McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 151. |
Who defined the law of gravitation? |
| A. | Newton |
| B. | Archimedes |
| C. | Galileo |
| D. | Faraday |
| Answer» A. Newton | |
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Explanation: Sir Isaac Newton brought out his monograph, titled `Philosoplliae Naturalis Principia Mathematica,' in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler's laws of planetaly motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. |
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| 152. |
Which of the following parts of the sunlight makes the solar cooker hot? |
| A. | Ultra violet |
| B. | Red light |
| C. | Infra red |
| D. | Cosmic rays |
| Answer» C. Infra red | |
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Explanation: Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices. |
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| 153. |
What is colour of light related to? |
| A. | Amplitude |
| B. | Frequency |
| C. | Quality |
| D. | Velocity |
| Answer» A. Amplitude | |
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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. |
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| 154. |
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 |
| Answer» C. Pascal's law | |
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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. |
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| 155. |
Which of the following are used for accurately measuring very small time intervals? |
| A. | Pulsars |
| B. | Quartz clocks |
| C. | Atomic clocks |
| D. | White dwarfs |
| Answer» C. Atomic clocks | |
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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 timedistribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS. |
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| 156. |
The material which can be deformed permanently by heat and pressure is called a: |
| A. | Thermoplastic |
| B. | Thermoset |
| C. | Chemical compound |
| D. | Polymer |
| Answer» B. Thermoset | |
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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. |
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| 157. |
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 |
| Answer» A. Neutron Star | |
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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. |
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| 158. |
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 |
| Answer» B. half | |
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Explanation: Radius of a capillary tube is inversely proportional to the height of the liquid |
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| 159. |
The substance which conducts current in the solid state is – |
| A. | diamond |
| B. | graphite |
| C. | iodine |
| D. | sodium chloride |
| Answer» B. graphite | |
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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. |
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| 160. |
Newton is used to measure . |
| A. | Speed |
| B. | Volume |
| C. | Force |
| D. | Area |
| Answer» C. Force | |
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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. |
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| 161. |
The mass density of Kerosene is: |
| A. | more than water |
| B. | equal to water |
| C. | Less than water |
| D. | None of the above |
| Answer» C. Less than water | |
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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. |
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| 162. |
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 |
| Answer» C. It has a high dipole moment | |
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Explanation: 0 |
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| 163. |
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 |
| Answer» C. Non-uniform motion | |
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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. |
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| 164. |
A device used for converting A.C. into D.C. is called – |
| A. | Transformer |
| B. | Rectifier |
| C. | Induction coil |
| D. | Dynamo |
| Answer» B. Rectifier | |
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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, solidstate diodes, silicon-controlledrectifiers and other silicon-based semiconductor switches. |
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| 165. |
Energy of Ultraviolet rays is great than |
| A. | Infra-red rays |
| B. | Gamma rays |
| C. | X-rays |
| D. | Cosmic rays |
| Answer» A. Infra-red rays | |
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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 spectmm, 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. |
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| 166. |
The surface temperature of the Sun is nearly - |
| A. | 2000K |
| B. | 4000K |
| C. | 6000K |
| D. | 8000K |
| Answer» C. 6000K | |
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Explanation: 0 |
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| 167. |
Light year is a unit of - |
| A. | time |
| B. | distance |
| C. | light |
| D. | intensity of light |
| Answer» B. distance | |
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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. |
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| 168. |
The strongest force in nature is – |
| A. | Electrical force |
| B. | Gravitational force |
| C. | Nuclear force |
| D. | Magnetic force |
| Answer» C. Nuclear force | |
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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. |
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| 169. |
According to the theory of relativity, which of the following al-ways remains constant? |
| A. | Length of an object |
| B. | Time |
| C. | Space |
| D. | Velocity of light |
| Answer» D. Velocity of light | |
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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. |
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| 170. |
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 |
| Answer» B. Liquid dispersed in gas | |
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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. |
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| 171. |
'SONAR' is mostly used by - |
| A. | Doctors |
| B. | Engineers |
| C. | Astronauts |
| D. | Navigators |
| Answer» D. Navigators | |
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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. |
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| 172. |
Electrostatic precipitator is used to control — |
| A. | Air pollution |
| B. | Water pollution |
| C. | Solid waste |
| D. | Noise pollution |
| Answer» A. Air pollution | |
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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. |
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| 173. |
The time period of a second’s pendulum is – |
| A. | 1 second |
| B. | 2 seconds |
| C. | 0.5 second |
| D. | 1.5 seconds |
| Answer» B. 2 seconds | |
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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 frequencyof 1/2 Hz. At standard gravity its length is 0.994 m. |
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| 174. |
Persistance of vision is the principle behind – |
| A. | Camera |
| B. | Spectroscope |
| C. | Cinema |
| D. | Periscope |
| Answer» C. Cinema | |
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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. Persistence of vision is still the accepted term for this phenomenon in the realm of cinema history and theory. |
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| 175. |
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 |
| Answer» A. they contain free electrons | |
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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. |
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| 176. |
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 |
| Answer» A. Molecular motion in a gas would cease | |
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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. |
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| 177. |
An aircraft can perform aerobatic manoeuvres in a vertical loop because of- |
| A. | gravity |
| B. | centripetal force |
| C. | weight |
| D. | centrifugal force |
| Answer» A. gravity | |
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Explanation: It happens because of gravity. A key feature of super maneuvering aircrafts is a high thrust-to-weight ratio; that is, the comparison of the force produced by the engines to the aircraft's weight, which is the force of gravity on the aircraft. |
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| 178. |
A photostat machine works on – |
| A. | electromagnetic image making |
| B. | electrostatic image making |
| C. | magnetic image making |
| D. | thermal image making |
| Answer» B. electrostatic image making | |
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Explanation: A photocopier uses electrostatic charge to produce a copy. The original document is placed onto a sheet of glass. An image of this page is projected onto a positively charged drum. The drum has a coating which conducts electricity when light falls on it. The parts of the drum which are lit by the projected image losetheir electrostatic charge when they start to conduct. |
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| 179. |
If a copper wire is increased to double its length, its resistance will become – |
| A. | four times |
| B. | one-fourth |
| C. | double |
| D. | half |
| Answer» C. double | |
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Explanation: There is a direct relationship between the amount of resistance encountered by charge and the length of wire it must traverse. After all, if resistance occurs as the result of collisions between charge carriers and the atoms of the wire, then there is likely to be more collisions in a longer wire. |
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| 180. |
In a diesel engine the high temperature needed to ignite the fuel is achieved by – |
| A. | using heat from exhaust |
| B. | the battery |
| C. | compressing air in the cylinders |
| D. | an electrical spark |
| Answer» C. compressing air in the cylinders | |
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Explanation: Diesel engines use the heat of compressed air to ignite the fuel (intakes air, compresses it, then injects fuel). Diesel engines need high compression ratios to generate the high temperatures required for fuel auto ignition. |
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| 181. |
Which of the following physical quantities changes or tends to change the state of rest or of uniform motion of a body in a straight line? |
| A. | Momentum |
| B. | Mass |
| C. | Force |
| D. | Inertia |
| Answer» C. Force | |
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Explanation: Force is an agent which changes or tends to change the state of rest or of uniform motion of a body. |
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| 182. |
Which of the following in the correct device that converts thermal energy into electrical energy? |
| A. | constant volume gas thermometer |
| B. | liquid-in-glass thermometer |
| C. | thermopile |
| D. | none of these |
| Answer» C. thermopile | |
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Explanation: A thermopile is an electronic device that converts thermal energy into electrical energy. |
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| 183. |
To measure the speed of an approaching car a police officer shines – |
| A. | light waves on it |
| B. | microwaves on it |
| C. | radio waves on it |
| D. | ultra high frequency waves on it |
| Answer» C. radio waves on it | |
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Explanation: Radar, which stands for radio detection and ranging, is a system that uses reflected radio waves to detect objects and measure their distance and speed. For example, police use radar to calculate the speed of cars. |
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| 184. |
A person wears spectators with concave lenses. It means that normally (when not using glasses), the image of distant objects is focused in his eyes – |
| A. | behind the retina |
| B. | in front of the retina |
| C. | on the retina |
| D. | on the blind spot |
| Answer» B. in front of the retina | |
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Explanation: A concave lens is used to correct short-sightedness (myopia). In myopia, images are formed in front of the retina, resulting in a blurred image. This occurs when the eye is relatively too long or the refractive powers of the cornea and lens of the eye are relatively too strong. |
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| 185. |
Ohm's law defines – |
| A. | a resistance |
| B. | current only |
| C. | voltage only |
| D. | both current and voltage |
| Answer» A. a resistance | |
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Explanation: Ohm's law a law relating the voltage difference between two points, the electric current flowing between them, and the resistance of the path of the current. |
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| 186. |
Lakes freeze in cold countries in winter, leaving the water underneath at – |
| A. | 0°C |
| B. | 0°F |
| C. | 4°C |
| D. | 4°F |
| Answer» C. 4°C | |
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Explanation: Lake ice cover is seasonal and occurs where average daily temperature is below the freezing point. Once formed the lake ice thickens over the course of the winter as the temperature gets colder. The lakes thermal structure prepares for ice with 0 (zero) degrees Celsius water at the surface and denser 4 degrees Celsius at the bottom. |
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| 187. |
Which one of the following determines the sharpness of image in a camera? |
| A. | The aperture |
| B. | The exposure time |
| C. | The focal length of the lens |
| D. | Size of the camera |
| Answer» A. The aperture | |
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Explanation: Image quality is a characteristic of an image that measures the perceived image degradation (typically, compared to an ideal or perfect image). Imaging systems may introduce some amounts of distortion or artifacts in the signal, so the quality assessment is an important problem. Sharpness determines the amount of detail an image can convey. |
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| 188. |
Light from the Sun reaches us in nearly |
| A. | 2 minutes |
| B. | 4 minutes |
| C. | 8 minutes |
| D. | 16 minutes |
| Answer» C. 8 minutes | |
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Explanation: The sun’s light takes about 8 minutes to reach the Earth after it has been emitted from the sun’s surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto. |
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| 189. |
Red data book contains data of which of the following? |
| A. | All plant species |
| B. | All animal species |
| C. | All endangered species |
| D. | All extinct species |
| Answer» C. All endangered species | |
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Explanation: The Red Data Book is the state document established for documenting rare and endangered species of animals, plants and fungi as well as some local sub-species that exist within the territory of the state or country. |
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| 190. |
Second’s pendulum is a pendulum which executes one oscillation in: |
| A. | Half a second |
| B. | One second |
| C. | Two seconds |
| D. | None of these |
| Answer» C. Two seconds | |
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Explanation: A pendulum is a weight suspended from a pivot so that it can swing freely. 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. |
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| 191. |
Which of the following is most elastic? |
| A. | Rubber |
| B. | Wet clay |
| C. | Steel |
| D. | Plastic |
| Answer» C. Steel | |
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Explanation: In physics, elasticity is a physical property of materials which return to their original shape after the stress that caused their deformation is no longer applied. For very small deformations, most elastic materials, such as springs, exhibit linear elasticity. This means that they are characterized by a linear relationship between stress and strain (the relative amount of deformation). |
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| 192. |
Sound cannot pass through – |
| A. | Water |
| B. | Steel |
| C. | Air |
| D. | Vacuum |
| Answer» D. Vacuum | |
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Explanation: Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing. Sound also travels through plasma. Sound is a sequence of waves of pressure that propagates through compressible media such as air or water. (Sound can propagate through solids as well, but there are additional modes of propagation). Sound cannot travel through a vacuum because it does not provide the medium to propagate. |
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| 193. |
The instrument used to measure the speed of the wind is – |
| A. | Altimeter |
| B. | Anemometer |
| C. | Chronometer |
| D. | Dosimeter |
| Answer» B. Anemometer | |
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Explanation: An anemometer is a device for measuring wind speed, and is a common weatherstation instrument. The term is derived from the Greek word anemos, meaning wind, and is used to describe any airspeed measurement instrument used in meteorology or aerodynamics. The first known description of an anemometer was given by Leon Battista Alberti around 1450. |
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| 194. |
An optically plane surface reflects a beam of light – |
| A. | as a parallel beam in one direction |
| B. | as diffused beams in all d rections |
| C. | as parallel beams in all direactions |
| D. | as a diffused beam in one direction |
| Answer» A. as a parallel beam in one direction | |
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Explanation: An optically plane surface reflects a beam of light as a parallel beam in one direction. The set of incident rays are reflected as a set of rays. In other words, a beam of light is reflected as a beam of light if the mirror is plane and its reflecting surface is smooth. This type of reflection of a set of rays is called Specular Reflection. |
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| 195. |
The slope of a velocity-time graph represents – |
| A. | acceleration |
| B. | displacement |
| C. | distance |
| D. | speed |
| Answer» A. acceleration | |
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Explanation: A plot of velocity-time is used to determine the acceleration of an object (the slope). If the acteleration is zero, then the velocity-time graph is a horizontal line (i.e., the slope is zero). If the acceleration is positive, then the line is an upward sloping line (i.e., the slope is positive). |
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| 196. |
The material which can be deformed permanently by heat and pressure is called a |
| A. | thermoset |
| B. | thermoplastic |
| C. | chemical compound |
| D. | polymer |
| Answer» A. thermoset | |
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Explanation: A thermosetting polymer, resin, or plastic, often called a thermoset, is a polymer that is irreversibly hardened by curing from a soft solid or viscous liquid prepolymer or resin. |
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| 197. |
On planet Earth, there is no centrifugal force at the – |
| A. | Equator |
| B. | Tropic of Cancer |
| C. | Tropic of Capricorn |
| D. | Poles |
| Answer» D. Poles | |
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Explanation: Some common examples of centrifugal force at work are mud flying off a tire and children feeling a force pushing them outwards while spinning on a roundabout. |
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| 198. |
Gas thermometers are more sensitive than the liquid thermometers because of the gases - |
| A. | have low specific heat |
| B. | have high specific heat |
| C. | have large coefficient of expansion |
| D. | are lighter |
| Answer» A. have low specific heat | |
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Explanation: Gas thermometers are more sensitive because gas has low specific heat than liquids. |
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| 199. |
The earth-wire of a cable is connected to – |
| A. | the outer metallic body of the appliance |
| B. | the fuse of the appliance |
| C. | the filament of the appliance |
| D. | short circuitry of the appliance |
| Answer» B. the fuse of the appliance | |
| Explanation: Earth wire prevents Electric shocks. It is connected to the electrical cable of an appliance to prevent electric shocks. Actually it has very low resistance and allows current to pass through it easily. | |
| 200. |
The best conductor of heat among the following is – |
| A. | alcohol |
| B. | mercury |
| C. | ether |
| D. | water |
| Answer» B. mercury | |
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Explanation: Since mercury is 13+ times as dense as water, a given volume of mercury would carry about 4.4 times as much heat, so mercury is best conductor of heat among the given options. It is the only metal that is liquid at standard conditions for temperature and pressure. Mercury has one of the narrowest ranges of its liquid state of any metal. |
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