Deserts, Volcanoes, Waterfalls & Important Geographical Data MCQs
Solved MCQs on world deserts, active volcanoes, famous waterfalls and geographical iso-line terms — Sahara, Antarctica, Angel Falls, Mt. Etna, isobar, isohyet & more. Free quiz + PDF for PPSC, FPSC, NTS, CSS, PMS.
The Sahara Desert (~8.4 million km²) is the world’s largest hot desert, spanning Algeria, Chad, Libya, Mauritania, Sudan, Tunisia, Egypt and Morocco.
Antarctica (~13.6 million km²) is technically the world’s largest desert overall — a cold desert.
The Australian Desert (~1.55 million km²) includes the Great Victoria and Simpson Deserts.
The Arabian Desert (~1.3 million km²) covers southern Arabia, Iraq and Yemen.
The Gobi Desert (~1.04 million km²) lies across Mongolia and China.
The Kalahari Desert (~520,000 km²) is located mainly in Botswana.
The Thar Desert (~260,000 km²) spans northwestern India and Pakistan.
The Atacama Desert (~180,000 km²) in northern Chile is considered the driest non-polar desert on Earth.
Taklamakan Desert (~320,000 km²) lies in Sinkiang (Xinjiang), China.
The Sonoran Desert (~310,000 km²) spans Arizona, California (USA) and Mexico.
The Namib Desert (~310,000 km²) runs along the coast of Namibia.
Kara Kum (~270,000 km²) is the desert of Turkmenistan.
Dasht-e-Lut (~52,000 km²) lies in eastern Iran.
Ojos del Salado (Argentina–Chile) is the world’s highest active volcano.
Mt. Etna in Italy is one of the world’s most continuously active volcanoes.
Mt. Pinatubo in the Philippines had its major eruption in 1991, one of the 20th century’s largest.
Mauna Loa in Hawaii is the world’s largest active volcano by volume.
Klyuchevskaya Sopka in Russia is the highest active volcano in Eurasia.
Mt. Erebus in Antarctica is the southernmost historically active volcano on Earth.
Angel Falls (Venezuela), on the River Carrao, is the world’s highest waterfall at 3,212 feet.
Tugela Falls in South Africa (Natal) is the world’s second-highest waterfall at 3,110 feet.
Niagara Falls, on the USA–Canada border, is only 147 feet high but famous for its huge water volume.
Yosemite Falls in California, USA, stands at 2,425 feet.
Sutherland Falls on the Arthur River in New Zealand is 1,904 feet high.
An Isobar is a line connecting points of equal atmospheric pressure.
An Isohyet is a line connecting points of equal rainfall.
An Isohel is a line connecting points of equal sunlight.
An Isobath is a line connecting points of equal underwater depth.
An Isohaline is a line connecting points of equal salinity.
An Isallobar is a line connecting points of equal change in barometric pressure.
Which is the world's largest hot desert?
The Sahara Desert (~8.4 million km²) is the world's largest hot desert, spanning Algeria, Chad, Libya, Mauritania, Sudan, Tunisia, Egypt and Morocco.
Which continent is technically classified as the world's largest desert?
Antarctica (~13.6 million km²) is a cold desert and is technically the largest desert in the world by area.
The Thar Desert lies between which two countries?
The Thar Desert (~260,000 km²) spans northwestern India and Pakistan.
Which desert is considered the driest non-polar desert on Earth?
The Atacama Desert (~180,000 km²) in northern Chile is widely considered the driest non-polar desert on Earth.
The Gobi Desert is located in which two countries?
The Gobi Desert (~1.04 million km²) lies across Mongolia and China.
The Kalahari Desert is mainly located in which country?
The Kalahari Desert (~520,000 km²) is located mainly in Botswana.
Taklamakan Desert is situated in which region?
The Taklamakan Desert (~320,000 km²) lies in Sinkiang (Xinjiang), China.
The Sonoran Desert spans which countries?
The Sonoran Desert (~310,000 km²) spans Arizona and California (USA) and Mexico.
The Namib Desert runs along the coast of which country?
The Namib Desert (~310,000 km²) runs along the coast of Namibia.
Kara Kum desert is located in which country?
Kara Kum (~270,000 km²) is the desert of Turkmenistan.
Which desert lies in eastern Iran?
Dasht-e-Lut (~52,000 km²) lies in eastern Iran and is one of the hottest places on Earth.
The Mojave Desert is located in which region?
The Mojave Desert (~35,000 km²) is located in Southern California, USA.
Which desert lies in the Arabian Peninsula, Iraq and Yemen?
The Arabian Desert (~1.3 million km²) covers southern Arabia, Iraq and Yemen.
Which is the world's highest active volcano?
Ojos del Salado, on the Argentina–Chile border, is the world's highest active volcano.
Mt. Pinatubo, known for one of the 20th century's largest eruptions, is located in which country?
Mt. Pinatubo in the Philippines erupted in 1991 — one of the largest volcanic eruptions of the 20th century.
Which active volcano is located in Italy and erupts continuously?
Mt. Etna in Italy is one of the world's most active and continuously erupting volcanoes.
Mauna Loa, the world's largest active volcano by volume, is located in which US state?
Mauna Loa in Hawaii is the largest active volcano on Earth by volume.
Which volcano is the highest active volcano in Eurasia?
Klyuchevskaya Sopka in Russia (Kamchatka Peninsula) is the highest active volcano in Eurasia.
Mt. Erebus, the southernmost historically active volcano, is located on which continent?
Mt. Erebus in Antarctica is the southernmost historically active volcano on Earth.
Popocatepetl, a steaming volcano, is located in which country?
Popocatepetl is located in Mexico and remains one of the country's most closely monitored volcanoes.
Which is the world's highest waterfall?
Angel Falls, on the River Carrao in Venezuela, is the world's highest waterfall at 3,212 feet.
Tugela Falls, the world's second-highest waterfall, is located in which country?
Tugela Falls in Natal, South Africa, is the world's second-highest waterfall at 3,110 feet.
Niagara Falls lies on the border of which two countries?
Niagara Falls lies on the border of the USA and Canada. Though only 147 feet high, it is famous for its massive water volume.
Yosemite Falls, standing at 2,425 feet, is located in which US state?
Yosemite Falls in California, USA, stands at 2,425 feet and is one of the tallest waterfalls in North America.
Sutherland Falls, on the Arthur River, is located in which country?
Sutherland Falls in New Zealand, on the Arthur River, stands at 1,904 feet.
What does an 'Isobar' connect on a map?
An Isobar is a line connecting points of the same atmospheric pressure — commonly seen on weather maps.
What does an 'Isohyet' represent?
An Isohyet is a line connecting points of equal rainfall.
What does an 'Isohel' connect?
An Isohel is a line connecting points of equal sunlight.
What does an 'Isobath' represent on a map?
An Isobath is a line connecting points of equal underwater depth, used in bathymetric (seabed) mapping.
What does an 'Isohaline' connect?
An Isohaline is a line connecting points of equal salinity, commonly used in oceanography.
What does an 'Isallobar' represent?
An Isallobar is a line connecting points of equal change in barometric pressure over a given time.
Deserts, Volcanoes, Waterfalls & Geographical Data — Complete Reference
This topic covers four exam-favourite areas of World Geography Part I — Physical Features: the world’s major deserts by area and territory, active and historically significant volcanoes, the world’s tallest waterfalls, and the specialised iso-line terms examiners frequently test (isobar, isohyet, isohel and more). These facts appear regularly in PPSC, FPSC, NTS, CSS, PMS, OTS and CTS General Knowledge papers. For the rest of the physical-features category, see our World Geography Hub.
World’s Major Deserts — Area & Territories
| Desert | Area (km²) | Territories |
|---|---|---|
| Antarctica | 13,600,000 | Whole Antarctica — world’s largest cold desert |
| The Sahara | 8,400,000 | Algeria, Chad, Libya, Mauritania, Sudan, Tunisia, Egypt, Morocco, etc. |
| Australian Desert | 1,550,000 | Australia — Great Victoria, Simpson, etc. |
| Arabian Desert | 1,300,000 | Southern Arabia, Iraq, Yemen |
| The Gobi | 1,040,000 | Mongolia and China |
| Kalahari Desert | 520,000 | Botswana |
| Taklamakan | 320,000 | Sinkiang, China |
| Sonoran Desert | 310,000 | Arizona & California USA, and Mexico |
| Namib Desert | 310,000 | Namibia |
| Kara Kum | 270,000 | Turkmenistan |
| Thar Desert | 260,000 | Northwestern India and Pakistan |
| Somali Desert | 260,000 | Somalia |
| Atacama Desert | 180,000 | Northern Chile |
| Kizil Kum | 180,000 | Uzbekistan–Kazakhstan |
| Dasht-e-Lut | 52,000 | Eastern Iran |
| Mojave Desert | 35,000 | Southern California |
| Desierto de Sechura | 26,000 | North-west Peru |
Volcanoes of the World — Active & Recently Erupted
| Name | Country | Date of Last Eruption |
|---|---|---|
| Ojos del Salado | Argentina–Chile | 1981 — Steams |
| Cotopaxi | Ecuador | 1975 |
| Tupungatito | Chile | 1964 |
| Nevado del Ruiz | Colombia | 1985 |
| Klyuchevskaya Sopka | Russia | 1974 |
| Mauna Loa | Hawaii | 1978 |
| Mt. Cameroon | Cameroon | 1959 |
| Rindjiani | Indonesia | 1966 |
| Semeru | Indonesia | 1976 |
| Mt. Etna | Italy | Active |
| Mt. Pinatubo | Philippines | 1991 |
| Guallatiri | Chile | 1960 |
| Lascar | Chile | 1968 |
| Popocatepetl | Mexico | 1920 — Steams |
| Sangay | Ecuador | 1976 |
| Purace | Colombia | 1977 |
| Tacana | Guatemala | Rumbles |
| Erebus | Antarctica | 1975 |
| Pico de Teide | Spain | 1909 |
| Nyirangongo | Zaire | 1977 |
| Mt. Unzen | Japan | 1991 |
| Andaman | India | Active |
Note: eruption years above reflect the reference dataset used for MCQ revision. For current volcanic activity status, always cross-check with a live source such as the Smithsonian Global Volcanism Program before an exam.
World’s Famous Waterfalls — Ranked by Height
| # | Name | Location | Country | Height |
|---|---|---|---|---|
| 1 | Angel Falls | River Carrao | Venezuela | 3,212 feet |
| 2 | Tugela | Natal | South Africa | 3,110 feet |
| 3 | Tres Hermanas | Catarata | Peru | 3,000 feet |
| 4 | Olo’upena Falls | — | California, USA | 2,953 feet |
| 5 | Yumbilla | Catarata | Peru | 2,938 feet |
| 6 | Yosemite | — | California, USA | 2,425 feet |
| 7 | Sutherland Falls | Arthur River | New Zealand | 1,904 feet |
| 8 | King George VI | Utshi | Guyana | 1,600 feet |
| 9 | Browne Falls | Wallinton | New Zealand | 2,744 feet |
| 10 | Niagara | Niagara | USA and Canada | 147 feet |
Important Geographical Data — Iso-Line Terms
An iso-line connects points of equal value on a map. Examiners frequently test which term matches which measurement — memorise these carefully as several look similar.
| Term | Definition |
|---|---|
| Isallobar | Line connecting points of equal change in barometric pressure |
| Isobar | Line connecting points of same atmospheric pressure |
| Isobath | Line connecting points of equal underwater depth |
| Isobront | Line connecting points of simultaneous storm development |
| Isochar | Line connecting points of similar distinguishing plant-life characteristics |
| Isochor | Line connecting points of varying conditions under constant volume |
| Isograph | Line connecting points of same linguistic usage in some respect |
| Isohaline | Line connecting points of equal salinity |
| Isohel | Line connecting points of equal sunlight |
| Isohyet | Line connecting points of equal rainfall |
| Isoline | Line connecting points on a map having some similar feature |
| Isometric | Line connecting points of equal variation of pressure |
| Isopleth | Line connecting points of equal aspect of climate |
| Isopor | Line connecting points of equal annual change in magnetic field |
For further reading, see Wikipedia’s Desert entry and the USGS Volcano Hazards Program.