# Samacheer Kalvi Class 7 Geography Chapter 1 Interior of the Earth Solutions

## Samacheer Kalvi Class 7 Geography Chapter 1 Interior of the Earth Solutions

Welcome to NCTB Solutions. Here with this post we are going to help 7th class students by providing Solutions for Samacheer Kalvi Class 7 Geography Chapter 1 Interior of the Earth. Here students can easily find all the solved solution for class 7 Social Science, Geography Chapter 1, Interior of the Earth Exercise questions. Also here our expert Geography Teacher’s solved all the questions with easily understandable language with proper guidance so that all the students can understand easily. Here on this post students will get Chapter 1 Interior of the Earth exercise solutions. Here all the solutions are based on Tamil Nadu State Board latest syllabus.

#### Interior of the Earth Chapter 1 Solutions :

(1) Nife is made up of __ .

(a) Nickel and ferrous

(b) Silica and aluminum

(c) Silica and magnesium

(d) Iron and magnesium

Correct Option → (a)

Nife is made up of Nickel and ferrous.

(2) Earthquake and volcanic eruption occur near the edges of __

(a) Mountain

(b) Plains

(c) Plates

(d) Plateaus

Correct Option → (a)

Earthquake and volcanic eruption occur near the edges of Mountain.

(3) The magnitude of an earthquake is measured by __

(a) Seismograph

(b) Richter scale

(c) Ammeter

(d) Rotameter

Correct Option → (b)

The magnitude of an earthquake is measured by Richter scale.

(4) The narrow pipe through which magma flow out is called a __

(a) Vent

(b) Crater

(c) Focus

(d) Caldera

Correct Option → (a)

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

(6) __ belt is known as the “Ring of Fire”.

(a) Circum – Pacific

(b) Mid-Atlantic

(c) Mid – Continental

(d) Antarctic

Correct Option → (a)

Circum – Pacific belt is known as the “Ring of Fire”

(II) Fill in the blanks

(1) The core is separated from the mantle by a boundary called ____.

(2) The earthquake waves are recorded by an instrument known as ____.

(3) Magma rises to the surface and spreads over a vast area is known as ____.

(4) An example for active volcano is ____.

(5) Seismology is the study of ____.

(1) → Weichart – Gutenberg discontinuity

(2) → Seismograph

(3) → Fissure eruption

(4) → An example for active volcano is St. Helens USA

(5) → Earthquake

(III) Circle the odd one

(1) Crust, magma, core, mantle

Answer : Here the odd one is Magma.

(2) Focus, epicenter, vent, seismic waves

Answer : Here the odd one is vent

(3) Uttar Kashi, Chamoli, Koyna, Krakatoa

Answer :Here the odd one is Krakatoa

(4) Lava, caldera, silica, crater

Answer :Here the odd one is Silica

(5) Stromboli, Helens, Hawaii, Fujiyama

Answer :Here the odd one is Fujiyama

(IV) Match the following

(1) Earth quake – Japanese term

(2) Sima – Africa

(3) Pacific Ring of Fire – Sudden movement

(4) Tsunami – Silica and magnesium

(5) Mt) Kenya – World volcanoes

(1) Earth quake → Sudden movement

(2) Sima → Silica and magnesium

(3) Pacific Ring of Fire → World volcanoes

(4) Tsunami → Japanese term

(5) Mt. Kenya → Africa

(V) Consider the following statement and Tick the appropriate answer.

(1) Assertion (A) There structure of the earth may be compared to that of an Apple

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

(a) A and R are correct and A explains R

(b) A and R are correct but A does not explain R

(c) A is incorrect but R is correct

(d) Both A and R are incorrect

The answer is option – (a)

A and R are correct and A explains R.

(2) 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) A and R are correct and A explains R

(b) A and R are correct but A does not explain R

(c) A is incorrect but R is correct

(d) Both A and R are incorrect

Correct option is – (a)

A and R are correct and A explains R

(1) Name the outer most layer of the earth.

Crust is the outer most layer.

(2) What is SIAL?

The upper part of the continental crust is made up of aluminum and silica, so it is called Sial.

(3) Name the movement of the Earth’s lithospheric plates?

Tectonic movements of the earths lithospheric plates.

(4) Give an example of extinct volcano.

Mt. Popa of Myanmar is an example of extinct volcano.

(1) What is mantle?

The lower layer of the crust that is separated from the crust by the Mohorovicic discontinuity line, it is called the mantle.

(2) Write note on the core of the earth?

The core is the innermost layer of the earth. It is also known as barysphere. It is separated from the mantle by the weichert Gutenberg discontinuity line. The density of the core is 13.0 g/cm3.

(3) Define Earthquake.

If a sudden movement inside the earth shakes the earth’s crust, that vibration is known as an earthquake.

(4) What is Seismograph?

An instrument that records the waves of an earthquake is called a seismograph.

(5) What is a volcano?

Volcano is a cone shaped mountain through which magma vapor gas etc., comes out from the depths of the earth crust.

(6) Name the three types of volcanoes based on periodicity of eruption.

Volcano can be divided into three groups based on shape – Shield volcano, Cinder-cone volcano, Composite volcano.

(VIII) Give reason :

(1) No one has been able to take samples from the interior of the earth

The core is the innermost layer of the earths crust. The core of the earth interior is associated with high temperatures and there is a lot of pressure here. No samples could be collected from here for this reason.

(IX) Distinguish between

(1) SIAL and SIMA

Sial and Sima both are the part of the Earth crust.

There are the following differences between Sial and Sima:

(1) Sial is a continental crust whereas Sima is oceanic crust.

(2) Sial constituents of Silica and aluminium thus called Sial whereas Sima constituents of Silica and Magnesium.

(3) Sial is less denser than Sima whereas Sima is more denser than Sial.

(2) Active volcano and dormant volcano

Active volcanoes have frequently erupted but dormant volcano have not erupted regularly but they are known to erupt and show signs of possible eruption in the future.

Examples of active volcanoes are Mt. Etna (Italy), Mt. Stromboli (Italy) and Barren Island (Andaman and Nicobar) is the example of Dormant volcano.

(X) Answer the following in detail

(1) Write about the effects of an earthquake?

There are many hazardous effects of earthquake for example Ground shaking, land and mud slides, soil liquefaction, Avalanche. But some effects like ground displacement, floods from dam and levee failures, fire, Tsunami etc. causing immediate concern to the life and properties of the people.

(2) Describe the classification of volcanoes based on the eruptions.

On the basis of eruption, volcanoes can be classified in 3 types.

(1) Active volcanoes : The volcanoes which have erupted frequently or have erupted in recent times is known as active volcanoes.

(2) Dormant volcanoes : The volcanoes which have not erupt regularly but they are known to erupt and show signs of possible eruption in the future are known as dormant volcanoes.

(3) Extinct volcanoes : The volcanoes which have not erupted at all in history yet they retain the features of a volcano is known as extinct volcanoes.

(3) Name the major zones of volcanic activity and explain any one.

The major zones of volcanic activity are

(1) Circum-Pacific belt

(2) Mid-Continental Belt

(3) Mid-Atlantic belt

(4) Intra-Plate volcanos.

Circum-Pacific Belt : nice belt it is also known as the volcanic zones of the convergent oceanic plate margins which includes the volcanoes of eastern and western coastal areas of Pacific Ocean. This volcanic belt is also called as the fire girdle of the Pacific or the fire ring of the Pacific.

(XI) HOTs

(1) The earth’s interior is very hot. Why?

The earth’s hot interior because of the disintegration and decay of radioactive minerals generates more heat.

(2) Are Volcones Destructive (or) Constructive?

Volcanoes has destructive effects such as fire, land & mud slides, and harmful ashes & dusts come out from the volcanoes. But some constructive effects also have such as plateaus and plains are formed, due to volcanic eruption some nutrients are provided to the surrounding soil.

(3) How does volcanoes make an Island?