Physics MCQs

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Stress is the force acting per unit area. It is the internal force reaction per unit area developed as a result of external force.

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The latent heat Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. It causes change in state or phase but not in temperature.

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Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The capillary action is among the following works while we wipe with a towel.

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The north pole of a magnet in a compass points north because it is attracted to the Earth’s magnetic south pole, which is located near Earth’s geographic north pole. The geographic north pole of earth corresponds to magnetic south pole and geographic south pole of earth corresponds to magnetic north pole. The direction in which a compass needle points is known as magnetic north. This is not exactly the direction of the North Magnetic Pole. Instead, the compass aligns itself to the local geomagnetic field, which varies in a complex manner over the Earth’s surface. The angular difference between magnetic north and true north (defined in reference to the Geographic North Pole), at any particular location on the Earth’s surface, is called the magnetic declination. Most map coordinate systems are based on true north, and magnetic declination is often shown on map legends so that the direction of true north can be determined from north as indicated by a compass.

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The largest practical unit of mass is called as Chandra Shekhar Limit (C.S.L) which is equivalent to 1.4 times the mass of Sun. Chandrasekhar limit is the maximum mass theoretically possible for a stable white dwarf star. This limiting value was named after Indian-born astrophysicist Subrahmanyan Chandrasekhar, who formulated it in 1930. Using Albert Einstein’s special theory of relativity and the principles of quantum physics, Chandrasekhar showed that it is impossible for a white dwarf star, which is supported solely by a degenerate gas of electrons, to be stable if its mass is greater than 1.44 times the mass of the Sun.

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The slope of a straight line joining two points on a velocity-time graph gives the average acceleration between these two points. Depending on the sign of slope, the average acceleration can be positive or negative.

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The velocity of rocket at any time is directly proportional to the exhaust speed of the gases and to the natural log of ratio of intial mass of rocket to its mass at that instant. V = u log(m1/m2)

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The angle of friction is indeed equal to the angle of repose. The angle of repose is, to put it simply, the steepest angle at which a sloping surface formed of a particular loose material is stable. It signifies the maximum angle at which an object can rest on an inclined plane without sliding.

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Electron volt is a practical unit of energy. Some practical units of energy are: 1 erg = 10^-7 J 1 calorie = 4.2 J 1 Kilowatt hour = 3.6 x 10⁶ J 1 Electron volt(ev) = 1.6 x 10^-19 J

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At sea level, the difference between the value of acceleration due to gravity at the poles and at the equator is 1.80 cm s^-2. The value of acceleration due to gravity increases as we go from equator to the poles.