09 November Static Quiz 2021 (Geography)

Solution: A Justification: The plates act like a hard and rigid shell compared to Earth’s mantle. This strong outer layer is called the lithosphere. Plate tectonics is the modern version of continental drift, a theory first proposed by scientist Alfred Wegener in 1912. Wegener didn’t have an explanation for how continents could move around the planet, but researchers do now. Plate tectonics is thus said to be the unifying theory of geology. The driving force behind plate tectonics is convection in the mantle. Hot material near the Earth’s core rises, and colder mantle rock sinks. In terms of analogy, it is kind of a pot boiling on a stove. The convection drive plates tectonics through a combination of pushing and spreading apart at mid-ocean ridges and pulling and sinking downward at subduction zones.

Solution: C
Justification: Plates are divided between major and minor plates based on their geographical coverage. The Indian plate is thus a major plate. So, (a) is correct. The subduction zone along the Himalayas forms the northern plate boundary in the form of continent convergence. So, (b) is correct. The peninsular plate is an integral part of the Indian plate. So, (c) is incorrect. In the east, it extends through the Rakinyoma Mountains of Myanmar towards the island arc along the Java Trench. The Western margin follows the Kirthar Mountain of Pakistan. So, (d) is correct

Solution: B
Justification: The lithosphere is broken into a number of plates known as the Lithospheric plates. The molten magma inside the earth moves in a circular manner. These plates move because of the movement of the molten magma inside the earth. Lateral movements between lithospheric plates create transform faults at the sites of plate slippage.

Solution: C
Justification: Iron makes up 5 percent of Earth’s crust and is second in abundance to aluminum among the metals and fourth in abundance behind oxygen, silicon, and aluminum among the elements. Iron, which is the chief constituent of Earth’s core, is the most abundant element in Earth as a whole (about 35 percent) and is relatively plentiful in the Sun and other stars. In the crust the free metal is rare, occurring as terrestrial iron

Solution: B
Justification: The most common chemical elements in the crust are oxygen (46.6%), silicon (27.7), aluminum (8.1), iron (5.0), calcium (3.6), potassium (2.8), sodium (2.6), and magnesium (2.1). Typical mantle rocks have higher magnesium to iron ratio and a smaller proportion of silicon and aluminum than the crust. The solid, inner core of the earth is iron and has a radius of about 760 miles. It is surrounded by a liquid, outer core composed of a nickel-iron alloy.