Physics MCQs

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A concave lens is a type of lens that has a thinner center than edges, and it is sometimes called a diverging lens because it spreads out light rays that are parallel to its axis. The focal length of a lens is a measure of its ability to focus light, and it is defined as the distance from the lens to the point where the light rays converge. In the case of a concave lens with a power of -5D, the focal length would be equal to 1/5 of a meter, or 20 centimeters.

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A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure.

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The weight of a person becomes zero in a lift. Lift moves down with an acceleration of 9.8 meter per sq. second.

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The weight of a person would be maximum at the poles, due to the higher gravitational force acting upon them in these regions. This occurs because Earth is an oblate spheroid, flattened at its poles and bulging at the equator, resulting in a shorter distance from the Earth’s center at the poles and a consequent higher gravitational pull. At the equator, the force is slightly weaker due to a greater distance from the Earth’s center. Weights at the Tropics of Cancer and Capricorn lie in-between the poles and equator, but are closer to the equator’s value.

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Edwin Howard Armstrong was an American electrical engineer who developed FM radio and the superheterodyne receiver system. Edwin Howard Armstrong is the “father of FM radio” and was born in 1890.

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“Fermi” is the unit of length. The femtometre is an SI unit of length equal to 10⁻¹⁵ metres, which means a quadrillionth of one.

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The phenomenon of light rays bending around the corners of obstacles is called diffraction. Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.

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Modern engines also have, additionally, dynamic brake system which works on the principle of converting kinetic energy of the moving train to electricity making the electric motors to work as generators.

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Kinetic Energy is a product of half the Mass times Velocity Squared. When the velocity is doubled, the Kinetic energy would go up four times. If velocity is tripled, kinetic energy would go up nine times. If velocity is increased by 1.5 times the Kinetic energy would go up by 1.5×1.5=2.25 times.

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James Clerk Maxwell made the efforts for the unification of electricity, magnetism and optics field of Physics. He showed that light is an electromagnetic wave. James Clerk Maxwell was a Scottish mathematician, physicist and is known best for his mathematical work on electromagnetism and on the behaviour of gases.