The question asks about the meridian that the International Date Line (IDL) roughly follows. This requires knowledge of geographical concepts like meridians, the Prime Meridian, and the purpose and location of the IDL.
Correct Option: B) 180° Meridian
The International Date Line (IDL) is an imaginary line on the surface of the Earth, located roughly at \(180^\circ\) longitude, that separates two consecutive calendar days. Understanding how the date changes when crossing this line is crucial for competitive exams.
Correct Option: B) Date advances by one day
The International Date Line (IDL) is an imaginary line on the Earth's surface that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next. Understanding its function and how it relates to time zones is key to answering this question.
Understanding the International Date Line (IDL): The IDL generally follows the 180° longitude line, with some deviations to accommodate political boundaries. It is where each new calendar day officially begins.
Direction of Travel and Time Zones: The Earth rotates from West to East. This means that places to the East experience sunrise earlier than places to the West. As you travel West across time zones, you typically add an hour for every 15° of longitude. Conversely, as you travel East, you subtract an hour.
Crossing the IDL from West to East: When you cross the IDL from West to East, you are moving into an area where the calendar day is earlier. For example, if it's Monday just West of the IDL, it would be Sunday just East of the IDL. To maintain the correct local time and date, you must adjust your calendar backward.
The Effect: Because you are moving into a region with an earlier date, you effectively repeat a day or "lose a day" from your travel perspective, as you have to set your calendar back by one full day to align with the local date.
Correct Option: D) You lose a day
The question asks about the primary ocean through which the International Date Line (IDL) passes. To answer this, one needs to recall the geographical location and path of the IDL.
C) Pacific Ocean. The International Date Line primarily traverses the Pacific Ocean, making it the correct answer.
The International Date Line (IDL) is an imaginary line on the Earth's surface that runs from the North Pole to the South Pole and demarcates the change of one calendar day to the next. While it largely follows the 180° meridian, it deviates in several places. The reason for these deviations is primarily practical and socio-political, rather than geographical or navigational.
Correct Option: C) To avoid splitting countries and island groups into two different calendar days. This is the primary and most significant reason for the deviations of the International Date Line. The line is adjusted to keep landmasses and island nations on the same side, preventing administrative and social chaos that would arise from having different calendar days within the same political entity or closely related communities.
The question asks for the year in which the International Date Line (IDL) was established by international agreement. This is a factual question related to geographical conventions and historical international conferences.
D) 1884 — The International Date Line was established by international agreement at the International Meridian Conference held in Washington D.C. in 1884.