Tag: geography

Quizzes (501) Questions (6412)

Questions Related to geography

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

The Mohorovicic Discontinuity marks the _____ limit of Earth's crust.

  1. lower

  2. upper

  3. middle

  4. side
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Mohorovicic Discontinuity marks the lower limit of Earth's crust. It occurs at an average depth of about 8 kilometers beneath the ocean basins and 32 kilometers beneath continental surfaces. Mohorovicic was able to use his discovery to study thickness variations of the crust. He discovered that the oceanic crust has a relatively uniform thickness, while continental crust is thickest under mountain ranges and thinner under plains.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

Third layer of Earth which comes after Mantle of Earth is known as __________________.

  1. The Inner Core

  2. The Crust

  3. The Outer Core

  4. The Mantle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Earth mainly consists of four layers namely crust, mantle, outer core and inner core:

Crust: This is about 8 km thick inside and is highly explored. The continental crust is composed mostly of granite. The oceanic crust consists of a volcanic lava rock called basalt.

Mantle: It is the largest layer of the Earth which is 1800 miles thick. It is composed mostly of silicate rocks rich in magnesium and iron.

Outer core: It is located beneath the mantle. The outer core is composed of melted metals like nickel and iron.

Inner core: It is composed of an iron-nickel alloy and some light elements.

Layer that lies immediately after the mantle is the outer core.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

In geology the word __________  is used for a surface at which seismic waves change velocity.

  1. continuity

  2. discontinuity

  3. mental

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In geology the word "discontinuity" is used for a surface at which seismic waves change velocity. One of these surfaces exists at an average depth of 8 kilometers beneath the ocean basin and at an average depth of about 32 kilometers beneath the continents. At this discontinuity, seismic waves accelerate. This surface is known as the Mohorovicic Discontinuity or often simply referred to as the "Moho."

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

Which of the following statement is false?

  1. the P-wave shadow zone is larger than the S-wave shadow zone.

  2. P waves travel more slowly in the outer core than in the lower mantle

  3. Liquids do not transmit S waves

  4. Seismic waves follow curved paths through the interior of the Earth
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All seismic waves do not cause earth quake. Certain magnitude is necessary to cause an earthquake.

Region on earth’s surface where earth quake can be barely detected after an occurrence of a seismic wave is called shadow region.

In the given options all are correct but the statement ‘P-wave shadow zone is larger than the S-wave shadow zone’ is false and vice versa is true.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

The physical evidence that the core is composed mostly of iron is ________________.

  1. the known mass of Earth requires material of high density at the core.

  2. volcanoes erupt material from the core to the surface.

  3. scientists have sampled the core and determined its composition.

  4. all of these.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Outer core: It is located beneath mantle. The outer core is composed of the melted metals like nickel and iron.

Inner core: It is composed of an iron–nickel alloy and some light elements.

Thus core is mostly constituted by iron. This fact can be known by the measurement of densities of various layers of earth. At the core there is a higher density and this density could only be possible by higher amounts of iron present in the core.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

When sesimic waves pass across the boundary between two different materials, ___________ .

  1. the waves change in velocity

  2. the waves refract

  3. the waves reflect

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Seismic wave is a wave of energy caused due to sudden break or explosion of a rock in the earth’s interior.

When seismic wave passes from one material to the other material it either reflects, refracts or changes it velocity.

This phenomenon of seismic reflection or refraction enables geologists to study the interior of earth because reflection and refraction differs with the type of material.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

What drives plate tectonics?

  1. Thermal convection

  2. Solar energy

  3. thermal conduction

  4. Erosion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tectonic plates are those that are present beneath the earth surface and have been moving throughout the earth’s history.

What drives tectonic plates is not known clearly but one theory is that the convection drives heated up plates to move towards the surface and after they reach the ceiling they are deflected sideways. 

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

Where is the Earth's magnetic field generated?

  1. In the outer core

  2. In the inner core

  3. In the crust

  4. In the mantle
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Earth’s magnetic field exerts from earth’s interior to the outer surface.

Inner core is mostly made of iron and temperature is about 5,700°C, at this temperature iron is as hot as surface of sun, but crushing pressure caused by gravity prevents it from becoming liquid and hence cannot produce magnetic field.

But the outer core has a 2,000 km thick layer of iron, nickel, and small quantities of other metals. As the pressure is lower in outer core when compared to the inner core metals exists in fluid state. 

Differences in temperature, pressure and composition within the outer core cause convection currents in the molten metal and earths spin result in whirling movements of the liquid metal resulting in generation of electric currents and there by producing magnetic field.

Multiple choice components of earth geography inside our earth the earth's structure structure of the earth our world earth and structure

The boundary between the mantle and the core lies at a depth of approximately ________ .

  1. 3000 kilometers

  2. 300 kilometers

  3. 1000 kilometres

  4. 5000 kilometers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Earth mainly consists of four layers namely crust, mantle, outer core and inner core.

The boundary between the mantle and the core lies at a depth of approximately 2891 km or 3000km.

The core–mantle boundary of the Earth lies between the planet's silicate mantle and its liquid iron-nickel outer core