[1] What is colour of light related to?
A.
Amplitude
B.
Frequency
C.
Quality
D.
Velocity
Ans:
Amplitude
Explanation :
Colour or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue, and others. Colour derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Colour categories and physical specifications of colour are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra. By defining a colour space, colours can be identified numerically by their coordinates.
[2] What principle/law explains the working of the hydraulic brakes in automobiles?
A.
Bernoulli's law
B.
Posieulli's principle
C.
Pascal's law
D.
Archimedes' principle
Ans:
Pascal's law
Explanation :
Hydraulic brakes work on the principle of Pascal's law which states that "pressure at a point in a fluid is equal in all directions in space". According to this law when pressure is applied on a fluid it travels equally in all directions so that uniform braking action is applied on all four wheels. The hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit, which is usually near the operator of the vehicle, to the actual brake mechanism, which is usually at or near the wheel of the vehicle.
[3] Which of the following are used for accurately measuring very small time intervals?
A.
Pulsars
B.
Quartz clocks
C.
Atomic clocks
D.
White dwarfs
Ans:
Atomic clocks
Explanation :
An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.
[4] The material which can be deformed permanently by heat and pressure is called a:
A.
Thermoplastic
B.
Thermoset
C.
Chemical compound
D.
Polymer
Ans:
Thermoset
Explanation :
Thermoset materials are those materials that are made by polymers joined together by chemical bonds, acquiring a highly cross linked polymer structure. They cannot melt.
[5] The mass of a star is two times the mass of the Sun. How it will come to an end?
A.
Neutron Star
B.
Black hole
C.
White Dwarf
D.
Red Giant
Ans:
Neutron Star
Explanation :
The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type lc supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons.
[6] If the diameter of a capillary is doubled, then the rise of water in it will be –
A.
two times
B.
half
C.
four times
D.
no change
Ans:
half
Explanation :
Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if radius of the tube is doubled, rise of level of water will becomes half of the previous rise in capillary tube. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.
[7] The substance which conducts current in the solid state is –
A.
diamond
B.
graphite
C.
iodine
D.
sodium chloride
Ans:
graphite
Explanation :
The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is delocalized and can move between the different layers, therefore carrying an electrical charge through the network of carbon atoms, a conductor is a material which contains movable electric charges. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.
[8] Newton is used to measure .
A.
Speed
B.
Volume
C.
Force
D.
Area
Ans:
Force
Explanation :
The newton (N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
[9] The mass density of Kerosene is:
A.
more than water
B.
equal to water
C.
Less than water
D.
None of the above
Ans:
Less than water
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
Colour or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue, and others. Colour derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Colour categories and physical specifications of colour are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra. By defining a colour space, colours can be identified numerically by their coordinates.
[2] What principle/law explains the working of the hydraulic brakes in automobiles?
A.
Bernoulli's law
B.
Posieulli's principle
C.
Pascal's law
D.
Archimedes' principle
Ans:
Pascal's law
Explanation :
Hydraulic brakes work on the principle of Pascal's law which states that "pressure at a point in a fluid is equal in all directions in space". According to this law when pressure is applied on a fluid it travels equally in all directions so that uniform braking action is applied on all four wheels. The hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit, which is usually near the operator of the vehicle, to the actual brake mechanism, which is usually at or near the wheel of the vehicle.
[3] Which of the following are used for accurately measuring very small time intervals?
A.
Pulsars
B.
Quartz clocks
C.
Atomic clocks
D.
White dwarfs
Ans:
Atomic clocks
Explanation :
An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.
[4] The material which can be deformed permanently by heat and pressure is called a:
A.
Thermoplastic
B.
Thermoset
C.
Chemical compound
D.
Polymer
Ans:
Thermoset
Explanation :
Thermoset materials are those materials that are made by polymers joined together by chemical bonds, acquiring a highly cross linked polymer structure. They cannot melt.
[5] The mass of a star is two times the mass of the Sun. How it will come to an end?
A.
Neutron Star
B.
Black hole
C.
White Dwarf
D.
Red Giant
Ans:
Neutron Star
Explanation :
The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type lc supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons.
[6] If the diameter of a capillary is doubled, then the rise of water in it will be –
A.
two times
B.
half
C.
four times
D.
no change
Ans:
half
Explanation :
Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if radius of the tube is doubled, rise of level of water will becomes half of the previous rise in capillary tube. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.
[7] The substance which conducts current in the solid state is –
A.
diamond
B.
graphite
C.
iodine
D.
sodium chloride
Ans:
graphite
Explanation :
The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is delocalized and can move between the different layers, therefore carrying an electrical charge through the network of carbon atoms, a conductor is a material which contains movable electric charges. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.
[8] Newton is used to measure .
A.
Speed
B.
Volume
C.
Force
D.
Area
Ans:
Force
Explanation :
The newton (N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
[9] The mass density of Kerosene is:
A.
more than water
B.
equal to water
C.
Less than water
D.
None of the above
Ans:
Less than water
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.
[4] The material which can be deformed permanently by heat and pressure is called a:
A.
Thermoplastic
B.
Thermoset
C.
Chemical compound
D.
Polymer
Ans:
Thermoset
Explanation :
Thermoset materials are those materials that are made by polymers joined together by chemical bonds, acquiring a highly cross linked polymer structure. They cannot melt.
[5] The mass of a star is two times the mass of the Sun. How it will come to an end?
A.
Neutron Star
B.
Black hole
C.
White Dwarf
D.
Red Giant
Ans:
Neutron Star
Explanation :
The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type lc supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons.
[6] If the diameter of a capillary is doubled, then the rise of water in it will be –
A.
two times
B.
half
C.
four times
D.
no change
Ans:
half
Explanation :
Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if radius of the tube is doubled, rise of level of water will becomes half of the previous rise in capillary tube. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.
[7] The substance which conducts current in the solid state is –
A.
diamond
B.
graphite
C.
iodine
D.
sodium chloride
Ans:
graphite
Explanation :
The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is delocalized and can move between the different layers, therefore carrying an electrical charge through the network of carbon atoms, a conductor is a material which contains movable electric charges. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.
[8] Newton is used to measure .
A.
Speed
B.
Volume
C.
Force
D.
Area
Ans:
Force
Explanation :
The newton (N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
[9] The mass density of Kerosene is:
A.
more than water
B.
equal to water
C.
Less than water
D.
None of the above
Ans:
Less than water
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type lc supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons.
[6] If the diameter of a capillary is doubled, then the rise of water in it will be –
A.
two times
B.
half
C.
four times
D.
no change
Ans:
half
Explanation :
Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if radius of the tube is doubled, rise of level of water will becomes half of the previous rise in capillary tube. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.
[7] The substance which conducts current in the solid state is –
A.
diamond
B.
graphite
C.
iodine
D.
sodium chloride
Ans:
graphite
Explanation :
The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is delocalized and can move between the different layers, therefore carrying an electrical charge through the network of carbon atoms, a conductor is a material which contains movable electric charges. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.
[8] Newton is used to measure .
A.
Speed
B.
Volume
C.
Force
D.
Area
Ans:
Force
Explanation :
The newton (N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
[9] The mass density of Kerosene is:
A.
more than water
B.
equal to water
C.
Less than water
D.
None of the above
Ans:
Less than water
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
The structure of graphite is unlike most other network substances. It is formed in ‘sheets’ of carbon atoms, each of which is bonded to only three others. The fourth valence electron of the carbon atom is delocalized and can move between the different layers, therefore carrying an electrical charge through the network of carbon atoms, a conductor is a material which contains movable electric charges. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds.
[8] Newton is used to measure .
A.
Speed
B.
Volume
C.
Force
D.
Area
Ans:
Force
Explanation :
The newton (N) is the International System of Units (SI) derived unit of force. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion.
[9] The mass density of Kerosene is:
A.
more than water
B.
equal to water
C.
Less than water
D.
None of the above
Ans:
Less than water
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
Kerosene is lighter than water in terms of density. Density of kerosene is 820 kg /m3, means if you take 1000 liters of kerosene it would weight 820 kg. Whereas density of water is 1000 kg /m3 means if you take 1000 liters of water it would weight 1000 kg.
[10] Water is a good solvent of ionic salts because -
A.
It has no colour
B.
It has a boiling point
C.
It has a high dipole moment
D.
It has a high specific heat
Ans:
It has a high dipole moment
Explanation :
Water is a good solvent of ionic salts because it has a high dipole moment. Salts are ionic compounds which, when dissolved in water, break up completely into ions. They arise by the reaction of acids with bases, and they always contain either a metal cation or a cation derived from ammonium (NH4+).
[11] For which type of motion, the distance time graph is not a straight line and can be any kind of curve?
A.
Uniform motion
B.
Circular motion
C.
Non-uniform motion
D.
Linear motion
Ans:
Non-uniform motion
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
When the motion is uniform, the distance time graph is a straight line with a slope. When the motion is non-uniform, the distance time graph is not a straight line. It can be any kind of curve.
[12] A device used for converting a.c. into d.c. is called –
A.
Transformer
B.
Rectifier
C.
Induction coil
D.
Dynamo
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches.
[13] Energy of Ultraviolet rays is great than –
A.
Infra-red rays
B.
Gamma rays
C.
X-rays
D.
Cosmic rays
Ans:
Infra-red rays
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy.
[14] The surface temperature of the Sun is nearly -
A.
2000K
B.
4000K
C.
6000K
D.
8000K
Ans:
6000K
Explanation :
0
[15] 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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
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.
[16] The strongest force in nature is –
A.
Electrical force
B.
Gravitational force
C.
Nuclear force
D.
Magnetic force
Ans:
Nuclear force
Explanation :
The nuclear force (or nucleon-nucleon interaction or residual strong force) is the force between two or more nucleons. It is responsible for binding of protons and neutrons into atomic nuclei.
[17] According to the theory of relativity, which of the following always remains constant?
A.
Length of an object
B.
Time
C.
Space
D.
Velocity of light
Ans:
Velocity of light
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
The theory of relativity, or simply relativity, generally encompasses two theories of Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space and time can dilate. Space time: space and time should be considered together and in relation to each other. The speed of light is nonetheless invariant, the same for all observers.
[18] Fog is an example of –
A.
Gas dispersed in has
B.
Liquid dispersed in gas
C.
Solid dispersed in gas
D.
Solid dispersed in liquid
Ans:
Liquid dispersed in gas
Explanation :
Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes). Fog is distinguished from mist only by its density, as expressed in the resulting decrease in visibility.
[19] 'SONAR' is mostly used by -
A.
Doctors
B.
Engineers
C.
Astronauts
D.
Navigators
Ans:
Navigators
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water.
[20] Electrostatic precipitator is used to control —
A.
Air pollution
B.
Water pollution
C.
Solid waste
D.
Noise pollution
Ans:
Air pollution
Explanation :
An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing has (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
[21] The time period of a second’s pendulum is –
A.
1 second
B.
2 seconds
C.
0.5 second
D.
1.5 seconds
Ans:
2 seconds
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
A seconds pendulum is a pendulum whose period is precisely two seconds; one second for a swing in one direction and one second for the return swing, a frequency of 1/2 Hz. At standard gravity its length is 0.994 m.
[22] Persistance of vision is the principle behind –
A.
Camera
B.
Spectroscope
C.
Cinema
D.
Periscope
Ans:
Cinema
Explanation :
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.
[23] Metals are good conductors of electricity because –
A.
they contain free electrons
B.
the atoms are lightly packed
C.
they have high melting point
D.
All of the above
Ans:
they contain free electrons
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.
[24] Formation of shadows can be explained by -
A.
rectilinear propagation of light
B.
reflection
C.
refraction
D.
total internal reflection
Ans:
rectilinear propagation of light
Explanation :
In this position, the head light will be at the principal focus so that the rays of light falling on the concave mirror will be rendered parallel.
[25] The absolute zero is a temperature at which -
A.
Molecular motion in a gas would cease
B.
Water freezes
C.
All gases become liquid
D.
All gases become solid
Ans:
Molecular motion in a gas would cease
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.
Explanation :
Absolute zero is the lowest possible temperature where nothing could be colder and no heat energy remains in a substance. That temperature Molecular motion in a gas would cease.