Consider the following statements with reference to earthquakes: 1. Collapse earthquakes are most common. 2. Tsunamis are waves generated by the tremors and not an earthquake in itself. 3. High magnitude earthquakes i.e. 8+ are quite rare whereas 'tiny' types occur almost every minute. Which of the statements given above are correct?
- A.1 and 2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
Correct answer
Explanation
The correct answer is C, 2 and 3 only. Statement 1 is false because tectonic earthquakes, not collapse earthquakes, are the most common type.
Earthquakes are grouped by cause: tectonic (sliding of rocks along a fault), volcanic, collapse (the roofs of underground mines or caverns falling in), explosion (from nuclear or chemical blasts) and reservoir-induced. Collapse earthquakes are small and local, while tectonic ones are by far the most frequent and the most destructive. A tsunami is a series of sea waves set off when the sea floor is shaken by an undersea quake; it is an effect of the tremor, not an earthquake itself. Great quakes of magnitude 8 or more happen about once a year, while tiny tremors too weak to feel occur almost every minute somewhere on Earth.
A is wrong because it includes the false statement 1 and leaves out statement 3. B is wrong because it includes statement 1 and leaves out statement 2. D is wrong because statement 1 is false.
Exam tip: the most common earthquakes are tectonic; collapse quakes occur in mining areas; a tsunami is an effect of an earthquake.
Practice Questions
View allD performs her train journey by the shortest route from Bengaluru to New Delhi. Which one of the following rivers will she not cross while performing the journey?
- A.Narmada
- B.Yamuna
- C.Godavari
- D.Krishna
Show answer
The shortest rail route from Bengaluru reaches Delhi from the south through Agra and Mathura, which lie on the western side of the Yamuna, so the train never has to cross that river.
Read the full explanation →In India, the period of steady population growth refers to the decade(s) of:
- A.1981-2011
- B.1951-1981
- C.1921-1951
- D.1911-1921
Show answer
In the standard division of India's population history, the three decades from 1921 to 1951 are called the period of steady population growth.
Read the full explanation →With reference to earthquakes, which of the following statements are correct?
1. Earthquakes largely occur along the converging plate boundaries.
2. Point of origin of earthquake in lithosphere is known as focus/hypocentre.
3. Intensity of earthquake decreases with distance from the epicentre.
4. Epicentre of earthquake always remains over continents only.
Select the correct answer using the code given below.
- A.1 and 2 only
- B.1, 2 and 3
- C.2 and 3 only
- D.1 and 4
Show answer
The first three statements are true, while statement 4 is false because many earthquakes have their epicentre under the sea.
Read the full explanation →National Disaster Management Authority is headed by
- A.the Prime Minister.
- B.the Home Minister.
- C.the President.
- D.the Health Minister.
Show answer
Under the Disaster Management Act, 2005, the Prime Minister is the ex officio chairperson of the National Disaster Management Authority (NDMA).
Read the full explanation →Which of the following statements related to the stages of evolution of the present atmosphere are correct?
1. The first stage is marked by the loss of primordial atmosphere.
2. In the second stage, the hot interior of the earth contributed to the evolution of the atmosphere.
3. Finally, the composition of the atmosphere was modified by the living world through the process of photosynthesis.
Select the answer using the code given below:
- A.1 and 2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
Show answer
All three statements describe, in the right order, the three stages through which the present atmosphere of the Earth evolved.
Read the full explanation →