Answer: A

Explanation:

• Seismic belt, narrow geographic zone on the Earth’s surface along which most earthquake activity occurs. The two major seismic belts are the Circum-Pacific Belt, which surrounds the Pacific Ocean, and the Alpine Belt or Alpine-Himalayan orogenic belt, which stretches from the Azores through the Mediterranean and Middle East to the Himalayas and Indonesia, where it joins the Circum-Pacific Belt. A purely oceanic seismic belt lies along the mid-Atlantic ridge.


• Seismicity of West and Central Africa is low to moderate, as is normal with stable continental. Hence, option (a) is correct.

Answer: B

Explanation:

Sea floor spreading is verified using these phenomena:

• It was realised that all along the mid-oceanic ridges, volcanic eruptions are common and they bring huge amounts of lava to the surface in this area. The sediments on the ocean floor are unexpectedly very thin.


• The age of the rocks increases as one moves away from the crest.


• The ocean crust rocks are much younger than the continental rocks.


• The sediments on the ocean floor are unexpectedly very thin.


• The deep trenches have deep-seated earthquake occurrences while in the mid-oceanic ridge areas, the quake foci have shallow depths.

Hence, statement 2 is incorrect.

Answer: B

Explanation:

Some initial conditions for the emergence of a tropical cyclone are:

1. Large and continuous supply of warm and moist air that can release enormous latent heat.


2. Strong Coriolis force that can prevent filling of low pressure at the centre (absence of Coriolis force near the equator prohibits the formation of tropical cyclone between 0°-5° latitude).


3. Unstable condition through the troposphere that creates local disturbances around which a cyclone develops.


4. Finally, absence of strong vertical wind wedge, which disturbs the vertical transport of latent heat.

Hence, option (b) is correct.

Answer: A

Explanation:

The plates act like a hard and rigid shell compared to Earth’s mantle. This strong outer layer is called 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 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 drives plate tectonics through a combination of pushing and spreading apart at mid-ocean ridges and pulling and sinking downwards at subduction zones. Hence, statement 2 is correct.

Answer: A

Explanation:

The latitudinal extent of India begins from nearly 8 degrees north. An Indian island cannot begin from zero-degree latitude. The islands of the Arabian sea include Lakshadweep and Minicoy. These are scattered between 8°N-12°N and 71°E -74°E longitude. These islands are located at a distance of 280 km-480 km off the Kerala coast. The entire island group is built of coral deposits. Hence, statement 3 is correct.