geomorphology & earth landforms section 6 MCQ Questions & Answers Detailed Explanation

Answer: (a)

In physical geography, the tundra is a biome where tree growth is hindered by low temperatures and short growing seasons.

There are three types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra where the subsoil is permafrost or permanently frozen soil.

Rainfall and snowfall are generally slight due to the low vapour pressure of water in the chilly atmosphere, but as a rule potential evapotranspiration is extremely low, allowing soggy terrain of swamps and bogs even in places that get precipitation typical of deserts of lower and middle latitudes.

Answer: (a)

As per the description of the Continental Drift Theory of Wegner, North & South America Continents drifted toward the west due to Tidal force.

Due to the resistance and friction of Sima, the Western coast of the above two continents folded, causing the formation of the Andes & Rockies mountains.

Answer: (c)

When molten materials of Earth’s interior (magma) do not reach Earth’s surface, they cool and solidify below the surface-are called intrusive igneous rocks.

e.g., granite, diorite, gabbro called Plutonic rocks have larger crystals, compact, resistant and glassy in appearance e.g., quartz, batholith. The rate of cooling is slower been formed at great depths.

1. Sills Some of the lava may push its way through passages in the form of sills or dykes. When magma is being forced upwards, some of the lava may push its way in between two layers of rock and get solidified there. The intrusive rock formed - called sill - almost horizontal.
2. Dykes Magma also forces its way before reaching the main fissure, trying to go up but gets solidified before reaching the surface. These intrusive rocks lying in a slanting direction as an offshoot are called dykes.

Answer: (d)

Answer: (b)

Answer: (a)

It should be mentioned that the plains may be above the or below the sea levels but not higher than the surrounding regions.