Imp Questions For All Chapters – Geography Class 9th
Short Questions
1. What causes earthquakes?
Answer: Movements in the earth’s interior release energy, causing the ground to shake.
2. What is the Richter scale used for?
Answer: It measures the magnitude (strength) of an earthquake.
3. Where was the epicenter of the Nepal earthquake in 2015?
Answer: Lamjung, Nepal.
4. What is the focus of an earthquake?
Answer: The point inside the earth where the earthquake starts.
5. Name one fold mountain.
Answer: The Himalayas.
6. What forms a block mountain?
Answer: Tension pulls rocks apart, lifting a block between faults.
7. What is a rift valley?
Answer: A deep valley formed when land sinks between two faults.
8. Name a fissure-type volcano example.
Answer: Deccan Plateau, India.
9. What is lava?
Answer: Molten magma that reaches the earth’s surface.
10. What are slow movements?
Answer: Movements that happen over a long time, like forming mountains.
11. What are sudden movements?
Answer: Quick events like earthquakes and volcanoes.
12. What does compression do to rocks?
Answer: It pushes rocks together, forming folds.
13. What does tension do to rocks?
Answer: It pulls rocks apart, forming faults.
14. Name an active volcano.
Answer: Mt. Fujiyama, Japan.
15. What is a dormant volcano?
Answer: A volcano that hasn’t erupted for a long time but might.
16. What are P waves?
Answer: Fast seismic waves that move back and forth.
17. What are S waves?
Answer: Slower seismic waves that move up and down.
18. What are L waves?
Answer: Surface waves that cause the most damage.
19. What is a seismogram?
Answer: A tool that records earthquake waves.
20. What can earthquakes cause in oceans?
Answer: Tsunamis.
Long Questions
1. Why did the Nepal earthquake in 2015 cause so many deaths?
Answer: The Nepal earthquake in 2015 was a strong 7.9 magnitude, causing buildings to collapse and killing nearly 1500 people. It struck near Kathmandu, a crowded city, making the damage worse with its epicenter at Lamjung. Aftershocks, like the 6.6 magnitude one, kept hitting, leading to more deaths.
2. How do fold mountains like the Himalayas form?
Answer: Fold mountains like the Himalayas form when energy waves slowly push soft rocks together, folding them over millions of years. This pressure lifts the earth’s crust into high peaks and ridges through a process called mountain-building. The chapter explains this is how the Himalayas were created.
3. What is the difference between block mountains and rift valleys?
Answer: Block mountains, like the Meghalaya Plateau, form when tension lifts a flat block of land between two faults. Rift valleys, like the Narmada Valley, form when tension makes land sink between faults, creating a deep valley. The chapter shows both happen due to pulling forces but in opposite ways.
4. Why are most volcanoes found near plate boundaries?
Answer: Most volcanoes are near plate boundaries where the earth’s crust splits into moving plates that meet or pull apart. These edges let magma escape from below, forming volcanoes as it erupts over time. The chapter’s map (Fig. 2.18) shows them lining up along these boundaries.
5. How do earthquakes affect people and the land?
Answer: Earthquakes shake the ground, making buildings collapse and causing deaths and property loss. They crack land, trigger landslides, or start tsunamis, changing the earth’s surface. The chapter says they also disrupt roads and communication, affecting people’s lives.
6. What happens during a volcanic eruption?
Answer: During a volcanic eruption, hot magma, ash, and gases burst from the earth’s mantle to the surface. It can form cone-shaped mountains or flat plateaus, depending on how magma comes out. The chapter notes it may destroy areas but can also create new land.
7. How do P, S, and L waves differ in an earthquake?
Answer: P waves are fast, moving back and forth through all materials, shaking things side to side. S waves are slower, moving up and down only through solids, causing more harm. L waves travel along the surface, slowest but most destructive, says the chapter.
8. Why are some volcanoes called active, dormant, or extinct?
Answer: Active volcanoes, like Mt. Fujiyama, erupt often because they’re still working now. Dormant ones, like Mt. Vesuvius, haven’t erupted lately but could, while extinct ones, like Mt. Kilimanjaro, stopped long ago. The chapter classifies them by how often they erupt.
9. How does the earth’s crust move to create continents?
Answer: The earth’s crust moves slowly up or down due to energy from the mantle, lifting land to form continents. This continent-building process can also make plateaus or sink land into sea-beds over millions of years. The chapter explains it shapes the earth’s big landmasses.
10. What can we learn from a seismogram during an earthquake?
Answer: A seismogram records earthquake waves, showing the quake’s strength on the Richter scale. It tracks P, S, and L waves to tell us when and how hard they hit, as seen in Fig. 2.11. The chapter says modern ones detect tiny shakes for better safety.
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