McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 301. |
Boyle's law is a relationship between – |
| A. | Pressure and volume |
| B. | Volume and temperature |
| C. | Volume and density |
| D. | Pressure and temperature |
| Answer» A. Pressure and volume | |
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Explanation: Boyle's law states that the absolute pressure and volume of a given mass of confined gas are inversely proportional, if the temperature remains unchanged within a closed system. Thus, it states that the product of pressure and volume is a constant for a given mass of confined has as long as the temperature is constant. The law was named after chemist and physicist Robert Boyle, who published the original law in 1662. |
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| 302. |
Flemings right hand rule is used to find the direction of the – |
| A. | Alternate current |
| B. | Direct current |
| C. | Induced current |
| D. | Actual current |
| Answer» C. Induced current | |
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Explanation: Fleming's right hand rule shows the direction of induced current when a conductor moves in a magnetic field. The right hand is held with the thumb, first finger and second finger mutually perpendicular to each other. The rule is named after British engineer John Ambrose Fleming. |
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| 303. |
What is the full form of 'AM' regarding radio broadcasting? |
| A. | Amplitude Movement |
| B. | Anywhere Movement |
| C. | Amplitude Matching |
| D. | Amplitude Modulation |
| Answer» D. Amplitude Modulation | |
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Explanation: AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. An AM receiver detects amplitude variations in the radio waves at a particular frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones. |
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| 304. |
Bar is a unit of which one of the following? |
| A. | Force |
| B. | Energy |
| C. | Pressure |
| D. | Frequency |
| Answer» C. Pressure | |
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Explanation: The bar is a unit of pressure defined as 100 kilopascals. It is about equal to the atmospheric pressure on Earth at sea level. |
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| 305. |
Bolometer is used to measure – |
| A. | Frequency |
| B. | Temperature |
| C. | Velocity |
| D. | Wavelength |
| Answer» B. Temperature | |
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Explanation: A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance. IL was invented in 1878 by the American astronomer Samuel Pierpont Langley. A bolometer consists of an absorptive element, such as a thin layer of metal, connected to a thermal reservoir (a body of constant temperature) through a thermal link. |
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| 306. |
Supersonic plane fly with the speed - |
| A. | less than the speed of sound |
| B. | of sound |
| C. | greater than the speed of sound |
| D. | of light |
| Answer» C. greater than the speed of sound | |
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Explanation: Supersonic travel is a rate of travel of an object that exceeds the speed of sound (Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately 344 m/s, 1,125 ft/s, 768 mph, 667 knots, or 1,235 km/h. |
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| 307. |
If input frequency of a full wave rectifier be n, then output frequency would be- |
| A. | n/2 |
| B. | n |
| C. | 3n/2 |
| D. | 2n |
| Answer» D. 2n | |
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Explanation: The frequency of a full-wave rectifier is double that of the input, if the input is a sine wave. A full-wave rectifier converts the whole of the input waveform to one of constant polarity (positive or negative) at its output. Full- wave rectification converts both polarities of the input waveform to DC (direct current), and yields a higher mean output voltage. |
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| 308. |
Heat transfer horizontally within the atmosphere is called – |
| A. | Conduction |
| B. | Convection |
| C. | Absorption |
| D. | Advection |
| Answer» D. Advection | |
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Explanation: Convection transfers heat vertically into the atmosphere. In order for heat to be transferred to other regions, it must be transferred horizontally by the wind. The horizontal transfer of heat by the wind is called advection. Advection is a transport mechanism of a substance or conserved property by a fluid due to the fluid's bulk motion. An example of advection is the transport of pollutants or silt in a river by bulk water flow downstream. |
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| 309. |
The phenomenon of light associated with the appearance of blue colour of the sky is – |
| A. | Interference |
| B. | Reflection |
| C. | Refraction |
| D. | Scattering |
| Answer» D. Scattering | |
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Explanation: During daylight, the sky appears to be blue because air scatters blue sunlight more than it scatters red. At night, the sky appears to be a mostly dark surface or region scattered with stars. Except for light that comes directly from the sun, most of the light in the day sky is a result of scattering, which is dominated by a small- particle limit called Rayleigh scattering. |
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| 310. |
Air coolers are more suitable for – |
| A. | hot and humid climate |
| B. | hot and dry climate |
| C. | cool and humid climate |
| D. | cool and dry climate |
| Answer» B. hot and dry climate | |
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Explanation: An air cooler works on the simple principle of evaporation. It does not yield good results when humidity is high. On the contrary, the temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation), whichcan cool air using much less energy than refrigeration. |
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| 311. |
Who enunciated the laws of planetary motion? |
| A. | Nicolaus Copernicus |
| B. | Johannes Kepler |
| C. | Isaac Newton |
| D. | Galileo |
| Answer» B. Johannes Kepler | |
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Explanation: Kepler's laws of planetary motion are three scientific laws describing orbital motion, each giving a description of the motion of planets around the Sun. The laws are: the orbit of every planet is an ellipse with the Sun at one of the two foci; a line joining a planet and the Sun sweeps out equal areas during equal intervals of time; and the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. |
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| 312. |
The radiant energy having lowest energy is – |
| A. | gamma rays |
| B. | UV rays |
| C. | visible light |
| D. | microwave radiation |
| Answer» D. microwave radiation | |
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Explanation: The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, Xrays, Ultraviolet light, visible light, infrared light, microwaves, and radio waves. |
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| 313. |
When water is heated from 0°C to 10°C. Its volume |
| A. | increases |
| B. | decreases |
| C. | does not change |
| D. | first decreases and then increases |
| Answer» D. first decreases and then increases | |
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Explanation: 0 |
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| 314. |
A force may change of an object. |
| A. | speed |
| B. | direction |
| C. | shape |
| D. | All options are correct |
| Answer» D. All options are correct | |
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Explanation: 0 |
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| 315. |
Natural radioactivity was discovered by - |
| A. | Marie Curie |
| B. | Ernest Rutherfor |
| C. | Henri Becquerel |
| D. | Enrico Fermi |
| Answer» C. Henri Becquerel | |
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Explanation: The Discovery of Radioactivity. In 1896 Henri Becquerel was using naturally fluorescent minerals to study the properties of x- rays, which had been discovered in 1895 by Wilhelm Roentgen. |
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| 316. |
A circular plate, a cube and a sphere, all made up of same material and having the same mass, are heated to 300°C and left in a room. Which of them will have the slowest rate of cooling? |
| A. | Circular plate |
| B. | Cube |
| C. | Sphere |
| D. | All will cool at the same rate |
| Answer» C. Sphere | |
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Explanation: In the late of 17th century British scientist Isaac Newton studied cooling of bodies. Experiments showed that the cooling rate is approximately proportional to the difference of temperatures between the heated body and the environment. |
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| 317. |
The 'Abolition of Titles' is a fundamental right classified under: |
| A. | Right against Exploitation |
| B. | Right to Freedom |
| C. | Right to equality |
| D. | Right to freedom of religion |
| Answer» C. Right to equality | |
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Explanation: The right to equality includes equality before law, prohibition of discrimination on grounds of religion, race, caste, gender or place of birth, and equality of opportunity in matters of employment, abolition of untouchability and abolition of titles. |
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| 318. |
A player making a long jump is an example of . |
| A. | Projectile motion |
| B. | Rotatory motion |
| C. | Spinning motion |
| D. | Horizontal motion |
| Answer» A. Projectile motion | |
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Explanation: Projectile motion is a form of motion in which an object or particle is thrown near the earth's surface and it moves along a curved path under the action of gravity only. |
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| 319. |
Which of the following is arranged in order of decreasing conductivity? |
| A. | Copper, Aluminium, Steel, Silver |
| B. | Aluminium, Silver, Copper, Steel |
| C. | Copper, Silver, Aluminium, Steel |
| D. | Silver, Copper, Aluminium, Steel |
| Answer» D. Silver, Copper, Aluminium, Steel | |
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Explanation: Copper ; 9% less conductive than silver; aluminium is 10% less conductive than copper; while steel is the least conductive among the given options. The most electrically conductive metal is silver. |
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| 320. |
Which of the following liquids is most viscous? |
| A. | Oil |
| B. | Milk |
| C. | Water |
| D. | petrol |
| Answer» A. Oil | |
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Explanation: Informally, viscosity is the quantity that describes a fluid's resistance to flow. It is dependent on temperature. Viscosityof the different fluids (in cP) is as follows: Edible Oil: 20 to 60; Milk: approximately 1.0; Water: 0.894; and Petrol: around 0.82 to 0.95 cP. |
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| 321. |
Which one of the following has the highest value of specific heat? |
| A. | Glass |
| B. | Copper |
| C. | Lead |
| D. | Water |
| Answer» D. Water | |
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Explanation: The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C which is higher than any other common substance. As a result, water plays a very important role in temperature regulation. The specific heat per gram for water is much higher than that for a metal. |
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| 322. |
When hot-water is sprinkled on a hotter glass tumbler, it breaks because – |
| A. | glass suddenly expands |
| B. | glass suddenly contracts |
| C. | water evaporates |
| D. | glass reacts chemically with water |
| Answer» B. glass suddenly contracts | |
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Explanation: If the poured liquid is relatively hotter or colder in comparison to the tumbler, it will break. When hot water is poured into a tumbler there is an uneven increase in the thermal expansion of the walls of the vessel. |
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| 323. |
Electricity is transmitted over long distances – |
| A. | it is fast |
| B. | there is less wastage of energy |
| C. | it is safer |
| D. | it is cheaper |
| Answer» B. there is less wastage of energy | |
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Explanation: Long distance means higher wastage of energy. So High volt direct-current(HVDC) technology is used forgreater efficiency in very long distances. Electricity is transmitted at high voltages (110 kV or above) to reduce the energy lost in long-distance transmission. |
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| 324. |
If in a motion, the axis of the rotation passes through an object, then the motion is called. |
| A. | Orbital motion |
| B. | Circulatory motion |
| C. | Spin motion |
| D. | Oscillatory motion |
| Answer» C. Spin motion | |
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Explanation: A rotation is a circular movement of an object around a center (or point) of rotation A threedimensional object al ways rotates around an imaginary line called a rotation axis. |
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| 325. |
Of the following properties of a wave, the one that is independent of the other is its |
| A. | amplitude |
| B. | velocity |
| C. | wavelength |
| D. | frequency |
| Answer» A. amplitude | |
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Explanation: The maximum extent of a vibration or oscillation, measured from the position of equilibrium. |
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| 326. |
Noise is measured in – |
| A. | Watt |
| B. | REM |
| C. | Centigrade |
| D. | Decibel |
| Answer» D. Decibel | |
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Explanation: The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. 230. (4) Bats use echolocation to navigate and forage, often in total darkness. They generally emerge from theirroosts in caves, attics, or trees at dusk and hunt for insects into the night. |
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| 327. |
If ice floating on water in a vessel melts, the water level in the vessel . |
| A. | increases |
| B. | does not change |
| C. | first increases before decreasing |
| D. | decreases |
| Answer» B. does not change | |
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Explanation: When ice floating on water in a vessel melts, the water level in the vessel does not change. This is because when floating, the ice displaces an amount of water equal to its mass, and when melted, it becomes an amount of water equal to its mass. |
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| 328. |
ATM stands for – |
| A. | Automatic Teller Machine |
| B. | Automated Teller Machine |
| C. | Automatic Tally Machine |
| D. | Automated Tally Mechanism |
| Answer» A. Automatic Teller Machine | |
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Explanation: An automated teller machine or automatic teller machine (ATM) is a computerized telecommunications device that provides the clients of a financial institution with access to financial transactions in a public space without the need for a cashier, human clerk or bank teller. ATMs are known by various other names including Arm machine, automated banking machine, "cash dispenser" (Germany) and various regional variants derived from trademarks on ATM systems held by particular banks. |
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| 329. |
The first synthetic fibre made by man was- |
| A. | Rayon |
| B. | Nylon |
| C. | Polyester |
| D. | Terycott |
| Answer» B. Nylon | |
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Explanation: Nylon, the first synthetic fiber in the "fully synthetic" sense of that term, was developed by Wallace Carothers, an American researcher at the chemical firm DuPont in the 1930s. |
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| 330. |
Compared to fresh Water, the freezing point of sea water is - |
| A. | Higher |
| B. | Lower |
| C. | Same |
| D. | Depends on the sea from which the water is sourced |
| Answer» B. Lower | |
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Explanation: Ocean water freezes just like freshwater, but at lower temperatures. |
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| 331. |
Which colour is the complementary colour of yellow? |
| A. | Blue |
| B. | Green |
| C. | Orange |
| D. | Red |
| Answer» A. Blue | |
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Explanation: Complementary colours are pairs of colours that are of "opposite" hue in some colour model. In colour theory, two colours are called complementary if, when mixed in the proper proportion, they produce a neutral colour (grey, white, or black). In roughly-perceptual colour models, the neutral colours (white, grey, and black) lie along a central axis. |
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| 332. |
Which of the following produces more severe burns? |
| A. | Boiling water |
| B. | Hot water |
| C. | Steam |
| D. | Melting Iceberg |
| Answer» C. Steam | |
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Explanation: A burn is an injury to the body's tissue resulting from heat, chemicals, electricity or sunlight. Burns are often classified as first degree (those causing damage to the outer layerof the skin, the epidermis), second degree (causing deeper damage to the dermis, the layer beneath the epidermis), third degree (those causing the deepest and most severe damage destruction of all layers of the skin and damage to tissues underneath. |
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| 333. |
The sudden fall of atmospheric pressure indicates – |
| A. | fair weather |
| B. | storm |
| C. | rain |
| D. | cold weather |
| Answer» B. storm | |
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Explanation: Atmospheric pressure is basically the weight of air in the atmosphere above the reservoir, so the level of mercury continues to change until the weight of mercury in the glass tube is exactly equal to the weight of air above the reservoir. |
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| 334. |
The energy emitted by the Sun is due to |
| A. | Chemical reaction |
| B. | Nuclear fission |
| C. | Nuclear fusion |
| D. | All of the above |
| Answer» C. Nuclear fusion | |
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Explanation: The spectrum of the Sun's solar radiation is close to that of a black body with a temperature of about 5,800 K. The Sun emits Electromagnetic radiation across most of the electromagnetic spectrum. Although the Sun produces Gamma rays as a result of the nuclear fusion process, these super high energy photons are converted to lower energy photons before they reach the Sun's surface and are emitted out into space. |
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| 335. |
The sky appears blue because of – |
| A. | Atmospheric water vapour |
| B. | Scattering of light |
| C. | Reflection on sea water |
| D. | Emission of blue wavelength by the sun |
| Answer» B. Scattering of light | |
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Explanation: The sky is blue because the molecules in the air scatter light in the higher wavelengths (that is, the blue light), while lower wavelength light (that is, the light on the red end of the spectrum) goes through to the ground. So the light that get finally reflected down from the scattering is blue, therefore a blue sky. This is called Rayleigh scattering. |
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| 336. |
The metal whose electrical conductivity is more, is – |
| A. | copper |
| B. | aluminium |
| C. | silver |
| D. | lead |
| Answer» C. silver | |
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Explanation: Copper ; 9% less conductive than silver: aluminium is 1 0% less conductive than copper; while steel is the least conductive among the given options. The most electrically conductive metal is silver. |
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| 337. |
What happens to a liquid, when the vapour pressure equals the atmospheric pressure? |
| A. | The liquid cools |
| B. | The liquid boils |
| C. | No change |
| D. | The liquid evaporates |
| Answer» B. The liquid boils | |
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Explanation: Ordinary evaporation is a surface phenomenon -since the vapor pressure is low and since the pressure inside the liquid is equal to atmospheric pressure plus the liquid pressure, bubbles of water vapor cannot form. But at the boiling point, the saturated vapor pressure is equal to atmospheric pressure, bubbles form, and the vaporization becomes a volume phenomena. |
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| 338. |
Why do brads not have respiratory trouble at the time of flying at high all? |
| A. | Their lungs are very large |
| B. | They fly inactively |
| C. | They have extra air sacs |
| D. | They use less |
| Answer» C. They have extra air sacs | |
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Explanation: The avian respiratory system delivers oxygen from the air to the tissues and also removes carbon dioxide. In addition, the respiratory system plays an important role in thermoregulation (maintaining normal body temperature). The avian respiratory system is different from that of other vertebrates, with birds having relatively small lungs plus nine air sacs that play an important role in respiration (but are not directly involved in the exchange of gases). |
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| 339. |
The temperature which has the same reading on both Fahrenheit and Celsius scales is – |
| A. | 40° |
| B. | -40° |
| C. | -34° |
| D. | -140' |
| Answer» B. -40° | |
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Explanation: If C is the temperature in Celsius and F is the temperature in Fahrenheit then, C/S = (F-32)/9. They are equal at -40° (minus 40 degrees), because if we convert the readings of Celsius and Fahrenheit, we will have: Celsius to Fahrenheit (-40°C x 9/5) +32 = -72 + 32 = -40°F. Fahrenheit to Celsius (-40°F - 32°) x 5/9 = (-72) x 5/9 = -40°C. |
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| 340. |
Kilowatt-hour is the unit of : |
| A. | Energy |
| B. | Power |
| C. | Force |
| D. | Momentum |
| Answer» A. Energy | |
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Explanation: The kilowatt hour, or kilowatt- hour, is a unit of energy equal to 1000 watt hours or 3.6 mega-joules For constant power, energy in watt hours is the product of power in watts and time in hours. The kilowatt hour is most commonly known as a billing unit for energy delivered to consumers by electric utilities. |
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| 341. |
In nuclear reactor, heavy water is used as – |
| A. | coolant |
| B. | fuel |
| C. | moderator |
| D. | atomic smasher |
| Answer» C. moderator | |
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Explanation: Heavy water is used in certain types of nuclear reactors where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile uranium-235 than with uranium-238 which captures neutrons without fissioning. Because they do not require uranium enrichment, heavy water reactors are of concern in regards to nuclear proliferation. |
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| 342. |
Tear gas used by the police to disperse the mob contains – |
| A. | carbon dioxide |
| B. | chlorine |
| C. | ammonia |
| D. | hydrogen sulphide |
| Answer» B. chlorine | |
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Explanation: Tear gas is a compound. Each molecule of tear gas contains one atom of chlorine. The compound 2- chlorobenzalmalononitrile, a cyanocarbon, is the defining component of a "tear gas" commonly referred to as CS gas, which is used as a riot control agent. |
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| 343. |
Mist is caused by – |
| A. | dry ice |
| B. | ice at low temperature |
| C. | water vapour at low temperature |
| D. | carbon-monoxide in solid form |
| Answer» C. water vapour at low temperature | |
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Explanation: Mist is a phenomenon caused by small droplets of water suspended in air. It can occur as part of natural weather or volcanic activity, and is common in cold air abovewarmer water, in exhaled air in the cold, and in a steam room of a sauna. It can also be created artificially with aerosol canisters if the humidity conditions are right. The only difference between mist and fog is visibility. |
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| 344. |
The ozone layer in the atmosphere is at a height of about . |
| A. | 25 km |
| B. | 50 km |
| C. | 100 km |
| D. | 200 km |
| Answer» B. 50 km | |
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Explanation: Ozone is mainly found in two regions of the Earth's atmosphere. Most ozone (about 90%) resides in a layer that begins between 10 to 17 kilometers above the Earth's surface and extends up to about 50 kilometers |
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| 345. |
The part of the eye having the larges refractive index is : |
| A. | cornea |
| B. | aqueous humor |
| C. | lens |
| D. | vitreous humor |
| Answer» C. lens | |
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Explanation: The cornea represents the strongest part of the refracting power of the eye, providing about 80% of the power of the system. The index of refraction of the cornea is about 1.376. Rays pass from the cornea into the watery fluid known as the aqueous humor which has an index of refraction of about 1.336. |
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| 346. |
Conversion of heat into electrical er is achieved by using – |
| A. | Ammeter |
| B. | Hydrometer |
| C. | Voltmeter |
| D. | Thermocouple |
| Answer» D. Thermocouple | |
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Explanation: Thermoelectric generators convert thermal energy into electricity by using heat from the body — or any object with a temperature gradient — as their energy source.At the heart of every thermoelectric generator is an array of thermocouples that are responsible for converting thermal energy into electricity. Bismuth telluride and its alloys are commonly used in thermocouples. |
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| 347. |
The filament of electric bulb is made of |
| A. | Iron |
| B. | Nichrome |
| C. | Tungsten |
| D. | Graphite |
| Answer» C. Tungsten | |
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Explanation: The filament is the part of the light bulb that produces light. Filaments in incandescent light bulbs are made of tungsten. |
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| 348. |
Necessary element of change in solar energy to electric energy – |
| A. | Berilliurn |
| B. | Silicon |
| C. | Tantelum |
| D. | Pure Copper |
| Answer» B. Silicon | |
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Explanation: A small solar electric or photovoltaic (PV) converts solar energy into electrical energy. Solar cells consist of semiconductor materials which work on photoelectric effect. Silicon remains the most popular material for solar cells. |
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| 349. |
Electric current in a metal wire is due to the flow of — |
| A. | Electrons |
| B. | Protons |
| C. | Ions |
| D. | Holes |
| Answer» A. Electrons | |
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Explanation: A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor. The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field. |
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| 350. |
Which type of reaction produces the most harmful radiation? |
| A. | Fusion reaction |
| B. | Fission reaction |
| C. | Chemical reaction |
| D. | Photo-Chemical reaction |
| Answer» B. Fission reaction | |
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Explanation: Radiation is one of the byproducts of radioactive decay of unstable atomic nuclei. Nuclear fission is the process on which the operation of most nuclear power plants is based. When certain nuclei (for example that of uranium-235) are bombarded with neutrons, the nucleus splits into two smaller nuclei of roughly (though not exactly) equal sizes. |
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