclei during early phases of erythropoiesis, but extrude them during development as they mature in order to provide more space for hemoglobin. In mammals, erythrocytes also lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum.
[5] The most common cause of pollution of air is –
A.
Carbon dioxide
B.
Carbon monoxide
C.
Sulphur dioxide
D.
Smoke
Ans:
Sulphur dioxide
Explanation :
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. It is linked with a number of adverse effects on the respiratory system.
[6] The main source of carbon monoxide is -
A.
Industrial process
B.
Fuel combustion
C.
Transportation
D.
Solid waste disposal
Ans:
Transportation
Explanation :
The main source of carbon monoxide is burning of fossil fuel
[7] Tooth enamel is the hardest substance found in the human body. What is it made up of -
A.
Calcium carbonate
B.
Limestone
C.
Calcium phosphate
D.
Calcium fluoride
Ans:
Calcium phosphate
Explanation :
The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds.
[8] A solution turns blue litmus red, its pH is likely to be -
A.
11
B.
9
C.
5
D.
10
Ans:
5
Explanation :
If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base.
[9] Which of the following metals is used in Space Crafts to withstand high temperatures?
A.
Fe
B.
11
C.
Ni
D.
Pb
Ans:
11
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions trans-esterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols (typically methanol or ethanol).
[4] A matured mammalian cell without nucleus is –
A.
Lymphocyte
B.
Erythrocyte
C.
Spermatozoan
D.
Oocyte
Ans:
Erythrocyte
Explanation :
Mammalian erythrocytes are unique among the vertebrates as they are non-nucleated cells in their mature form. These cells have nuclei during early phases of erythropoiesis, but extrude them during development as they mature in order to provide more space for hemoglobin. In mammals, erythrocytes also lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum.
[5] The most common cause of pollution of air is –
A.
Carbon dioxide
B.
Carbon monoxide
C.
Sulphur dioxide
D.
Smoke
Ans:
Sulphur dioxide
Explanation :
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. It is linked with a number of adverse effects on the respiratory system.
[6] The main source of carbon monoxide is -
A.
Industrial process
B.
Fuel combustion
C.
Transportation
D.
Solid waste disposal
Ans:
Transportation
Explanation :
The main source of carbon monoxide is burning of fossil fuel
[7] Tooth enamel is the hardest substance found in the human body. What is it made up of -
A.
Calcium carbonate
B.
Limestone
C.
Calcium phosphate
D.
Calcium fluoride
Ans:
Calcium phosphate
Explanation :
The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds.
[8] A solution turns blue litmus red, its pH is likely to be -
A.
11
B.
9
C.
5
D.
10
Ans:
5
Explanation :
If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base.
[9] Which of the following metals is used in Space Crafts to withstand high temperatures?
A.
Fe
B.
11
C.
Ni
D.
Pb
Ans:
11
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and other industrial facilities (20%). Smaller sources of SO2 emissions include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. It is linked with a number of adverse effects on the respiratory system.
[6] The main source of carbon monoxide is -
A.
Industrial process
B.
Fuel combustion
C.
Transportation
D.
Solid waste disposal
Ans:
Transportation
Explanation :
The main source of carbon monoxide is burning of fossil fuel
[7] Tooth enamel is the hardest substance found in the human body. What is it made up of -
A.
Calcium carbonate
B.
Limestone
C.
Calcium phosphate
D.
Calcium fluoride
Ans:
Calcium phosphate
Explanation :
The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds.
[8] A solution turns blue litmus red, its pH is likely to be -
A.
11
B.
9
C.
5
D.
10
Ans:
5
Explanation :
If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base.
[9] Which of the following metals is used in Space Crafts to withstand high temperatures?
A.
Fe
B.
11
C.
Ni
D.
Pb
Ans:
11
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
The protective layer around your teeth, called enamel, is the strongest substance that our body produces. In fact, tooth enamel is stronger than any other substance on earth except for diamonds.
[8] A solution turns blue litmus red, its pH is likely to be -
A.
11
B.
9
C.
5
D.
10
Ans:
5
Explanation :
If the litmus paper turns red, it indicates the presence of an acid while if it turns blue, it indicates the presence of a base.
[9] Which of the following metals is used in Space Crafts to withstand high temperatures?
A.
Fe
B.
11
C.
Ni
D.
Pb
Ans:
11
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Titanium alloy, which has high corrosion resistance, high specific strength, and good heat resistance, is used for different spacecraft parts including outer fuel tank sheathing and wings. It is extremely strong at high temperatures.
[10] Brass gets discoloured in air due to constant exposure in presence of:
A.
Aluminium phosphide
B.
Hydrogen sulphide
C.
Hydrogenated wafers
D.
Aluminium sulphide
Ans:
Hydrogen sulphide
Explanation :
Brass gets discoloured in air because of Hydrogen sulphide. Transition elements are coloured. The brass is combination of Zn and Cu. But it is discoloured due to hydrogen sulphide in air.
[11] Neutrons are slowed down in a nuclear reactor by –
A.
Fissionable Material
B.
Moderator
C.
Control rods
D.
Cooling system
Ans:
Moderator
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
In thermal nuclear reactors, the coolant acts as a moderator that must slow down the neutrons before they can be efficiently absorbed by the fuel. It allows neutrons to slow down to energies where they can easily cause a nucleus to fission.
[12] An element of atomic no. 29 belongs to –
A.
s-block
B.
d-block
C.
p-block
D.
f-block
Ans:
d-block
Explanation :
Copper (Cu) has the atomic number of 29. Copper belongs to the d-block which is the collective name for Groups 3 to 12 in the periodic table. Most of the d-block elements are considered to be metals, with a common lustrous metallic appearance.
[13] Mechanical energy is the combination of kinetic energy and .
A.
Heat energy
B.
Chemical energy
C.
Potential energy
D.
Nuclear energy
Ans:
Potential energy
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Mechanical energy is the energy possessed by an object due to either its motion or its stored energy of position. The total amount of mechanical energy is merely the sum of potential energy and kinetic energy.
[14] Magnetism at the centre of a bar magnet is -
A.
minimum
B.
maximum
C.
zero
D.
minimum or maximum
Ans:
zero
Explanation :
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Anywhere else they are slightly divergent.
[15] Substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected are called -
A.
Catalysts
B.
Hydrocarbons
C.
Oxidising agents
D.
Substitutes
Ans:
Catalysts
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Catalysts are substances that cause a reaction to occur or proceed at a different rate without the reaction itself being affected. Eg: hydrogenation of vegetable oils using a nickel catalyst.
[16] Which one of the following elements exhibits the greatest tendency to lose electrons?
A.
Fluorine
B.
Lithium
C.
Oxygen
D.
Zine
Ans:
Lithium
Explanation :
Alkali metals such as Lithium are the most electropositive elements in the periodic table. As alkali metals have low ionization energies, they have a great tendency to lose electrons forming unipositive ions.
[17] Poison used for killing rats is –
A.
Calcium phosphide (Ca3P2)
B.
Zinc phosphide (Zn3P2)
C.
Magnesium nitride (Mg3N2)
D.
Magnesium phosphide (Mg3P2)
Ans:
Zinc phosphide (Zn3P2)
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Zinc phosphide is an inorganic compound that is used in pesticide products as a rodenticide. Formulated as attractive bait, it releases phosphine gas once it is exposed to acid and moisture in the stomach. The phosphine gas is very toxic to all animals.
[18] The commonly used safety fuse-wire is made of -
A.
an alloy of Nickel and Lead
B.
an alloy of Tin and Lead
C.
an alloy of Tin and Nickel
D.
an alloy of Lead and Iron
Ans:
an alloy of Tin and Lead
Explanation :
As a rule, fuse elements of time delay fuses contain low melting point materials, e.g. tin (Sn) or zinc (Zn) and alloys thereof.
[19] Lead pencil contains -
A.
Lead nitrate
B.
Graphite
C.
Lead peroxide
D.
Lead Sulphate
Ans:
Graphite
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.
[20] The most suitable unit for expressing nuclear radius is -
A.
nanometre
B.
fermi
C.
angstrom
D.
micron
Ans:
fermi
Explanation :
The atomic radius is a measure of the size of an atom. It is defined as one half the distance between the nuclei of two identical atoms that are bonded together. Angstrom is the most common unit used for measuring atomic radius.
[21] The catalyst used in hydrogenation of oils is -
A.
Fe
B.
V2O5
C.
Ni
D.
O2
Ans:
Ni
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
The catalyst used in hydrogenation of oils is nickel. It is used to speed up the reaction. Vegetable oils convert into vanaspati after hydrogenation.
[22] What is used in storage batteries?
A.
Copper
B.
Tin
C.
Lead
D.
Zinc
Ans:
Lead
Explanation :
The electrodes of the cells in a storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide (PbO2). Dilute sulfuric acid (H2SO4) serves as the electrolyte. Lead-acid batteries, also known as lead' storage batteries, can store a lot of charge and provide high current for short periods of time.
[23] The biogas used for cooking is a mixture of which of the following?
A.
Carbon dioxide and oxygen
B.
Isobutane and propane
C.
Methane and Carbon monoxide
D.
Methane and carbon dioxide
Ans:
Methane and carbon dioxide
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Biogas is essentially a mixture of Methane (CH4, around 55-75%) but also contains Carbon Dioxide (CO3), around 25-30%), varying quantities of Water (H2O) and Hydrogen Sulphide (H2S). Other compounds can also be found, especially in waste dump biogas: Ammonia (NH3), Hydrogen (H2), Nitrogen (N2) and Carbon Monoxide (CO). Methane is the valuable component under the aspect of using biogas fuel.
[24] Ozone saves the biosphere by absorbing high energy radiations called -
A.
Infra-red
B.
Gamma rays
C.
Ultraviolet rays (UV)
D.
X-rays
Ans:
Ultraviolet rays (UV)
Explanation :
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It absorbs 97 to 99 percent of the Suns medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which otherwise would potentially damage exposed life forms near the surface.
[25] Silica gel is a -
A.
moisturizer
B.
flavouring agent
C.
drying agent
D.
delicious food
Ans:
drying agent
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.
Explanation :
Silica gel is a drying agent, meant to remove moisture from an enclosed space. It is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel packs are found in boxes containing electronics or new shoes and inside purses or medicine bottles. The packets contain either granular silicic acid, which resembles sand, or tiny gel beads.