Inside Our Earth Class 7 MCQs | CBSE Geography
Inside Our Earth Class 7 MCQs | CBSE Geography
Class: 7 |
Subject: Social Science |
Section: Geography – Our Environment |
Topic: Inside Our Earth
These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 7 Social Science Examination preparation.
1. What is the innermost layer of the Earth called?
Answer: C. Core
The core is the deepest and hottest layer of the Earth. It is mainly made up of iron and nickel. Temperatures here can reach above 5000°C. It is divided into the outer core (liquid) and inner core (solid).
The core is the deepest and hottest layer of the Earth. It is mainly made up of iron and nickel. Temperatures here can reach above 5000°C. It is divided into the outer core (liquid) and inner core (solid).
2. Which layer of the Earth do we live on?
Answer: C. Crust
The crust is the outermost and thinnest layer of the Earth. It is where all living organisms exist, and where landforms like mountains, plains, and oceans are found.
The crust is the outermost and thinnest layer of the Earth. It is where all living organisms exist, and where landforms like mountains, plains, and oceans are found.
3. The mantle lies between which two layers?
Answer: A. Crust and Core
The mantle is the middle layer of the Earth. It lies just below the crust and above the core. It is very thick and composed of semi‑molten rocks called magma.
The mantle is the middle layer of the Earth. It lies just below the crust and above the core. It is very thick and composed of semi‑molten rocks called magma.
4. What is the thickness of the Earth’s crust on continents?
Answer: B. About 35 km
Continental crust is thicker than oceanic crust. It averages about 35 km but may extend up to 70 km under major mountain ranges.
Continental crust is thicker than oceanic crust. It averages about 35 km but may extend up to 70 km under major mountain ranges.
5. The Earth’s radius is approximately:
Answer: A. 6400 km
The Earth’s radius is about 6400 km. This measurement helps scientists understand the depth and structure of Earth’s internal layers.
The Earth’s radius is about 6400 km. This measurement helps scientists understand the depth and structure of Earth’s internal layers.
6. Which layer is known as the ‘sima’ layer?
Answer: B. Oceanic crust
Sima is made of silica and magnesium and forms the oceanic crust. It is denser than the continental crust (sial).
Sima is made of silica and magnesium and forms the oceanic crust. It is denser than the continental crust (sial).
7. The continental mass is made up of:
Answer: C. Sial
Sial consists of silica and aluminium. It forms the upper layer of continental crust and is lighter than sima.
Sial consists of silica and aluminium. It forms the upper layer of continental crust and is lighter than sima.
8. Which part of the core is liquid?
Answer: B. Outer core
The outer core is in liquid state due to extremely high temperature. Movement of molten metals here generates Earth’s magnetic field.
The outer core is in liquid state due to extremely high temperature. Movement of molten metals here generates Earth’s magnetic field.
9. What is magma?
Answer: B. Molten rock beneath Earth’s surface
Magma is semi‑molten rock found in the mantle. When it erupts onto the surface, it is called lava.
Magma is semi‑molten rock found in the mantle. When it erupts onto the surface, it is called lava.
10. Which layer is the thickest?
Answer: B. Mantle
The mantle is about 2900 km thick, making it the thickest layer. It makes up the largest volume of Earth.
The mantle is about 2900 km thick, making it the thickest layer. It makes up the largest volume of Earth.
11. The lithosphere includes:
Answer: C. Crust + upper mantle
Lithosphere is the rigid outer layer made of crust and uppermost mantle. It is broken into tectonic plates.
Lithosphere is the rigid outer layer made of crust and uppermost mantle. It is broken into tectonic plates.
12. Which instrument records earthquake waves?
Answer: C. Seismograph
A seismograph records seismic waves generated by earthquakes. Scientists study these waves to understand Earth’s interior.
A seismograph records seismic waves generated by earthquakes. Scientists study these waves to understand Earth’s interior.
13. What are the main minerals in the core?
Answer: B. Iron and nickel
Because of iron (Fe) and nickel (Ni), the core is often called ‘Nife’. These metals make it very dense.
Because of iron (Fe) and nickel (Ni), the core is often called ‘Nife’. These metals make it very dense.
14. Which crust is thinner?
Answer: B. Oceanic crust
Oceanic crust is only about 5–10 km thick, much thinner than continental crust.
Oceanic crust is only about 5–10 km thick, much thinner than continental crust.
15. Lava is:
Answer: B. Molten rock on Earth’s surface
When magma erupts through volcanoes and reaches the surface, it is called lava.
When magma erupts through volcanoes and reaches the surface, it is called lava.
16. The inner core is:
Answer: C. Solid
Despite very high temperature, immense pressure keeps the inner core in solid state.
Despite very high temperature, immense pressure keeps the inner core in solid state.
17. The study of Earth’s interior is mainly done through:
Answer: C. Seismic waves
Since humans cannot go deep inside Earth, scientists study seismic waves produced by earthquakes to understand internal structure.
Since humans cannot go deep inside Earth, scientists study seismic waves produced by earthquakes to understand internal structure.
18. Which layer generates Earth’s magnetic field?
Answer: C. Outer core
Movement of molten iron and nickel in the liquid outer core produces Earth’s magnetic field.
Movement of molten iron and nickel in the liquid outer core produces Earth’s magnetic field.
19. Which is the hottest layer?
Answer: C. Core
The core has extremely high temperatures due to pressure and radioactive heat.
The core has extremely high temperatures due to pressure and radioactive heat.
20. The Earth is made up of how many major layers?
Answer: B. Three
The Earth has three main layers — Crust, Mantle, and Core — each with distinct composition, thickness, and properties.
The Earth has three main layers — Crust, Mantle, and Core — each with distinct composition, thickness, and properties.