1. As we move from the equator towards the poles, the value of g decreases (B). This is due to the centrifugal force caused by Earth's rotation, which is greatest at the equator and decreases towards the poles. Additionally, the shape of the Earth is not a perfect sphere; it's slightly flattened at theRead more

    As we move from the equator towards the poles, the value of g decreases (B). This is due to the centrifugal force caused by Earth’s rotation, which is greatest at the equator and decreases towards the poles. Additionally, the shape of the Earth is not a perfect sphere; it’s slightly flattened at the poles and bulging at the equator. This variation in distance from the Earth’s center also affects the gravitational force. As we move towards the poles, we are closer to the Earth’s center, resulting in a stronger gravitational force. However, this increase is offset by the decrease in centrifugal force, leading to a net decrease in the value of g. This decrease is not constant but varies gradually as we move from the equator towards the poles, reaching its maximum value at the poles. Therefore, the correct option is (B) decreases.

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  2. Body weight varies with location on Earth's surface due to differences in gravitational acceleration. It is not the same everywhere on Earth's surface. At the poles (B), gravity is stronger because objects are closer to the Earth's center. At the equator, the centrifugal force caused by Earth's rotaRead more

    Body weight varies with location on Earth’s surface due to differences in gravitational acceleration. It is not the same everywhere on Earth’s surface. At the poles (B), gravity is stronger because objects are closer to the Earth’s center. At the equator, the centrifugal force caused by Earth’s rotation counteracts some of the gravitational force, resulting in slightly lower weight. Therefore, body weight is maximum at the poles and slightly lower at the equator. Additionally, weight can vary with altitude. On hills (D), the distance from the Earth’s center is slightly greater compared to plains, resulting in slightly lower weight. However, this difference is generally negligible unless at extreme altitudes. Thus, body weight is not the same everywhere, being maximum at the poles and slightly lower at the equator.

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  3. An astronaut can jump higher on the lunar surface than on the Earth's surface because the force of gravity on the lunar surface is much less compared to the Earth's surface (C). This weaker gravity allows the astronaut to exert less downward force on the lunar surface, enabling them to achieve greatRead more

    An astronaut can jump higher on the lunar surface than on the Earth’s surface because the force of gravity on the lunar surface is much less compared to the Earth’s surface (C). This weaker gravity allows the astronaut to exert less downward force on the lunar surface, enabling them to achieve greater height in their jump. While the astronaut is not weightless on the Moon (A), there is less gravitational pull due to the Moon’s smaller mass (D), but this difference primarily accounts for the discrepancy in weight, not the ability to jump higher. The absence of atmosphere on the Moon (B) does not significantly affect the astronaut’s ability to jump higher, as it primarily influences air resistance rather than gravitational force. Thus, the correct option is (C) The force of gravity on the lunar surface is very less as compared to the Earth’s surface.

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  4. The work done to hold a weight of 20 kg at a height of 1 m above the ground is zero Joules (D). Work is defined as the product of force and displacement in the direction of the force. When holding an object stationary, like in this scenario, there is no displacement; thus, no work is done against grRead more

    The work done to hold a weight of 20 kg at a height of 1 m above the ground is zero Joules (D). Work is defined as the product of force and displacement in the direction of the force. When holding an object stationary, like in this scenario, there is no displacement; thus, no work is done against gravity. While the weight of the object is 20 kg, and the force due to gravity is approximately 9.81 m/s² (981 N/kg), the vertical displacement is zero since the object is held at a constant height. Therefore, the work done is zero. Options (A), (B), and (C) are incorrect because they imply that work is being done, but in reality, no displacement occurs when holding the weight stationary at a constant height above the ground.

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  5. If a person pushes a wall but fails to displace it, then he does no work (A). In physics, work is defined as the product of force and displacement in the direction of the force. When there is no displacement, regardless of the magnitude of the force applied, the work done is zero. Even though the peRead more

    If a person pushes a wall but fails to displace it, then he does no work (A). In physics, work is defined as the product of force and displacement in the direction of the force. When there is no displacement, regardless of the magnitude of the force applied, the work done is zero. Even though the person exerts force against the wall, if the wall does not move, there is no change in the wall’s position, and hence no work is accomplished. Option (B) is incorrect because negative work implies that energy is being taken away from the system, which doesn’t apply here. Option (C) implies some positive work, but there’s no work done if there’s no displacement. Option (D) is incorrect because maximum work would imply achieving the greatest possible displacement, which isn’t the case if the wall remains stationary. Therefore, the correct option is (A) No work.

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