Which one of the following is classified under the physical processes of weathering?
- A.Water pressure
- B.Oxidation
- C.Carbonation
- D.Hydration
Correct answer
Explanation
The correct answer is A, Water pressure. Pressure of water breaks rock mechanically without changing its minerals, so it is a physical process. Weathering is the breaking down of rocks where they lie. Physical or mechanical weathering splits rock into smaller pieces through forces such as frost wedging, pressure release (unloading), alternate heating and cooling, and the pressure of water seeping into cracks and joints. The rock's chemical make-up stays the same. Chemical weathering, by contrast, changes the minerals themselves through reactions with water, oxygen and carbon dioxide. Option B is wrong because oxidation is a chemical reaction of minerals, especially iron, with oxygen, which gives rocks a rusty colour. Option C is wrong because carbonation is the reaction of carbonic acid with minerals such as calcium carbonate, which dissolves limestone. Option D is wrong because hydration is the chemical addition of water to minerals, which makes them swell and weaken. Exam tip: oxidation, carbonation, hydration and solution are chemical; frost, heat and pressure are physical.
Practice Questions
View allWhich one of the following is not a minor plate ?
- A.Cocos Plate
- B.Nazca Plate
- C.Caroline Plate
- D.Antarctic Plate
Show answer
The Antarctic Plate, carrying Antarctica and the ocean around it, is one of the seven major lithospheric plates. Plate tectonics divides the lithosphere into seven major plates and several minor ones.
Read the full explanation →Which of the following statements with reference to shadow zones in an event of an earthquake is/are correct ? 1. Zone between 105° and 145° from epicentre was identified as the shadow zone for both P-waves and S-waves 2. The shadow zone of P-waves is much larger than that of the S-waves Select the answer using the code given below:
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Show answer
The band between 105° and 145° from the epicentre receives neither P-waves nor S-waves, but it is the S-wave shadow zone that is much larger, so statement 2 is wrong.
Read the full explanation →Which of the following statements about Ring of Fire is/are correct ? 1. It is a zone of convergence plate boundaries 2. It is an active seismic and volcanic zone 3. It is associated with deep trench Select the correct answer using the code given below :
- A.1 and 2 only
- B.2 and 3 only
- C.1 only
- D.1, 2 and 3
Show answer
The Ring of Fire around the Pacific is a belt of convergent plate boundaries, full of active volcanoes and earthquakes and lined by deep ocean trenches.
Read the full explanation →Which one of the following rivers is not a tributary of river Brahmaputra ?
- A.River Manas
- B.River Kameng
- C.River Mahananda
- D.River Subansiri
Show answer
The Mahananda rises in the Darjeeling hills, flows through north Bengal and Bihar and joins the Ganga, not the Brahmaputra.
Read the full explanation →Which of the following statements regarding tropical cyclones is/are correct ? 1. These storms develop during the summer and autumn in every tropical ocean except the South Atlantic and eastern South Pacific Oceans. 2. Tropical cyclones that occur in the North Atlantic and eastern North Pacific Oceans are known as typhoons. 3. Tropical cyclones that occur in the Indian and South Pacific Oceans are called cyclones. Select the answer using the code given below :
- A.3 only
- B.1 and 2 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Tropical cyclones of the North Atlantic and eastern North Pacific are called hurricanes, not typhoons, so statement 2 is wrong.
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