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GeographyMediumAsked in: UPSC Civil Services · CSE Prelims 2022, GS Paper I

If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth? 1. GPS and navigation systems could fail. 2. Tsunamis could occur at equatorial regions. 3. Power grids could be damaged. 4. Intense auroras could occur over much of the Earth. 5. Forest fires could take place over much of the planet. 6. Orbits of the satellites could be disturbed. 7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted. Select the correct answer using the code given below:

  1. A.1, 2, 4 and 5 only
  2. B.2, 3, 5, 6 and 7 only
  3. C.1, 3, 4, 6 and 7 only
  4. D.1, 2, 3, 4, 5, 6 and 7

Correct answer

C. 1, 3, 4, 6 and 7 only

Explanation

The correct answer is C, 1, 3, 4, 6 and 7 only. A strong solar storm disturbs the Earth's magnetic field and upper atmosphere, which hits electrical and radio systems, but it cannot cause tsunamis or forest fires.

Solar flares and coronal mass ejections send bursts of radiation and charged particles towards the Earth. These set off geomagnetic storms. Errors creep into GPS signals that pass through the disturbed ionosphere, and induced currents can overload transformers, as in the 1989 Quebec blackout. The upper atmosphere heats and swells, increasing drag on low-orbit satellites and changing their orbits. Shortwave radio over the poles fades, so flights are rerouted, and auroras are seen far beyond the polar regions.

Statements 2 and 5 are wrong: tsunamis come from undersea earthquakes and landslides, and solar particles do not reach the ground with enough energy to start fires.

So A, B and D are wrong because each includes the false statements 2 and 5.

Exam tip: solar storm hits the sky and wires (GPS, grids, satellites, HF radio, auroras), not the sea or forests.

Practice Questions

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Q3.GeographyAsked in: CDS · CDS-II 2026, GKMedium

Consider the following statements with reference to earthquakes:

1. Collapse earthquakes are most common.

2. Tsunamis are waves generated by the tremors and not an earthquake in itself.

3. High magnitude earthquakes i.e. 8+ are quite rare whereas 'tiny' types occur almost every minute.

Which of the statements given above are correct?

  1. A.1 and 2 only
  2. B.1 and 3 only
  3. C.2 and 3 only
  4. D.1, 2 and 3
Show answer
Correct answer: C. 2 and 3 only

Statement 1 is false because tectonic earthquakes, not collapse earthquakes, are the most common type. Earthquakes are grouped by cause: tectonic (sliding of rocks along a fault), volcanic, collapse (the roofs of underground mines or caverns falling in), explosion (from nuclear or chemical blasts) and reservoir-induced.

Q4.GeographyAsked in: CDS · CDS-II 2016, GKMedium

With reference to earthquakes, which of the following statements are correct?

1. Earthquakes largely occur along the converging plate boundaries.

2. Point of origin of earthquake in lithosphere is known as focus/hypocentre.

3. Intensity of earthquake decreases with distance from the epicentre.

4. Epicentre of earthquake always remains over continents only.

Select the correct answer using the code given below.

  1. A.1 and 2 only
  2. B.1, 2 and 3
  3. C.2 and 3 only
  4. D.1 and 4
Show answer
Correct answer: B. 1, 2 and 3

The first three statements are true, while statement 4 is false because many earthquakes have their epicentre under the sea.