[1] Electric current in a metal wire is due to the flow of —
A.
Electrons
B.
Protons
C.
Ions
D.
Holes
Ans:
Electrons
Explanation :
A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor. The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field.
[2] Which type of reaction produces the most harmful radiation?
A.
Fusion reaction
B.
Fission reaction
C.
Chemical reaction
D.
Photo-Chemical reaction
Ans:
Fission reaction
Explanation :
Radiation is one of the byproducts of radioactive decay of unstable atomic nuclei. Nuclear fission is the process on which the operation of most nuclear power plants is based. When certain nuclei (for example that of uranium-235) are bombarded with neutrons, the nucleus splits into two smaller nuclei of roughly (though not exactly) equal sizes.
[3] Optic fibres are used in :
A.
CAT scans
B.
X-ray photos
C.
Ultrasound scans
D.
Endoscopy
Ans:
Endoscopy
Explanation :
Optical fibres are used in endoscopic instruments that enable doctors to view internal body parts without having to perform surgery. Fernando Alves Martins of Portugal invented the first fiber optic endoscope in 1963-64. Further innovations included using additional fibres to channel light to the objective end from a powerful external source, thereby achieving the high level of full spectrum illumination that was needed for detailed viewing, and colour photography.
[4] Two waves, each of amplitude 1.5 mm and frequency 10 Hz, are travelling in opposite direction with a speed of 20 mm/s. The distance in mm between adjacent nodes is :
A.
1
B.
1.2
C.
1.5
D.
2
Ans:
1
Explanation :
Since the amplitudes, frequency and the speed of both the waves are in same, hence the wavelength of the composite wave will be the same as the single wave.
[5] While catching a ball, a player pulls down his hands to lower the –
A.
force
B.
momentum
C.
impulse
D.
catching time
Ans:
momentum
Explanation :
A cricketer lowers his hands while taking a catch to decrease the rate of momentum. Cricketers increase the time by pulling their hand's backward with the ball while taking a catch. Linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.
[6] A camera uses a to form an image on a piece of film at the back.
A.
convex lens
B.
concave lens
C.
diverging lens
D.
none of these
Ans:
convex lens
Explanation :
A camera consists of three main parts. • The body which is light tight and contains all the mechanical parts. • The lens which is a convex lens. • The film or a charged couple device in the case of a digital camera.
[7] In 1866, John Newlands, an English scientist, arranged the then known elements in the order of increasing atomic masses. He found that every eighth element had properties similar to that of the first. He called it the -
A.
Law of Pentamates
B.
Law of musical notes
C.
Law of Octaves
D.
None of the above
Ans:
Law of Octaves
Explanation :
Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
[8] Which of the following pairs of physical quantities have the same dimensions?
A.
Force and Power
B.
Work and Power
C.
Work and Energy
D.
Momentum and Power
Ans:
Work and Energy
Explanation :
The term energy is used to describe the capacity of a system to do work on another system. Energy of all types (Surface Tension, Kinetic, Potential etc.) have the same dimension and unit as that of Work.
[9] Magnetism in materials is due to -
A.
electrons at rest
B.
circular motion of electrons
C.
protons at rest
D.
all neutrons at rest
Ans:
circular motion of electrons
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor. The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field.
[2] Which type of reaction produces the most harmful radiation?
A.
Fusion reaction
B.
Fission reaction
C.
Chemical reaction
D.
Photo-Chemical reaction
Ans:
Fission reaction
Explanation :
Radiation is one of the byproducts of radioactive decay of unstable atomic nuclei. Nuclear fission is the process on which the operation of most nuclear power plants is based. When certain nuclei (for example that of uranium-235) are bombarded with neutrons, the nucleus splits into two smaller nuclei of roughly (though not exactly) equal sizes.
[3] Optic fibres are used in :
A.
CAT scans
B.
X-ray photos
C.
Ultrasound scans
D.
Endoscopy
Ans:
Endoscopy
Explanation :
Optical fibres are used in endoscopic instruments that enable doctors to view internal body parts without having to perform surgery. Fernando Alves Martins of Portugal invented the first fiber optic endoscope in 1963-64. Further innovations included using additional fibres to channel light to the objective end from a powerful external source, thereby achieving the high level of full spectrum illumination that was needed for detailed viewing, and colour photography.
[4] Two waves, each of amplitude 1.5 mm and frequency 10 Hz, are travelling in opposite direction with a speed of 20 mm/s. The distance in mm between adjacent nodes is :
A.
1
B.
1.2
C.
1.5
D.
2
Ans:
1
Explanation :
Since the amplitudes, frequency and the speed of both the waves are in same, hence the wavelength of the composite wave will be the same as the single wave.
[5] While catching a ball, a player pulls down his hands to lower the –
A.
force
B.
momentum
C.
impulse
D.
catching time
Ans:
momentum
Explanation :
A cricketer lowers his hands while taking a catch to decrease the rate of momentum. Cricketers increase the time by pulling their hand's backward with the ball while taking a catch. Linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.
[6] A camera uses a to form an image on a piece of film at the back.
A.
convex lens
B.
concave lens
C.
diverging lens
D.
none of these
Ans:
convex lens
Explanation :
A camera consists of three main parts. • The body which is light tight and contains all the mechanical parts. • The lens which is a convex lens. • The film or a charged couple device in the case of a digital camera.
[7] In 1866, John Newlands, an English scientist, arranged the then known elements in the order of increasing atomic masses. He found that every eighth element had properties similar to that of the first. He called it the -
A.
Law of Pentamates
B.
Law of musical notes
C.
Law of Octaves
D.
None of the above
Ans:
Law of Octaves
Explanation :
Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
[8] Which of the following pairs of physical quantities have the same dimensions?
A.
Force and Power
B.
Work and Power
C.
Work and Energy
D.
Momentum and Power
Ans:
Work and Energy
Explanation :
The term energy is used to describe the capacity of a system to do work on another system. Energy of all types (Surface Tension, Kinetic, Potential etc.) have the same dimension and unit as that of Work.
[9] Magnetism in materials is due to -
A.
electrons at rest
B.
circular motion of electrons
C.
protons at rest
D.
all neutrons at rest
Ans:
circular motion of electrons
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Optical fibres are used in endoscopic instruments that enable doctors to view internal body parts without having to perform surgery. Fernando Alves Martins of Portugal invented the first fiber optic endoscope in 1963-64. Further innovations included using additional fibres to channel light to the objective end from a powerful external source, thereby achieving the high level of full spectrum illumination that was needed for detailed viewing, and colour photography.
[4] Two waves, each of amplitude 1.5 mm and frequency 10 Hz, are travelling in opposite direction with a speed of 20 mm/s. The distance in mm between adjacent nodes is :
A.
1
B.
1.2
C.
1.5
D.
2
Ans:
1
Explanation :
Since the amplitudes, frequency and the speed of both the waves are in same, hence the wavelength of the composite wave will be the same as the single wave.
[5] While catching a ball, a player pulls down his hands to lower the –
A.
force
B.
momentum
C.
impulse
D.
catching time
Ans:
momentum
Explanation :
A cricketer lowers his hands while taking a catch to decrease the rate of momentum. Cricketers increase the time by pulling their hand's backward with the ball while taking a catch. Linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.
[6] A camera uses a to form an image on a piece of film at the back.
A.
convex lens
B.
concave lens
C.
diverging lens
D.
none of these
Ans:
convex lens
Explanation :
A camera consists of three main parts. • The body which is light tight and contains all the mechanical parts. • The lens which is a convex lens. • The film or a charged couple device in the case of a digital camera.
[7] In 1866, John Newlands, an English scientist, arranged the then known elements in the order of increasing atomic masses. He found that every eighth element had properties similar to that of the first. He called it the -
A.
Law of Pentamates
B.
Law of musical notes
C.
Law of Octaves
D.
None of the above
Ans:
Law of Octaves
Explanation :
Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
[8] Which of the following pairs of physical quantities have the same dimensions?
A.
Force and Power
B.
Work and Power
C.
Work and Energy
D.
Momentum and Power
Ans:
Work and Energy
Explanation :
The term energy is used to describe the capacity of a system to do work on another system. Energy of all types (Surface Tension, Kinetic, Potential etc.) have the same dimension and unit as that of Work.
[9] Magnetism in materials is due to -
A.
electrons at rest
B.
circular motion of electrons
C.
protons at rest
D.
all neutrons at rest
Ans:
circular motion of electrons
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
A cricketer lowers his hands while taking a catch to decrease the rate of momentum. Cricketers increase the time by pulling their hand's backward with the ball while taking a catch. Linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.
[6] A camera uses a to form an image on a piece of film at the back.
A.
convex lens
B.
concave lens
C.
diverging lens
D.
none of these
Ans:
convex lens
Explanation :
A camera consists of three main parts. • The body which is light tight and contains all the mechanical parts. • The lens which is a convex lens. • The film or a charged couple device in the case of a digital camera.
[7] In 1866, John Newlands, an English scientist, arranged the then known elements in the order of increasing atomic masses. He found that every eighth element had properties similar to that of the first. He called it the -
A.
Law of Pentamates
B.
Law of musical notes
C.
Law of Octaves
D.
None of the above
Ans:
Law of Octaves
Explanation :
Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
[8] Which of the following pairs of physical quantities have the same dimensions?
A.
Force and Power
B.
Work and Power
C.
Work and Energy
D.
Momentum and Power
Ans:
Work and Energy
Explanation :
The term energy is used to describe the capacity of a system to do work on another system. Energy of all types (Surface Tension, Kinetic, Potential etc.) have the same dimension and unit as that of Work.
[9] Magnetism in materials is due to -
A.
electrons at rest
B.
circular motion of electrons
C.
protons at rest
D.
all neutrons at rest
Ans:
circular motion of electrons
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Newlands compared his discovery to the octaves found in music and thus, he called it the ‘Law of Octaves’. It is also known as ‘Newlands’ Law of Octaves’.
[8] Which of the following pairs of physical quantities have the same dimensions?
A.
Force and Power
B.
Work and Power
C.
Work and Energy
D.
Momentum and Power
Ans:
Work and Energy
Explanation :
The term energy is used to describe the capacity of a system to do work on another system. Energy of all types (Surface Tension, Kinetic, Potential etc.) have the same dimension and unit as that of Work.
[9] Magnetism in materials is due to -
A.
electrons at rest
B.
circular motion of electrons
C.
protons at rest
D.
all neutrons at rest
Ans:
circular motion of electrons
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Myopia is commonly known shortsighted. It is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it. This causes the image that one sees when looking at a distant object to be out of focus but in focus when looking at a close object. Eye care professionals most commonly correct myopia through the use of corrective lenses, such as glasses or contact lenses.
[10] The outermost layer of the Sun is called -
A.
chromosphere
B.
photosphere
C.
corona
D.
lithosphere
Ans:
corona
Explanation :
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features
[11] During washing of clothes, we use indigo due to its –
A.
Better cleaning action
B.
Proper pigmental composition
C.
High glorious nature
D.
Very low cost
Ans:
Proper pigmental composition
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process "reduces" the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or "vat". When brought out to the air, it is a blight green. Slowly the ail-changes it to the beautiful deep and rich blue of Indigo.
[12] Light year is a unit of -
A.
Time
B.
distance
C.
Light
D.
intensity of light
Ans:
distance
Explanation :
A light-year is a unit of distance. It is the distance that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second.
[13] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in -
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[14] Water drops are spherical because of -
A.
viscosity
B.
density
C.
polarity
D.
surface tension
Ans:
surface tension
Explanation :
Surface tension is responsible for the shape of liquid droplets. Although easily deformed, droplets of water tend to be pulled into a spherical shape by the cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical.
[15] If the temperature of a piece increases suddenly, the relative humidity–
A.
increases
B.
decreases
C.
remains constant
D.
fluctuates
Ans:
decreases
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.
[16] What changes will happen to a bowl of ice and water kept at exactly zero degree Celsius?
A.
All ice will melt
B.
All water will become ice
C.
No change will happen
D.
Only some ice will melt
Ans:
No change will happen
Explanation :
Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.
[17] Curie point is the temperature at which –
A.
Matter becomes radioactive
B.
A metal loses magnetic properties
C.
A metal loses conductivity
D.
Transmutation of metal occurs
Ans:
A metal loses magnetic properties
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.
[18] Which of the following is true regarding Newland’s Law of Octaves?
A.
It worked well with only lighter elements.
B.
It was applicable only up to calcium.
C.
Both are correct
D.
Both are incorrect.
Ans:
Both are correct
Explanation :
Both the statements are correct. Hence, option C is correct.
[19] When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of -
A.
surface tension
B.
capillarit
C.
viscosity
D.
diffusion
Ans:
surface tension
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Diffusion is the spreading – mixing of gases through molecular motion.
[20] The material used in the fabrication of a transistor is –
A.
Aluminium
B.
Copper
C.
Silicon
D.
Silver
Ans:
Silicon
Explanation :
A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. The first transistors were made from germanium (Ge). Silicon (Si) types currently predominate but certain advanced microwave and high performance versions now employ the compound semiconductor material gallium arsenide (GaAs) and the semiconductor alloy silicon germanium (SiGe).
[21] If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated?
A.
Increases
B.
Decreases
C.
Unchanged
D.
Depends upon the metal
Ans:
Increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using the differential equations of coefficients of expansions, we find that the hole radius increases at the same linear rate as the metal.
[22] The velocity of sound is more in –
A.
water
B.
air
C.
steel
D.
wood
Ans:
steel
Explanation :
Sound travels at different speeds depending on what it is traveling through. Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. They travel over 17 times faster through steel than through air.
[23] Radioactivity is due to –
A.
unstable nucleus
B.
stable nucleus
C.
stable electronic configuration
D.
stable electronic configuration
Ans:
unstable nucleus
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Radioactivity is caused by unstable nuclei trying to become stable by emitting particles and or energy. The nuclei of radioactive substances are unstable due to an unstable ratio of protons to neutrons.
[24] Which conservation principle is applicable in the case of the motion of a rocket?
A.
Conservation of mass
B.
Conservation of charge
C.
Conservation of momentum
D.
Conservation of energy
Ans:
Conservation of momentum
Explanation :
The motion of a rocket is an application of Newton's third law of motion and law of conservation of linear momentum. The operation of a rocket illustrates the conservation of momentum. Just before launching, the momentum of the rocket is zero. When the rocket is fired, it forces a jet of hot gases with a high velocity through the nozzle.
[25] These waves cannot be transmitted through vacuum –
A.
Light
B.
Sound
C.
Heat
D.
Electromagnetic
Ans:
Sound
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.
Explanation :
Sound is a mechanical wave that is created by vibrating objects and propagated through a medium from one location to another. Because mechanical waves rely on particle interaction in order to transport their energy, they cannot travel through regions of space that are void of particles. That is, mechanical waves cannot travel through a vacuum.