Tiêu đề Static GK MCQs(English)-Rekib.pdf ✅

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Physics (Set: 01) Q.1) A light year is a measure of : (1) Speed (2) Velocity (3) Distance (4) Time Correct Answer – (3) Distance 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 light- year is a measure of distance (rather than, as is sometimes misunderstood, a measure of time). Q.2) A device which is used to limit the current in an electrical circuit is called a - (1) Grid (2) Fuse (3) Hub (4) Conductor Correct Answer – (2) Fuse 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. Q.3) Two rods, one of copper and other of steel, experience the same up thrust when placed in water. Thus, both have – (1) equal volume (2) equal weight (3) equal density (4) equal mass Correct Answer – (1) equal volume 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. Q.4) Minimum numbers of unequal vectors which can give zero resultant are - (1) Two (2) Three (3) Four (4) More than four Correct Answer – (2) three Explanation: Minimum number of unequal vectors which can give three zero resultants. Q.5) Water is not suitable as a calorimetric substance because it – (1) has high specific heat (2) is a good conductor (3) has high boiling point (4) low latent heat of vaporization Correct Answer – (1) has high specific heat 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. Q.6) When a body falls from an aeroplane, there is increase in its – (1) Kinetic energy (2) Mass (3) Acceleration (4) Potential energy Correct Answer – (3) Acceleration 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. For More eBook Visit: www.Rekibafredi.com 5