Earths Structure ICSE 9 MCQ

 Earths Structure ICSE 9 MCQ

This set of multiple choice questions covers key concepts from the ICSE Class 9 chapter on Earth’s Structure. It includes topics like layers of the Earth, seismic waves, lithosphere, mantle, core composition, and tectonic activity. Ideal for quick revision, self-assessment, and strengthening foundational geography understanding.

1. Which part of Earth do we sometimes see during volcanic eruptions?
   a) Crust
   b) Mantle
   c) Core
   d) Interior

2. What provides evidence that Earth’s crust is in motion?
   a) Volcanoes
   b) Mountains
   c) Earthquakes
   d) Clouds

3. Which wave type helps us study Earth’s interior?
   a) Light waves
   b) Seismic waves
   c) Sound waves
   d) Ocean waves

4. What causes the refraction of seismic waves inside the Earth?
   a) Magnetic fields
   b) Rotation of Earth
   c) Change in density of materials
   d) Atmospheric pressure

5. Which layer lies directly below the crust?
   a) Core
   b) Asthenosphere
   c) Mantle
   d) Inner core

6. What is the outermost solid layer of the Earth?
   a) Crust
   b) Core
   c) Mantle
   d) Lithosphere

7. Which part of the mantle has a plastic-like flow?
   a) Lithosphere
   b) Crust
   c) Inner core
   d) Asthenosphere

8. The lithosphere is made up of the crust and:
   a) Inner core
   b) Mantle’s top portion
   c) Outer core
   d) Asthenosphere

9. What is the average thickness of the lithosphere?
   a) 10 km
   b) 50 km
   c) 100 km
   d) 500 km

10. What drives the movement of tectonic plates?
    a) Solar heat
    b) Gravity
    c) Thermal energy from mantle
    d) Ocean currents

11. The Earth’s core is mostly made of:
    a) Silica and Magnesium
    b) Nickel and Iron
    c) Aluminium and Iron
    d) Basalt and Granite

12. Why is the Earth’s core called “Nife”?
    a) It contains nitrogen and iron
    b) It is made of nickel and iron
    c) It was discovered by Nife
    d) It is a fiery layer

13. The outer core is in what state?
    a) Solid
    b) Liquid
    c) Gaseous
    d) Plastic

14. The inner core is solid due to:
    a) Low temperature
    b) Lack of iron
    c) Low pressure
    d) High pressure

15. What is the average diameter of Earth’s core?
    a) 1000 km
    b) 7000 km
    c) 5000 km
    d) 2000 km

16. What percent of Earth’s volume is occupied by the mantle?
    a) 10%
    b) 25%
    c) 50%
    d) 83%

17. The crust made of silicon and aluminium is called:
    a) Sima
    b) Core
    c) Sial
    d) Litho

18. The denser part of the crust is:
    a) Lithosphere
    b) Core
    c) Sial
    d) Sima

19. The density of Sima is about:
    a) 2.5 g/cm³
    b) 2.7 g/cm³
    c) 3.0–3.4 g/cm³
    d) 4.5 g/cm³

20. What is the crust’s thickness under oceans?
    a) 70 km
    b) 5–10 km
    c) 20–30 km
    d) 100 km

21. What type of rock is dominant in oceanic crust?
    a) Granite
    b) Basalt
    c) Sandstone
    d) Gneiss

22. Continental crust is mainly composed of:
    a) Basalt
    b) Marble
    c) Granite
    d) Iron

23. The major element in both Sial and Sima is:
    a) Aluminium
    b) Silicon
    c) Iron
    d) Copper

24. What is the approximate density of continental crust?
    a) 2.3 g/cm³
    b) 2.7 g/cm³
    c) 3.4 g/cm³
    d) 4.0 g/cm³

25. Which layer of the mantle is called the asthenosphere?
    a) Lower crust
    b) Top mantle
    c) Inner core
    d) Lithosphere

26. What enables tectonic plates to move?
    a) Magnetic force
    b) Water currents
    c) Flow of asthenosphere
    d) Earth’s spin

27. What are tectonic plates made of?
    a) Only crust
    b) Crust and upper mantle
    c) Only mantle
    d) Core

28. Which of the following is a tectonic plate?
    a) Mediterranean Plate
    b) Tibetan Plate
    c) Indian Plate
    d) Sahara Plate

29. Most earthquakes occur at:
    a) Ocean basins
    b) Plate boundaries
    c) Deserts
    d) Equator