Q33 · UPSC Prelims 2025 · Set A · Environment and Ecology

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Consider the following statements:Statement I: Scientific studies suggest that a shift is taking place in the Earth's rotation and axis.Statement II: Solar flares and associated coronal mass ejections bombarded the Earth's outermost atmosphere with tremendous amount of energy.Statement III: As the Earth's polar ice melts, the water tends to move towards the equator.Which one of the following is correct in respect of the above statements?

A Both Statements II and III are correct and both of them explain Statement I
B Both Statement II and Statement III are correct but only one of them explains Statement I
C Only one of the Statement II and III is correct and that explains Statement I
D Neither Statement II nor Statement III is correct

Correct answer: (b) Both Statement II and Statement III are correct but only one of them explains Statement I

Explanation

  1. A

    Both Statements II and III are correct and both of them explain Statement I

    Both II and III correct and both explain I. Solar flares and CMEs dump energy into the thermosphere and ionosphere. They do not shift the rotation axis the way ice melt does. II is true as space weather; it does not explain I.

  2. B

    Both Statement II and Statement III are correct but only one of them explains Statement I

    Both II and III are correct but only one of them explains I. III is the explanation: meltwater from polar ice moves toward the equator, redistributes mass, and studies report a tiny polar-motion / length-of-day signal. II is correct space physics, not the cause of I.

  3. C

    Only one of the Statement II and III is correct and that explains Statement I

    Only one of II and III is correct. Both statements hold; only the explanation link is one-way.

  4. D

    Neither Statement II nor Statement III is correct

    Neither. Ice-mass shift is the standard geophysics line for I.

Summary. Official key is (b): solar flares (II) and meltwater moving toward the equator (III) are both real, but only ice-mass shift explains a measurable change in Earth’s rotation and axis. Flares light up the outer atmosphere; they do not re-aim the pole. (a) treats both as explanations; (c) drops a true statement; (d) drops both.

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