geomorphology & earth landforms section 9 MCQ Questions & Answers Detailed Explanation

Answer: (a)

The Black Forest is an example of a block mountain. The Black Forest is a wooded mountain range in Baden-Wurttemberg, southwestern Germany. It is bordered by the Rhine valley to the west and south.

The highest peak is the Feldberg with an elevation of 1,493 metres (4,898 ft). The region is almost rectangular with a length of 160 km (99 mi) and a breadth of up to 60 km (37 mi).

Answer: (d)

As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and Earth, and the Moon fully or partially blocks the Sun.

This can happen only at the new moon when the Sun and the Moon are in conjunction as seen from Earth. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses only part of the Sun is obscured.

Answer: (a)

Due to gravity, our Earth has an atmosphere. Gravity causes the gases to be held close to the earth instead of escaping into outer space. Besides, gravity makes the atmosphere denser closer to the Earth – the upper layers push down against the lower layers.

Answer: (b)

Alluvial fans are fan-shaped deposits of water transported material (alluvium). They typically form at the base of topographic features where there is a marked break in slope.

Consequently, alluvial fans tend to be coarse-grained, especially in their mouths. At their edges, however, they can be relatively fine-grained.

Answer: (d)

The Core is made up of heavier rocks having a density of 3 g/cm³. This type of rock found in the oceanic crust is basalt.

The mean density of material in the oceanic crust is 2.7 g/cm³.

The Mantle has a density higher than the crust’s (3.4 g/cm³).

The crust and the uppermost part of the mantle are called the lithosphere. Its thickness ranges from 10-200 km. The lower mantle extends beyond the asthenosphere. It is in a solid state.

The density of material at the mantle core boundary is around 5 g/cm³ and at the centre of the earth at 6,300 km, the density value is around 13g/cm³.

The core is made up of very heavy material mostly constituted by nickel and iron. It is sometimes referred to as the nife layer.

Answer: (d)