McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: General Knowledge (GK) .
| 1001. |
On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because |
| A. | Mercury is a metal |
| B. | Density of mercury is greater than that of water |
| C. | Cohesion of mercury is greater than its adhesion with glass |
| D. | Cohesion of water is greater than its adhesion with glass |
| Answer» C. Cohesion of mercury is greater than its adhesion with glass | |
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Explanation: When liquid is placed on a smooth surface like glass plate, the relative strengths of the cohesive and adhesive forces acting on that liquid determine the shape it will take (and whether or not it will wet the surface). If the adhesive forces between a liquid and a surface are stronger, they will pull the liquid down, causing it to wet the surface. |
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| 1002. |
The mass-energy relation is the outcome of – |
| A. | quantum theory |
| B. | general theory of relativity |
| C. | field theory of energy |
| D. | special theory of relativity |
| Answer» D. special theory of relativity | |
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Explanation: Special theory of relativity postulates that the speed of light is a universal constant. We cannot reach speeds greater than the speed of light by the relativistic addition of velocities. |
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| 1003. |
Which set of conditions represents the easiest way to liquiify a gas? |
| A. | Low temperature and high pressure |
| B. | High temperature and low pressure |
| C. | Low temperat.ure and low pressure |
| D. | High temperature and high pressure |
| Answer» A. Low temperature and high pressure | |
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Explanation: Low temperature and high pressure set of conditions represents the easiest way to liquefy a gas. Liquefaction of gases is physical conversion of a gas into a liquid state (condensation). The processes are used for scientific, industrial and commercial purposes. Many gases can be put into a liquid state at normal atmospheric pressure by simple cooling; a few, such as carbon dioxide, require pressurization as well. |
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| 1004. |
A person can jump higher on the moon's surface than on the earth because – |
| A. | the moon's surface is rough |
| B. | the acceleration due to gravity in moon is smaller than that on the earth. |
| C. | the moon is cooler than earth |
| D. | the moon has no atmosphere |
| Answer» B. the acceleration due to gravity in moon is smaller than that on the earth. | |
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Explanation: The acceleration due to the gravitational field of moon (g' = 1.62631 ms-2) is one-sixth of the acceleration due to gravity on the Earth. So the weight of the same body is also 1/6th on moon in comparison to that on the surface of the earth. It is due to this reason; a man can jump six times higher on moon than on earth. |
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| 1005. |
Rectifiers are used to convert - |
| A. | Direct current to Alternating current |
| B. | Alternating current to Direct current |
| C. | high voltage to low voltage |
| D. | low voltage to high voltage |
| Answer» B. Alternating current to Direct current | |
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Explanation: Converting DC power from one voltage to another is much more complicated. One method of DC-to-DC conversion first converts power to AC (using a device called an inverter), then uses a transformer to change the voltage, and finally rectifies power back to DC. |
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| 1006. |
A dynamo is used to convert – |
| A. | mechanical energy into electrical energy |
| B. | electrical energy into mechanical energy |
| C. | electrical energy into magnetic energy |
| D. | magnetic energy into mechanical energy |
| Answer» A. mechanical energy into electrical energy | |
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Explanation: A dynamo converts mechanical energy into electrical energy by taking advantage of a phenomenon known as electromagnetic induction. It is an electric generator that is similar to those that provide electricity to our homes. |
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| 1007. |
Absolute Zero is defined as – |
| A. | The temperature at which all molecular motion ceases |
| B. | At which water boils at 298K |
| C. | At which liquid Helium boils |
| D. | At which the volume becomes zero |
| Answer» A. The temperature at which all molecular motion ceases | |
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Explanation: Absolute zero is the temperature at which all motion in matter stops and is thought to be unreachable. It is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. |
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| 1008. |
When a ring of metal is heated what happens to its hole? |
| A. | expands |
| B. | contracts |
| C. | it expands or contracts according to its diameter |
| D. | it expands or contracts according to its coefficient of expansion |
| Answer» A. expands | |
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Explanation: The hole size will increase because in expansion the size between two molecules, do not increase so when the molecules on the outer edge move outward. Due to expansion, the size of the hole will also increase so as to compensate the distance change between the molecules. Thermal expansion is the tendency of matter to change in volume in response to a change in temperature. |
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| 1009. |
Red is used as an emergency or danger signal as – |
| A. | it is a striking colour |
| B. | its wavelength is the longest |
| C. | it is scattered |
| D. | it has very high energy |
| Answer» B. its wavelength is the longest | |
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Explanation: The effect of scattering is inversely related to the fourth power of the wavelength of a colour. Red has the highest wavelength of all the colours and is able to travel the longest distance through fog, rain, and the alike. |
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| 1010. |
The dynamo converts – |
| A. | mechanical energy into electrical energy |
| B. | electrical energy into mechanical energy |
| C. | mechanical energy into magnetic energy |
| D. | magnetic energy into mechanical energy |
| Answer» A. mechanical energy into electrical energy | |
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Explanation: 0 |
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| 1011. |
A small drop of oil spreads over water because : |
| A. | oil has a higher surface tension |
| B. | water has a higher surface tension |
| C. | oil has a higher viscosity |
| D. | water has a higher viscosity |
| Answer» B. water has a higher surface tension | |
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Explanation: Dispersion is used to separate a beam of white light into its constituent spectrum of colours. This phenomenon leads to rainbow. |
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| 1012. |
A small gap is left at the joints of rails in a railway track to – |
| A. | avoid the tracks being distorted due to seasonal temperature variation |
| B. | avoid the heating of tracks to high temperature |
| C. | control the speed of train |
| D. | keep the rails equidistant |
| Answer» A. avoid the tracks being distorted due to seasonal temperature variation | |
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Explanation: A small gap is left at the joints of rails in a railway track to provide space for the expansion of rail pieces when the temperature rises during summer. |
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| 1013. |
Which of the following criterion is used for any metal to be used as a cooking material? |
| A. | More specific heat |
| B. | More thermal conductivity |
| C. | Less thermal conductivity |
| D. | Less electrical conductivity |
| Answer» C. Less thermal conductivity | |
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Explanation: A metal to be used as a cooking material should have less thermal conductivity. |
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| 1014. |
Super conductors are substances that – |
| A. | offer minimum resistance to flow of electric current |
| B. | conduct electricity at low temperature |
| C. | conduct electricity at high temperature |
| D. | offer high resistance to the flow of electric current |
| Answer» A. offer minimum resistance to flow of electric current | |
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Explanation: A superconductor is a material that can conduct electricity or transport electrons from one atom to another with no resisttance. Noheat, sound or any other form of energy is released from the material when it reaches the temperature at which it becomes superconductive. |
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| 1015. |
Cloudy nights are wanner compared nights, because clouds mainly – |
| A. | Absorb heat from the atmosphere send it towards earth |
| B. | Prevent cold waves from the sky descending on earth |
| C. | Reflect back the heat given by earth |
| D. | Produce heat and radiate it toward earth |
| Answer» C. Reflect back the heat given by earth | |
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Explanation: It is because the night side of Earth will radiate infra-red radiation (heat) back into space. When there is cloud cover, the clouds act like a blanket and trap the heat close to the ground just like a blanket traps heat close to our body. |
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| 1016. |
Kepler's law of planetary motion states that the square of the time period is proportional to the – |
| A. | semi-major axis |
| B. | square of the semi-major axis |
| C. | cube of the semi-major axis |
| D. | fourth power of the serni-major axis |
| Answer» C. cube of the semi-major axis | |
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Explanation: Kepler's law of planetary motion states that the square of the time period is proportional to the cube of the semi-major axis. |
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| 1017. |
Spring tides occur when: |
| A. | the moon, the sun and the earth are in the same line |
| B. | the sun is closest to earth |
| C. | the moon is farthest from earth |
| D. | the earth is at right angles with the sun and the moon |
| Answer» A. the moon, the sun and the earth are in the same line | |
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Explanation: The combined tide raising forces of the Moon and the Sun are at their greatest effect when the Sun and the Moon are in line with the Earth. |
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| 1018. |
When a ship enters the sea from a river |
| A. | It rises a little |
| B. | It sinks a little |
| C. | It remains at the same level |
| D. | It rises or sinks depending on the material it is made of |
| Answer» A. It rises a little | |
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Explanation: On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, or 599 mM). Seawater is denser than hot fresh water and pure water (density 1.0 g/ml) because the dissolved salts add mass without contributing significantly to the volume. |
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| 1019. |
Why are we able to hear short wave broadcasts better than long wave broadcasts? |
| A. | Short waves are more energetic than long waves |
| B. | Short waves are unaffected by atmospheric disturbances |
| C. | Short wave broadcasts are made by nearby radio stations |
| D. | By convention, short waves are meant for long distances, whereas long waves are reserved for short distances |
| Answer» A. Short waves are more energetic than long waves | |
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Explanation: Shortwave radio is used for broadcasting of voice and music, and long- distance communication to ships and aircraft, or to remote areas out of reach of wired communication or other radio services and that's why it is more energetic than long waves. |
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| 1020. |
In severe winter, in cold countries water pipes burst because – |
| A. | Water expands on freezing |
| B. | Contraction of water pipes |
| C. | High atmospheric pressure |
| D. | Combined effect of all the above three |
| Answer» A. Water expands on freezing | |
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Explanation: Most liquids have a quite simple behavior when they are cooled (at a fixed pressure): they shrink. The liquid contract as it is cooled; because the molecules are moving slower they are less able to overcome the attractive intermolecular forces drawing them closer to each other. Then the freezing temperature is reached, and the substance solidifies, which causes it to contract some more because crystalline solids are usually tightly packed. |
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| 1021. |
A television channel is characterized by |
| A. | frequency of transmitted signal |
| B. | velocity of transmitted signal |
| C. | physical dimension of television screen |
| D. | size of picture tube |
| Answer» A. frequency of transmitted signal | |
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Explanation: A television channel is a physical or virtual channel over which a television station or television network is distributed. Channel numbers represent actual frequencies used to broadcast the television signal. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video (VSB) and 59.75 MHz for analog audio (FM), or 55.31 MHz for digital ATSC (8VSB). |
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| 1022. |
Which one of the following not a feature of Indifference Curve? |
| A. | They do not intersect each other |
| B. | They slope downwards to the right |
| C. | They are parallel to each other |
| D. | They are concave to each other |
| Answer» D. They are concave to each other | |
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Explanation: Indifference curves are usually convex to the on-gin. In In other words, the indifference curve is relatively flatter in its right- hand portion and relatively steeper in its left- hand portion. The degree of convexity of anindifference curve depends on the rate of fall in the marginal rate of substitution. |
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| 1023. |
Heat energy of an object is - |
| A. | The average energy of the molecules of the object |
| B. | The total energy of the molecules of the object |
| C. | The average velocity of the molecules of the object |
| D. | The average P.E. of the molecules of the object |
| Answer» B. The total energy of the molecules of the object | |
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Explanation: The transfer or flow due to the difference in temperature between the two objects is called heat. Heat energy of an object is the total energy of the molecules of the object. |
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| 1024. |
If a body moves with a constant speed in a circle – |
| A. | no work is done on it |
| B. | no force acts on it |
| C. | no acceleration is produced in it |
| D. | its velocity remains constant |
| Answer» D. its velocity remains constant | |
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Explanation: A body moving with a constant speed in a circle is an example of uniform circular motion. The velocity vector is constant in magnitude but changing in direction. Since velocity is a vector quantity that has both magnitude and direction, a change in either the magnitude or the direction constitutes a change in the velocity which leads to change in acceleration. |
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| 1025. |
A white and smooth surface is – |
| A. | good absorber and good reflector of heat |
| B. | bad absorber and good reflector of heat |
| C. | good absorber and bad reflector of heat |
| D. | bad absorber and bad reflector of heat |
| Answer» B. bad absorber and good reflector of heat | |
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Explanation: Shiny surfaces are poor absorbers of heat radiation and the best reflectors of heat radiation. Black surfaces are the best emitters and best absorber of heat radiation. |
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| 1026. |
It is easier for a man to swim in sea water, than in river water because – |
| A. | the density of sea water is lesser than the density of river water |
| B. | the density of sea water is more than the density of river water |
| C. | the sea is deeper than the river |
| D. | the sea is wider than the river |
| Answer» B. the density of sea water is more than the density of river water | |
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Explanation: the density of sea water is more than the density of river water |
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| 1027. |
In the pressure cooker, cooking is faster because the increase in vapour pressure - |
| A. | increase the specific heat |
| B. | decreases the specific heat |
| C. | decreases the boiling point |
| D. | increases the boiling point |
| Answer» D. increases the boiling point | |
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Explanation: 0 |
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| 1028. |
Kinetic energy depends on – |
| A. | the velocity or speed of the moving body. |
| B. | the mass of the moving body |
| C. | the pressure of the moving body |
| D. | both mass and velocity of the moving body |
| Answer» D. both mass and velocity of the moving body | |
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Explanation: Kinetic energy is the energy associated with the movement of objects. The amount of kinetic energy that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object. |
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| 1029. |
The apparent weight of a man in a lift is less the real weight when – |
| A. | the lift is going up with an acceleration |
| B. | the lift is going down with uniform speed |
| C. | the lift is going up with uniform speed |
| D. | the lift is going down with an acceleration |
| Answer» D. the lift is going down with an acceleration | |
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Explanation: If the lift accelerates downwards with acceleration a, then the apparent weight of the man standing in the lift will be less than the true weight of the man by an amount ma. On the contrary, if the lift accelerates upwards with acceleration, then the apparent weight of the man will be greater than his true weight. |
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| 1030. |
The passengers standing in a bus fall in the backward direction when the stationary bus begins to move. Which of the following laws explains this situation? |
| A. | Newton's First Law of Motion |
| B. | Newton's Third Law of Motion |
| C. | Newton's Second Law of Motion |
| D. | The Law of Conservation of Momentum |
| Answer» A. Newton's First Law of Motion | |
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Explanation: According to Newton's first law of motion (law of inertia) a body either at rest or in uniform motion will remain so unless acted on by a force When the passengers are standing on the bus, they (and the bus) are in a state of uniform motion. |
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| 1031. |
Plants are dried up in winter due to frost because – |
| A. | Evaporation does not take place |
| B. | Photosynthesis does not take place at such low temperature |
| C. | Respiration does not take place at low temperature |
| D. | There is mechanical loss of tissues and drought condition prevails |
| Answer» D. There is mechanical loss of tissues and drought condition prevails | |
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Explanation: Respiration does not rely on the sun, so it is possible for plants to respire around the clock. The rate of respiration is dependent on temperature: The warmer it is, the more a plant will respire. Drought, extreme winter or frost and heat injury all create a situation for the plant where moisture is not adequate to maintain the proper water levels in plant tissues. Extreme winter cold and frost are similar to summer drought in that frozen water is unavailable to the plant. The air is very dry as well. |
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| 1032. |
Radio telescopes are better than optical telescopes because - |
| A. | they can detect faint galaxies which no optical telescope can |
| B. | they can work even in cloudy conditions |
| C. | they can work during the day and night |
| D. | All of the above |
| Answer» D. All of the above | |
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Explanation: 0 |
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| 1033. |
White clothes are cooler than black ones because they – |
| A. | absorb all the light that reaches them |
| B. | reflect all the light that reaches them |
| C. | will not allow the light to penetrate |
| D. | cool the sunlight completely |
| Answer» B. reflect all the light that reaches them | |
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Explanation: The coolness and warmth associated with clothes is because of their reflective or absorptive capacities. White clothes are good reflectors of light, thereby keeping the body cool. The opposite is the case with black clothes. |
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| 1034. |
Sound is heard over longer distances on rainy days because – |
| A. | sound travels slowly in moist air |
| B. | sound travels faster in moist air |
| C. | moist air does not absorb sound |
| D. | moist air absorbs sound |
| Answer» B. sound travels faster in moist air | |
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Explanation: The speed of sound in a medium is inversely proportional to the square root of its density. Higher is the humidity in the air, greater will be the velocity of sound. Therefore, the speed of sound in moist air is more than that in dry air. This is why the sirens of mills, whistle of trains and others are heard up to longer distances on a rainy day than on a dry day. |
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| 1035. |
A galvanometer can be converted to a voltmeter by connecting – |
| A. | a high resistance in parallel |
| B. | a high resistance in series |
| C. | a low resistance in series |
| D. | a low resistance in parallel |
| Answer» B. a high resistance in series | |
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Explanation: In order to convert a Galvanometer into voltmeter, a very high resistance known as "series resistance" is connected in series with the galvanometer. The con-version is made for enabling the galvanometer to measure the potential difference across any component in a circuit. |
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| 1036. |
Copper wires are generally used for electrical power transmission instead of iron wire because |
| A. | copper is cheaper than iron |
| B. | copper is lighter than iron |
| C. | copper is a better conductor of electricity than iron |
| D. | copper can take higher power than iron |
| Answer» C. copper is a better conductor of electricity than iron | |
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Explanation: Copper is generally preferred for electrical power transmission instead of iron because of its high electrical conductivity and low resistivity. |
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| 1037. |
The natural environment refers to - |
| A. | The living organisms and non-living objects or factors in an area undisturbed by human activity |
| B. | The atmosphere in a forest |
| C. | The plants and animals in a forest |
| D. | The atmosphere of an area-a forest, lake or an ocean |
| Answer» A. The living organisms and non-living objects or factors in an area undisturbed by human activity | |
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Explanation: 0 |
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| 1038. |
Rainbows are produced when sunlight |
| A. | Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction |
| B. | Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection. |
| C. | Incident on raindrops hanging in the atmosphere is dispersed after suffering reflection. |
| D. | None of the given statements is correct. |
| Answer» B. Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection. | |
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Explanation: When the light rays from the Sun are incident on water drops hanging in the atmosphere; these rays are dispersed into seven colours of white light and internally reflected by the drops. This dispersion and internal reflection results in production of colour arcs which appear hanging in the sky and known as rainbow. |
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| 1039. |
The information of brilliant colors in a thin soap film is a consequence of the phenomena of - |
| A. | Polarization and interference |
| B. | Diffraction and dispersion |
| C. | Multiple refraction and dispersion |
| D. | Multiple reflection and interference |
| Answer» D. Multiple reflection and interference | |
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Explanation: Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light. |
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| 1040. |
Purpose of an optical filter is to – |
| A. | reflect lights of different colours |
| B. | dispense light into component colours |
| C. | refract light of different colours |
| D. | transmit or absorb light of different colours |
| Answer» D. transmit or absorb light of different colours | |
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Explanation: Optical filters are devices that selectively transmit light in a particular range of wavelengths, that is, colors, while blocking the remainder. They are commonly used in photography (where some special effect filters are occasionally used as well as absorptive filters), fluorescence microscopy, spectroscopy, clinical chemistry, colour stage lighting, etc. |
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| 1041. |
Why are covalent compounds poor conductors of electricity? |
| A. | Due to the presence of charged particles. |
| B. | Due to the absence of charged particles. |
| C. | Due to the presence of a triple bond. |
| D. | None of the above |
| Answer» B. Due to the absence of charged particles. | |
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Explanation: In a covalent compound, electrons are shared between atoms. This leaves no free electrons and hence there and no charged particles. This leads to covalent compounds being poor conductors of electricity. |
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| 1042. |
Which of the following is not correct? |
| A. | Ammeter measures the strength of electric current. |
| B. | Lactometer measures the relative density of milk. |
| C. | Rain gauge measures rain fall |
| D. | Hygrometer measures sound under water. |
| Answer» D. Hygrometer measures sound under water. | |
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Explanation: A hygrometer is a weather instrument used to measure the amount of humidity in the atmosphere |
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| 1043. |
Which one of the following processes is responsible for the glittering of air bubble rising through water? |
| A. | Reflection of light |
| B. | Refraction of light |
| C. | Total internal reflection of light |
| D. | Scattering of light |
| Answer» C. Total internal reflection of light | |
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Explanation: Total internal reflection is responsible for glittering which occurs when the light from a denser media (liquid) tries to enter less dense media (air in bubble). This reflected light when captured by our eyes is seen as glittering. |
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| 1044. |
Railway tracks are banked on curves so that : |
| A. | the train may not fall down inwards. |
| B. | the weight of the train may be reduced. |
| C. | necessary centripetal force may be obtained from the horizontal component of the normal reaction due to track. |
| D. | no frictional force may be produced between the wheels and the track. |
| Answer» C. necessary centripetal force may be obtained from the horizontal component of the normal reaction due to track. | |
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Explanation: A vehicle moving at a fast speed on a straight rail/ road has a large inertia, i.e. tendency to keep moving in the same direction at the same speed. When it takes a circular turn on a curved rail/road, it experiences an additional force, termed as centripetal force, acting towards the centre of the circle. |
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| 1045. |
An electron microscope gives higher magnifications than an optical microscope because – |
| A. | The velocity of electrons is smaller than that of light |
| B. | The wavelength of electrons is smaller as compared to the wavelength of visible light |
| C. | The electrons have more energy than the light particulars |
| D. | The electron microscope uses more powerful lenses |
| Answer» B. The wavelength of electrons is smaller as compared to the wavelength of visible light | |
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Explanation: An electron microscope is a microscope that uses a beam of acceleratedelectrons as a spume of illumination. Becalise the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, the electron microscope has a higher resolving power than a light microscope and can reveal the structure of smaller objects. |
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| 1046. |
Nichrome wire is used in an electric heater because . |
| A. | It has high resistance |
| B. | It has high melting point |
| C. | It can resist a current upto approx 5 amperes |
| D. | For all of the above reasons |
| Answer» D. For all of the above reasons | |
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Explanation: 0 |
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| 1047. |
Out of the following pairs, which one does not have identical dimension? |
| A. | Moment of inertia and moment of a force |
| B. | Work and Torque |
| C. | Angular momentum and Planck's constant |
| D. | Impulse and Momentum |
| Answer» A. Moment of inertia and moment of a force | |
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Explanation: 0 |
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| 1048. |
A concave lens always forms – |
| A. | a real image |
| B. | a virtual image |
| C. | an Image type which depends on object characteristics |
| D. | an image type which depends on lens curvature |
| Answer» B. a virtual image | |
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Explanation: Concave lens always form the virtual and erect image and the image is always diminished. Convex lens forms real image as well as virtual image. It forms both enlarged image and the diminished image. |
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| 1049. |
Ondometer is a - |
| A. | Measuring instrument for distance covered by motor wheels |
| B. | Measuring instrument for frequency of electromagnetic waves |
| C. | Device for measuring sound intensity |
| D. | Measuring instrument for electric power |
| Answer» B. Measuring instrument for frequency of electromagnetic waves | |
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Explanation: 0 |
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| 1050. |
Specific gravity is defined as the ratio of – |
| A. | density of the substance to the density of water |
| B. | density of the substance to the density of water at 0°C |
| C. | density of water at 4°C to the density of the substance |
| D. | density of the substance to the density of water at 4°C |
| Answer» A. density of the substance to the density of water | |
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Explanation: Specific gravity is the ratio of the density of a substance to the density (mass of the same unit volume) of a reference substance. The reference substance is nearly always water for liquids or air for gases. |
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