McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 1. |
A light year is a measure of : |
| A. | Speed |
| B. | Velocity |
| C. | Distance |
| D. | Time |
| Answer» C. Distance | |
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Explanation: A light-year is a unit of length equal to just under 10 trillion kilometres (or about 6 trillion miles). As defined by the International Astronomical Union (TAU), a light-year is the distance that light travels in a vacuum in one Julian year. Note that the lightyear is a measure of distance (rather than, as is sometimes misunderstood, a measure of time). |
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| 2. |
A device which is used to limit the current in an electrical circuit is called a - |
| A. | Grid |
| B. | Fuse |
| C. | Hub |
| D. | Conductor |
| Answer» B. Fuse | |
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Explanation: A fuse places a limit on the amount of current that can be drawn by an electric circuit by opening (blowing or melting) when the current exceeds a preset limit. This protects the circuit and the surroundings from fire or damage in the case of an overload or short circuit. |
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| 3. |
Two rods, one of copper and other of steel, experience the same up thrust when placed in water. Thus, both have – |
| A. | equal volume |
| B. | equal weight |
| C. | equal density |
| D. | equal mass |
| Answer» A. equal volume | |
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Explanation: When a body is placed in water, the upthrust or buoyant force acting on it depends upon the following factors: (1) Volume of the body submerged in the liquid - (V), or volume of the liquid displaced - (V); (ft) Density of the liquid - (d); and (Hi) Acceleration due to gravity In-line. |
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| 4. |
Minimum numbers of unequal vectors which can give zero resultant are - |
| A. | Two |
| B. | Three |
| C. | Four |
| D. | More than four |
| Answer» B. Three | |
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Explanation: Minimum number of unequal vectors which can give three zero resultants. |
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| 5. |
Water is not suitable as a calorimetric substance because it – |
| A. | has high specific heat |
| B. | is a good conductor |
| C. | has high boiling point |
| D. | low latent heat of vaporization |
| Answer» A. has high specific heat | |
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Explanation: The specific heat of water is higher than all other common substances. Hence, water is used for heating purposes (as in hot water bottles) and for cooling purposes (as in radiators of cars). Off all the liquids, mercury has the lowest specific heat due to which it is used as a thermometric liquid. |
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| 6. |
When a body falls from an aeroplane, there is increase in its – |
| A. | Kinetic energy |
| B. | Mass |
| C. | Acceleration |
| D. | Potential energy |
| Answer» C. Acceleration | |
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Explanation: The energy possessed by a body by virtue of its motion is called kinetic energy. Potential Energy is the energy possessed by virtue of its position or configuration. When a body falls from an aeroplane, there is increase in its acceleration. |
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| 7. |
Which among the following types of coal produces most heat per unit? |
| A. | Coal |
| B. | Lignite |
| C. | Anthracite |
| D. | Pit |
| Answer» C. Anthracite | |
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Explanation: The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. Anthracite ("coal-like") is a hard, compact variety of mineral coal that has a high luster. It has the highest carbon content, the fewest impurities, and the highest calorific content of all types of coals, which also include bituminous coal and lignite. |
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| 8. |
Which among the following waves is used for communication by artificial satellites? |
| A. | Micro waves |
| B. | Radio waves |
| C. | A. M. |
| D. | Frequency of 1016 series |
| Answer» A. Micro waves | |
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Explanation: For fixed (point-to-point) services, communications satellites provide a microwave radio relay technology complementary to that of communication cables. They are also used for mobile applications such as communications to ships, vehicles, planes and hand-held terminals, and for TV and radio broadcasting. Microwave technology is extensively used for point-to-point telecommunications (i.e., non broadcast uses). |
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| 9. |
Energy is continuously created in the sun due to – |
| A. | Nuclear fusion |
| B. | Nuclear fission |
| C. | Radioactivity |
| D. | Artificial radioactivity |
| Answer» A. Nuclear fusion | |
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Explanation: The central mass of the sun becomes increasingly hot and dense. eventually initiating thermonuclear fusion in its core. It is thought that almost all other stars form by this process. nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. |
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| 10. |
When the barometer reading dips suddenly, it is an indication of – |
| A. | Hot weather |
| B. | Calm weather |
| C. | Storm |
| D. | Dry weather |
| Answer» C. Storm | |
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Explanation: Sudden and great fluctuations of the barometer at any time of the year indicate unsettled weather for several days, perhaps a fortnight. If the barometer falls two or threetenths of an inch in four hours, one can expect a gale of wind. If the surface of the mercury in the cistern of the barometer vibrates upon the approach of a storm, the gale can be expected to be severe. |
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| 11. |
Good conductor of electricity is – |
| A. | dry air |
| B. | paper |
| C. | kerosene |
| D. | graphite |
| Answer» D. graphite | |
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Explanation: Graphite has a tendency to behave very much like a metal because the carbon molecules arrange themselves into a lattice structure. The crystal lattice is the same orientation that metal forms, and it allows the free-movement of electrons, making it a good electrical conductor. The characteristics possesses by the graphite for conduction is far better than the dry air paper and kerosene and that's what makes it a good conductor. |
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| 12. |
The fourth state of matter is known as |
| A. | Gas |
| B. | Vapour |
| C. | Plasma |
| D. | Electrons |
| Answer» C. Plasma | |
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Explanation: The characteristics of plasmas are significantly different from those of ordinary neutral gases so that plasmas are considered a distinct "fourth state of matter, plasma is a state of matter similar to gas in which a certain portion of the particles is ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions. |
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| 13. |
Radio waves, microwaves, infra-red spectrum, ultraviolet rays, X-rays and gamma rays are classified as ______. |
| A. | light waves |
| B. | electromagnetic waves |
| C. | electric waves |
| D. | magnetic waves |
| Answer» B. electromagnetic waves | |
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Explanation: Electromagnetic radiation is the radiant energy released by certain electromagnetic processes. It consists of electromagnetic waves which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum. |
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| 14. |
Which one of the following instruments is used to study dispersion of light? |
| A. | Microscope |
| B. | Telescope |
| C. | Spectrometer |
| D. | Photometer |
| Answer» C. Spectrometer | |
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Explanation: Dispersion occurs when different frequencies of light have different phase velocities, due either to material properties (material dispersion) or to the geometry of an optical waveguide (waveguide dispersion). A spectrometer (spectro-photometer, spectrograph or spectroscope) is an instrument used to measure properties alight over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. |
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| 15. |
A falling drop of rain water ac-quires the spherical shape due to – |
| A. | Viscosity |
| B. | Surface Tension |
| C. | Atmospheric pressure |
| D. | Gravitational force |
| Answer» B. Surface Tension | |
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Explanation: Raindrops start out as round high in the atmosphere as water collects on dust and smoke particles in clouds. But as raindrops fall, they lose their rounded shape. A raindrop falling through the atmosphere forms as a roughly spherical structure due to the surface tension of water. This surface tension is the "skin" of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules. |
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| 16. |
This scientist gave the law- ‘Properties of elements are a periodic function of their atomic number.’ This property of the fundamental importance of atomic number was discovered by- |
| A. | Johann Wolfgang Döbereiner |
| B. | John Newlands |
| C. | Dmitri lvanovich Mendeléev |
| D. | Henry Moseley |
| Answer» D. Henry Moseley | |
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Explanation: In 1913, Henry Moseley showed that the atomic number of an element is a more fundamental property than its atomic mass as described below. |
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| 17. |
The mass and energy equivalent to 1 a.m.u. respectively are - |
| A. | 1.67 x 10−27 g, 9.30 MeV |
| B. | 1.67 x 10−27kg, 930 MeV |
| C. | 1.67 x 10−27kg, 1 MeV |
| D. | 1.67 x 10−34 kg, 1 MeV |
| Answer» B. 1.67 x 10−27kg, 930 MeV | |
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Explanation: The mass and energy equivalent to 1 a.m.u. respectively are 1.67 x 10−27kg, 930 MeV. |
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| 18. |
A spherical ball made of steel when dropped in mercury container will – |
| A. | sink in mercury |
| B. | will be on the surface of mercury |
| C. | will be partly immersed mercury |
| D. | will dissolve in mercury |
| Answer» B. will be on the surface of mercury | |
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Explanation: The density of steel usually ranges between 7.75 and 8.05 g/cm3 and the density of mercury is 13.534 g/cm3. Mercury is denser than steel this will mean that the buoyant force is large enough to float the steel ball. Different materials usually have different densities, so density is an important concept regarding buoyancy, purity and packaging. |
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| 19. |
The sounds having a frequency of 20 Hertz to 20,000 Hertz are known as – |
| A. | Audible sounds |
| B. | Ultrasonics |
| C. | Infrasonics |
| D. | Megasonics |
| Answer» A. Audible sounds | |
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Explanation: An audio frequency is characterized as a periodic vibration whose frequency is audible to the average human. It is the property of sound that most determines pitch and is measured in hertz (Hz).The generally accepted standard range of audible frequencies is 20 to 20,000 Hz, although the range of frequencies individuals hear is greatly influenced by environmental factors. |
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| 20. |
Gamma rays have greatest similarity with – |
| A. | α-rays |
| B. | β-rays |
| C. | X-rays |
| D. | U.V.-rays |
| Answer» C. X-rays | |
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Explanation: Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as y, is electromagnetic radiation of high frequency and therefore high energy. Gamma rays are ionizing radiation and are thus biologically hazardous. They are classically produced by the decay from high energy states of atomic nuclei (gamma decay), but are also created by other processes. |
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| 21. |
In the absence of ozone layer, Which rays will enter into atmosphere? |
| A. | Infrared |
| B. | Visible |
| C. | Ultraviolet |
| D. | X-rays |
| Answer» C. Ultraviolet | |
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Explanation: The ozone layer is a layer in Earth's atmosphere containing relatively high concentrations of ozone (O3). The ozone layer absorbs 97-99% of the Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. |
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| 22. |
Light year is the unit of - |
| A. | Frequency |
| B. | Distance |
| C. | Energy |
| D. | Power |
| 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. So in one year, it can travel about 10 trillion km. |
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| 23. |
An object at rest will remain at rest and an object in motion will remain in motion until and unless it is acted upon by an external force. This is Newton's – |
| A. | First law |
| B. | Second law |
| C. | Third law |
| D. | Fourth law |
| Answer» A. First law | |
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Explanation: Newton's first law of motion -sometimes referred to as the law of inertia-states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. |
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| 24. |
Cathode rays when obstructed by metal cause emission of - |
| A. | γ – ray |
| B. | X – ray |
| C. | α – ray |
| D. | β – ray |
| Answer» B. X – ray | |
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Explanation: 0 |
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| 25. |
Sensation of sound persists in our brain for about - |
| A. | 0.001s |
| B. | 0.2s |
| C. | 0.1s |
| D. | 10s |
| Answer» C. 0.1s | |
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Explanation: The sensation of hearing of any sound persists in our brain for 0.1s.This is called the persistence of hearing. |
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| 26. |
Tape recorder should not be kept near one of the following things – |
| A. | Clock |
| B. | Magnet |
| C. | Electrical switchboard |
| D. | Radio |
| Answer» B. Magnet | |
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Explanation: The cassette tape contains a magnetic strip wound around two spools. Tiny magnetic particles are randomly scattered throughout the tape. A tape recorder should not be kept near a magnet as the latter can cause the magnetic material to be pushed and pulled out of place. Rearranging the magnetic particles erases the sound. |
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| 27. |
Which physical quantity is measured in ‘siemens’? |
| A. | Electric potential |
| B. | Electrical conductance |
| C. | Magnetic flux |
| D. | Refractive index |
| Answer» B. Electrical conductance | |
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Explanation: The Siemens is the unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI). |
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| 28. |
The surface tension of water on adding detergent to it – |
| A. | increases |
| B. | decreases |
| C. | no change |
| D. | becomes zero |
| Answer» B. decreases | |
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Explanation: In the solid and liquid phase, water molecules are bonded to each other by virtue of an interaction between hydrogen atoms on one molecule and the oxygen atom of another — the process is referred to as "hydrogen bonding." The result is a kind of "skin" on liquid water's surface. |
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| 29. |
In a refrigerator, the cooling system should always be – |
| A. | at the top |
| B. | at the bottom |
| C. | at the middle |
| D. | can be anywhere |
| Answer» B. at the bottom | |
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Explanation: The compressor is the motor (or engine) of the cooling system. It is normally at the bottom of the refrigerator in the back. The compressor runs whenever the refrigerator thermostat calls for cooling. |
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| 30. |
Which of the following is optical illusion? |
| A. | Rainbow |
| B. | Earthshine |
| C. | Halo |
| D. | Mirage |
| Answer» D. Mirage | |
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Explanation: A mirage is a naturally occurring optical illusion or phenomenon in which light rays are bent due to refraction in layers of air of varying density. The image usually is upside down, enhancing the illusion that the sky image seen in the distance is really a water or oil puddle acting as a mirror. |
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| 31. |
The base of an electric iron is brightly polished mainly - |
| A. | to make it smooth and frictionless |
| B. | to make it rust-proof |
| C. | to reduce heat loss by radiation |
| D. | to make it more durable |
| Answer» C. to reduce heat loss by radiation | |
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Explanation: Polished surfaces are poor radiators of heat. So loss of heat on that account is reduced and the electric iron remains hotter than otherwise. |
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| 32. |
If the length of a simple pendulum is halved then its period of oscillation is - |
| A. | doubled |
| B. | halved |
| C. | increased by a factor √ 2 |
| D. | decreased by a factor √ 2 |
| Answer» D. decreased by a factor √ 2 | |
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Explanation: 0 |
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| 33. |
Lux is the SI unit of - |
| A. | intensity of illumination |
| B. | luminous efficiency |
| C. | luminous flux |
| D. | luminous intensity |
| Answer» A. intensity of illumination | |
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Explanation: The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m2. |
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| 34. |
Eclipses occur due to which optical phenomena? |
| A. | Reflection |
| B. | Refraction |
| C. | Rectilinear propagation |
| D. | Diffraction |
| Answer» C. Rectilinear propagation | |
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Explanation: An eclipse is an astronomical event that occurs when an astronomical object is temporarily obscured, either by passing into the shadow of another body or by having another body pass between it and the viewer. Rectilinear propagation is a wave property which states that waves propagate (move or spread out) in straight lines. |
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| 35. |
Pure water is bad conductor of electricity because it is – |
| A. | feebly ionized |
| B. | not volatile |
| C. | a very good solvent |
| D. | a non-polar solvent |
| Answer» A. feebly ionized | |
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Explanation: Pure water is a covalent compound. It exists as simple discrete molecules and have a simple molecular structure. Hence, it does not exist as ions. Therefore, pure water cannot conduct electricity due to the absence of mobile ions and electrons. One instance that water can conduct electricity is when there are dissolved substance in it. Only then will water dissociate into hydrogen ions and hydroxide ions. The presence of mobile ions enables it to conduct electricity. |
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| 36. |
Pycnometer is an instrument used to measure the – |
| A. | Density |
| B. | Intensity of solar radiation |
| C. | Intensity of earthquake |
| D. | High temperatures |
| Answer» A. Density | |
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Explanation: A gas pycnometer is a laboratory device used for measuring the density — or more accurately the volume — of solids, be they regularly shaped, porous or non-porous, monolithic, powdered, granular or in some way comminuted, employing some method of has displacement and the volume-pressure relationship known as Boyle's Law. |
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| 37. |
Lamberts law is related to – |
| A. | Reflection |
| B. | Refraction |
| C. | Interference |
| D. | Illumination |
| Answer» D. Illumination | |
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Explanation: Lambert's Law says that the intensity of emitted light from a surface is directly proportional to the cosine of the angle between the line of view and the normal to the surface. A Lambertian surface is a surface that follows this rule exactly. In practice, most surfaces are not perfectly Lambertian. A surface which obeys Lambert's law is said to be Lambertian, and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle. |
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| 38. |
Rain drops acquire spherical shape due to - |
| A. | viscosity |
| B. | surface tension |
| C. | friction |
| D. | elasticity |
| Answer» B. surface tension | |
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Explanation: The Surface tension pulls the surface of the drop equally at all points thus produces the spherical shape having the minimum surface area. |
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| 39. |
The angular velocity depends upon the rate of change of the _______. |
| A. | Angular Distance |
| B. | Angular acceleration |
| C. | Angular Displacement |
| D. | torque |
| Answer» C. Angular Displacement | |
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Explanation: The angular velocity is defined as the rate of change of angular displacement and is a vector quantity which specifies the angular speed of an object and the axis about which the object is rotating. |
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| 40. |
Coolis tube is used to produce – |
| A. | Radio waves |
| B. | Micro waves |
| C. | X-rays |
| D. | Gama rays |
| Answer» C. X-rays | |
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Explanation: X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered in the late 19th century, and the availability of this controllable source of X-rays created the field of radiography, the imaging of opaque objects with penetrating radiation. |
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| 41. |
Which of the following is used for regulated electric supply? |
| A. | Zener diode |
| B. | Junction diode |
| C. | Gun diode |
| D. | Tunnel diode |
| Answer» A. Zener diode | |
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Explanation: The Zener diode is like a generalpurpose signal diode. When based in the forward direction it behaves just like a normal signal diode, but when a reverse voltage is applied to it, the voltage remains constant for a wide range of currents and hence widely used for regulatedelectric supply. The device was named after Clarence Zener, who discovered this electrical property. Many diodes described as "Zener" diodes rely instead on avalanche breakdown as the mechanism. |
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| 42. |
What is found in frequency modulation? |
| A. | Fixed frequency |
| B. | Fixed dimension |
| C. | Change in frequency and dimension |
| D. | Change in dimension only |
| Answer» A. Fixed frequency | |
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Explanation: Frequency modulation (FM) conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant. Frequency modulation is also used in telemetry, radar, seismic prospecting and newborn EEG seizure monitoring. |
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| 43. |
When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance? |
| A. | four times |
| B. | two times |
| C. | half |
| D. | one-fourth |
| Answer» A. four times | |
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Explanation: Brake force, also known as Brake Power, is a measure of braking power of a vehicle. Suppose a car whose mass is 'x' and is braked from a speed of y km/hr to come to halt at a uniform retardation in z min. If the speed of the car is doubled in the same distance, then the braking force required to stop the car is four times the original speed i.e. '4v'. Note that all the parameters remain to be same. |
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| 44. |
What is the maximum value of deforming force up to which a material shows elastic property and above which the material loses it? |
| A. | Elasticity |
| B. | Strain |
| C. | Elastic Limit |
| D. | Stress |
| Answer» D. Stress | |
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Explanation: The Maximum Extent to which a solid may be stretched without permanent alteration of size or shape. |
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| 45. |
The method of protecting iron from rusting, by coating a thin layer of Zinc is called - |
| A. | Galvanizing |
| B. | rancidity |
| C. | Alloy |
| D. | Pulverizing |
| Answer» A. Galvanizing | |
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Explanation: Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. |
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| 46. |
Ultra violet radiations of the Sun do not reach the earth because, earth's atmosphere is surrounded by – |
| A. | Carbon dioxide |
| B. | Ammonia |
| C. | Chlorine |
| D. | Ozone |
| Answer» D. Ozone | |
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Explanation: The ozone layer absorbs 97-99% of the Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere. In total, ozone makes up only 0.6 parts per million of the atmosphere. |
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| 47. |
"Curie" is unit of : |
| A. | Radioactivity |
| B. | Temperature |
| C. | Heat |
| D. | Energy |
| Answer» A. Radioactivity | |
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Explanation: Curie, in physics, unit of activity of a quantity of a radioactive substance, named in honour of the French physicist Marie Curie. One curie (1 Ci) is equal to 3.7 x 1010 Becquerel (Bq). Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. |
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| 48. |
Speed of sound is the greatest in : |
| A. | Water |
| B. | Air |
| C. | Glass |
| D. | Glycerine |
| Answer» C. Glass | |
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Explanation: Sound travels faster in liquids and non-porous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), than in air at 20 degrees Celsius. |
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| 49. |
Laser is a device to produce - |
| A. | a beam of white light |
| B. | coherent light |
| C. | microwaves |
| D. | X-rays |
| Answer» B. coherent light | |
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Explanation: In physics, two wave sources are perfectly coherent if they have a constant phase difference and the same frequency, and the same waveform. Coherence is an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference. |
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| 50. |
The hydraulic brakes used in automobiles is a direct application of : |
| A. | Archimedes' principle |
| B. | Toricellian law |
| C. | Bernoulli's theorem |
| D. | Pascal's law |
| Answer» D. Pascal's law | |
| Explanation: Pascal's principle guarantees that the pressure is transmitted equally to all parts of the enclosed fluid system. This gives straightline braking unless there is a fluid leak or something to cause a significant difference in the friction of the surfaces. 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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