Which of the following statements is/are correct? 1. The time at 180° longitude is exactly 12 hours from the 0° longitude, irrespective of whether one travels westward or eastward from the Prime Meridian. 2. A person moving eastward on Tuesday will count the day as Wednesday once the International Date Line is crossed. Select the answer using the code given below.
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Correct answer
Explanation
The correct answer is A, 1 only. Statement 1 is right, but statement 2 has the date change the wrong way round.
The Earth turns 360° in 24 hours, so every 15° of longitude means one hour of time. The 180° meridian is 180 ÷ 15 = 12 hours away from Greenwich in either direction: 12 hours ahead if you go east and 12 hours behind if you go west. The International Date Line runs roughly along this meridian, and the date changes when you cross it. A traveller moving east across the line goes back one day, while a traveller moving west goes forward one day. So a person moving eastward on Tuesday would count the day as Monday, not Wednesday.
B is wrong: statement 2 is incorrect, as shown above.
C is wrong: both cannot be correct because statement 2 is false.
D is wrong: statement 1 is correct, so "neither" does not fit.
Exam tip: Crossing the Date Line eastward, repeat a day (lose a date); westward, skip a day (gain a date). 15° = 1 hour, 1° = 4 minutes.
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 →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
Show answer
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.
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 →