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By Savita S. More

TN Board Class 7 Geography Unit 1 Interior of the Earth

If you are looking for TN Board Class 7 Geography Unit 1 Interior of the Earth then you are at the right place. Here we are providing solutions as well as additional QA / Important Notes.

 

Choose the correct answer

Nife is made up of ___________ .

  • Nickel and ferrous
  • Silica and aluminum
  • Silica and magnesium
  • Iron and magnesium

 

Earthquake and volcanic eruption occur near the edges of ______________.

  • Mountain
  • Plains
  • Plates
  • Plateaus

 

The magnitude of an earthquake is measured by ______________.

  • Seismograph
  • Richter scale
  • Ammeter
  • Rotameter

 

The narrow pipe through which magma flow out is called a ______________.

  • Vent
  • Crater
  • Focus
  • Caldera

 

____________ Volcano is known as light house of Mediterranean Sea.

  • Stromboli
  • Krakota
  • Fujiyama
  • Kilimanjaro

 

_________ belt is known as the “Ring of Fire”.

  • Circum – Pacific
  • Mid-Atlantic
  • Mid – Continental
  • Antarctic

 

 

Fill in the blanks-

  1. The core is separated from the mantle by a boundary called ___________.[Weichart-Gutenberg discontinuity.]
  2. The earthquake waves are recorded by an instrument known as __________.[seismograph]
  3. Magma rises to the surface and spreads over a vast area is known as __________.[fissure eruption.]
  4. An example for active volcano is ______________.[Mt. Stromboli]
  5. Seismology is the study of __________.[earthquakes]

 

Circle the odd one

  •  crust, magma, core, mantle
  • focus, epicenter, vent, seismic waves
  • Uttar Kashi, Chamoli, Koyna, Krakatoa
  • lava, caldera, silica, crater
  • Stromboli, Helens, Hawaii, Fujiyama

Answer-

magma (crust, core, and mantle are layers of the Earth, magma is molten rock)

vent (focus, epicenter, and seismic waves are related to earthquakes, vent is related to volcanoes)

Krakatoa (Uttar Kashi, Chamoli, and Koyna are in India, Krakatoa is in Indonesia)

silica (lava, caldera, and crater are volcanic features, silica is a mineral)

Hawaii (Stromboli, Helens, and Fujiyama are individual volcanoes, Hawaii is a location with multiple

 

Match the following

  • Earth quake – Japanese term
  • Sima – Africa
  • Pacific Ring of Fire- Sudden movement
  • Tsunami – Silica and magnesium
  • Mt. Kenya – World volcanoes

Answers

  • Earthquake – Sudden movement
  • Sima – Silica and magnesium
  • Pacific Ring of Fire – World volcanoes
  • Tsunami – Japanese term
  • Mt. Kenya – Africa

 

Consider the following statement and ( )

 

Tick the appropriate answer

Assertion (A): There structure of the earth may be compared to that of anApple.

Reason (R): The interior of the earth consists of crust, mantle and core.

  • A and R are correct and R explains A
  • A and R are correct but R does not explain A
  • A is incorrect but R is correct
  • Both A and R are incorrect

 

Assertion (A): The Pacific Ocean includes two thirds of the world’s volcanoes.

Reason (R): The boundary along the Eastern and Western coast areas of the Pacific Ocean is known as the Pacific Ring of Fire.

  • A and R are correct and R explains A
  • A and R are correct but R does not explain A
  • A is incorrect but R is correct
  • Both A and R are incorrect

 

Answer in a word.

 

Name the outer most layer of the earth.

Crust

 

What is SIAL?

Continental crust

 

Name the movement of the Earth’s lithospheric plates?

Tectonics

 

Give an example of extinct volcano.

Mt. Kilimanjaro

 

 

Answer the following briefly

 

What is mantle?

The mantle is the layer of the Earth located between the crust and the core. It extends to a depth of about 2,900 km and is composed of silicate minerals that are rich in iron and magnesium. The mantle is divided into the upper and lower mantle, with the upper mantle being less dense and the lower mantle being more dense. The mantle is semi-molten, allowing it to flow slowly, which drives the movement of tectonic plates on the Earth’s surface.

 

Write note on the core of the earth?

The core of the Earth is the innermost layer, located beneath the mantle. It is divided into two parts: the outer core and the inner core. The outer core is liquid and composed mainly of iron and nickel, extending from about 2,900 km to 5,150 km beneath the Earth’s surface. The inner core is solid, also primarily composed of iron and nickel, and extends from 5,150 km to 6,371 km at the center of the Earth. The core has very high temperatures and pressures, with the inner core being extremely dense.

 

Define Earthquake.

An earthquake is a sudden shaking or movement of the Earth’s crust caused by the release of stress accumulated along geological faults or by volcanic activity. The point within the Earth where the earthquake originates is called the focus, and the point directly above it on the surface is called the epicenter. Earthquakes release energy in the form of seismic waves, which cause the ground to shake.

 

What is Seismograph?

A seismograph is an instrument used to detect and record the vibrations caused by seismic waves generated by earthquakes or other seismic events. It measures the magnitude and duration of the earthquake by recording the motion of the ground. The data collected by seismographs are crucial for understanding the characteristics and impacts of earthquakes.

 

What is a volcano?

A volcano is an opening or vent in the Earth’s crust through which molten rock (magma), ash, and gases escape from below the surface. When magma reaches the surface, it is called lava. Volcanoes are formed by the accumulation of erupted materials around the vent, creating a conical shape. Volcanic eruptions can vary from gentle flows to explosive events, depending on the properties of the magma and the geological conditions.

 

Name the three types of volcanoes based on periodicity of eruption.

The three types of volcanoes based on periodicity of eruption are:

  • Active volcanoes: Erupt frequently (e.g., Mt. Stromboli, Mauna Loa).
  • Dormant volcanoes: Have not erupted for a long time but may become active again (e.g., Vesuvius, Krakatoa).
  • Extinct volcanoes: Have not erupted in the past 1,000 years and are unlikely to erupt again (e.g., Mt. Kilimanjaro, Mt. Popa).

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