Test Series Prelims 2021

  1. The collision between a continental lithospheric plate and an oceanic lithospheric plate leads to formation of?

a) A Volcanic Island arc

b) A chain of coastal volcanic mountains

c) A mid-oceanic ridge

d) A transform fault

Answer: (b)

Explaination: The collision of a continental plate with an oceanic plate results in the oceanic plate being sub ducted beneath the continental plate. The surface features that are formed include a deep offshore trench and a chain of coastal volcanic mountains.

  • Which amongst the following countries is situated on ‘Pacific Ring of Fire’

a) Brazil

b) Australia

c) Chile

d) India

Answer: (c)

Explaination: The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. Roughly 90% of all earthquakes occur along the Ring of Fire, and the ring is dotted with 75% of all active volcanoes on Earth. 

  • Air moving from the poles toward the equator turns west. The primary cause of this global deflection is?

a) The geoids shape of the earth

b) The tilt of Earth’s axis relative to its Orbital plane

c) The rotation of Earth on its axis

d) The shape and size of land masses

Answer: (c)


Once air has been set in motion by the pressure gradient force, it undergoes an apparent deflection from its path, as seen by an observer on the earth. This apparent deflection is called the “Coriolis force” and is a result of the earth’s rotation. As air moves from high to low pressure in the northern hemisphere, it is deflected to the right by the Coriolis force. In the southern hemisphere, air moving from high to low pressure is deflected to the left by the Coriolis force.

  • Most of the weather phenomena take place in troposphere only because?

a) Temperature remains almost constant in troposphere

b) It contains electrically charged particles

c) It absorbs harmful ultraviolet radiation from the sun

d) It contains almost all the water vapour and most dust particles

Answer: (d)

  • Which one of the following pairs is NOT correctly matched

a) Rio de la Plata:    Brazil

b) Gulf of California:    Mexico

c) Gulf of Aqaba:    Jordan

d) Gulf of Aden:    Yemen

Answer: (a)

Explaination: Río de la Plata, a tapering intrusion of the Atlantic Ocean on the east coast of South America between Uruguay to the north and Argentina to the south. While some geographers regard it as a gulf or as a marginal sea of the Atlantic, and others consider it to be a river, it is usually held to be the estuary of the Paraná and Uruguay rivers (as well as of the Paraguay River, which drains into the Paraná).

The Gulf of California is the body of water located between the Mexican mainland and the Baja California Peninsula. The Gulf of California is also known as the Sea of Cortez, and is considered to be one of the world’s most diverse seas. There are portions of the Gulf of California that have been declared as UNESCO World Heritage Sites.

Created by seismic activity along the Afro-Syrian Rift, the Gulf of Aqaba is a deep narrow body of water, bordered by Israel, Jordan, Egypt and Saudi Arabia and is one of the hinges connecting the Asian and African continents. 

Gulf of Aden, deepwater basin that forms a natural sea link between the Red Sea and the Arabian Sea, Named for the seaport of Aden, in southern Yemen, the gulf is situated between the coasts of Arabia and the Horn of Africa. 

  • Which of the following pair of warm ocean currents move away from Equator?

a) Alaska and Humboldt

b) Antilles and Brazilian

c) East Australian and Oyashio

d) Agulhas and Labrador

Answer: (b)

Explaination: The Antilles Current is a highly variable surface ocean current of warm water that flows north-easterly past the island chain that separates the Caribbean Sea and the Atlantic Ocean. The current results from the flow of the Atlantic North Equatorial Current, The Brazil Current is a warm water current that flows south along the Brazilian south coast to the mouth of the Río de la Plata. This current is caused by diversion of a portion of the Atlantic South Equatorial Current from where that current meets the South American continent.

  • Which of the following is NOT correct regarding shifting cultivation form of agriculture?

(a) It occurs mainly in tropical environments.

(b) Farmers clear land using a slash and burn technique

(c)  Cultivation of cash crops meant for exports

(d) It was practiced sustainably by indigenous peoples but now is associated with deforestation in Brazil

Answer: (c)

  • Which of the following is NOT a major oil-producing zone in the world?

(a) Gulf of Mexico

(b) Persian Gulf

(c) North Sea

(d) Great Lake region of North America

Answer: (d)

  • A decline in a country’s crude birth rate would result in an increase in the country’s

(a) Total fertility rate

(b) Doubling time

(c) Crude death rate

(d) None of the above

Answer: (b)

Explaination: With the decrease in the birth rate, the doubling time decreases. Developed countries have greater doubling time compared to developing countries. In general a country having lower birth rate have lower mortality rate. Decrease in birth rate leads to decrease in total fertility rate.

  1. Which of the following three rivers of Peninsular India have the Amarkantak region as their source

(a) Chambal, Betwa, Sind

(b) Narmada and Subarnarekha

(c) Narmada and Sone

(d) Narmada, North Koel and Baitarani

Answer: (c)

Explaination: Narmada, the largest west flowing river of the Peninsula, rises near Amarkantak range of mountains in Madhya Pradesh. It is the fifth largest river in the country and the largest one in Gujarat. It traverses Madhya Pradesh, Maharashtra and Gujarat and meets the Gulf of Cambay. It is one of only three major rivers in peninsular India that run from east to west (longest west flowing river), along with the Tapti River and the Mahi River. It is one of the rivers in India that flows in a rift valley, flowing west between the Satpura and Vindhya ranges.

Sone River of central India is the second largest of the Ganges’ southern tributaries after Yamuna River. It originates near Amarkantak in Madhya Pradesh, just east of the headwater of the Narmada River, and flows north-northwest through Madhya Pradesh state before turning sharply eastward where it encounters the southwest-northeast-Kaimur Range. The Sone parallels the Kaimur hills, flowing east-northeast through Uttar Pradesh, Jharkhand and Bihar states to join the Ganges just west of Patna.