WBBSE Solutions For Class 6 Geography Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time

WB Class 6 Geography Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Analytical Type Questions

Question 1. What is International Date Line? What are the characteristics of this line?
Answer:

The International Date Line:

The International Date Line is an imaginary line that follows the 180° longitude mostly but deviates from its original position near the Aleutian Islands, Fiji, and the Chatham Islands.

The International Date Line acts as a division between the dates of the eastern and western hemispheres. According to this line, calendar dates are changed.

Characteristics: The characteristics of the International Date Line are:

1. Enumeration of a calendar date starts and ends at this line.

2. When we cross the International Date Line from east to west, we gain a day and the reverse happens when we cross it from west to east.

3. To manage the confusion of local time in matters of administration or trade and business, the International Date Line has been imagined over water and not over any landmass except Antarctica.

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Question 2. What is standard time?
Answer:

Standard time:

The time in any country, standardized according to the local time at its Standard Meridian or the line of longitude passing through the middle of that country, is called the standard time of that country.

This is done primarily for the convenience of administration and governance. Generally, a country has one standard time based on its Standard Meridian.

WB Class 6 Geography Question Answer

But some countries have several standard times, that divide the country into different time zones.

In India, the 82°30’E longitude, passing over Allahabad (now Prayagraj) is the Standard Meridian and its local time is known as the Indian Standard Time (1ST).

Bangladesh considers the 90°20’E meridian passing over Dhaka as its Standard Meridian and calculates the standard time accordingly.

 

Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Short Analytical Type Questions

Question 1. Why did the last date of Ferdinand Magellan’s expedition not match with the calendar?
Answer:

The last date of Ferdinand Magellan’s expedition not match with the calendar:

Ferdinand Magellan set off on an expedition to circumnavigate the Earth in 1519. When the crew returned to the home port after 3 years, they found that the date of return on their calendar did not match the country’s calendar date.

The reason for this was, as they had crossed the International Date Line towards the east, they should have added 1 day to their calendar, which they did not.

Since they gained a day by crossing the International Date Line towards the east, which they did not notice, their calendar date did not match with the country’s calendar date.

Question 2. What will happen if you move in an airplane or a ship in the same or opposite direction of the rotation of the Earth?
Answer:

The following are the likely conditions while traveling:

1. If we move in the same direction as the Earth rotates i.e. from west to east: We will gain time if we move from west to east. But as soon as we cross the International Date Line and enter the western hemisphere, we need to subtract a day from our calendar.

2. If we move in the opposite direction of the Earth’s rotation i.e. from east to west: We will lose time if we move from east to west.

But as soon as we cross the International Date Line and enter the eastern hemisphere, we need to add a day to our calendar.

WB Class 6 Geography Question Answer

Question 3. Why does the 180* line deviate as it passes over the Pacific Ocean? Or, Why is the International Date Line deliberately skewed in some parts?
Answer:

The 180° line or the International Date Line is not straight, it is a zigzag line. For instance, it changes course over the following landmasses:

1. The north-eastern part of Siberia;
2. Aleutian Islands, near 7° West;
3. Chatham, Fiji Island group near 11° East.

If the 180° line passes over a country, two different dates on either side of the line will create confusion.

To avoid this, the International Date Line has been deliberately imagined in a zigzag manner so that no confusion arises for administration or trade-related matters.

Question 4. What do you mean by local time?
Answer:

Local time:

The time of a place, determined according to noon time or when the Sun is directly overhead the meridian passing through that place, is called the local time of that place.

The Earth rotates on its axis once every 24 hours, and during the course of this rotation, sunrays fall vertically at different places at different times.

Question 5. What are the differences between local time and standard time?
Answer:

The differences between local time and standard time:

 

Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Short Answer Type Questions

Question 1. Why are places in the east always ahead of time?
Answer:

Places in the east always ahead of time:

The Earth rotates on its axis from west to east. Therefore, places in the east face the Sun before places in the west.

Thus, places in the east see the sunrise, noon, afternoon, evening, and night before those in the west. Thus, places in the east are always ahead of time.

WB Class 6 Geography Question Answer

Question 2. On which side of the international Dateline are the eastern and the western hemispheres located?
Answer:

The western hemisphere is located to the right and the eastern hemisphere is located to the left of the International Date Line.

Question 3. Look at the globe and try to identify the sides of the International Date Line on which you would find the eastern and western hemispheres respectively.
Answer:

I would find the eastern and western hemispheres on the left and right sides of a globe, respectively.

Question 4. What do you mean by am and pm?
Answer:

Am and Pm:

The period of time between 12 midnight and 12 noon at any place refers as am or Ante Meridian and pm or Post Meridian refers to the period of time between 12 noon and before 12 midnight at any place.

Question 5. What is the railway time?
Answer:

Railway time:

Railway time considers the 24-hour clock. So, 3:00 am is shown as 03:00 hours, and 3 pm is shown as 15:00 hours. 12 noon is 12:00 hours and 12 midnight is 00:00 hours.

Question 6. What will be the time in an ordinary watch when the clock in the station displays 20:00 hours? Where else have you seen such a clock?
Answer:

When the clock in the station displays 20:00 hours, in an ordinary watch the time will be 8:00 pm. I have seen such a clock at the airport.

WB Class 6 Geography Question Answer

Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Multiple Choice Questions

Question 1. In Australia, Christmas is celebrated in—

1. Summer
2. Winter
3. Monsoon

Answer: 1. Summer

Question 2. When it is 12 midnight on 1 January in Australia, in the USA it is—

1. 31 December evening
2. 31 December morning
3. 1 January night

Answer: 2. 31 December morning

1. Question 3. New year in India is celebrated in—
2. Summer
3. Winter
4. Monsoon

Answer: 2. Winter

Question 4. The international date line is the—

1. 0° Meridian
2. 90° Meridian
3. 180° Meridian

Answer: 3. 180° Meridian

WB Class 6 Geography Question Answer

Question 5. Local time is calculated according to the—

1. 12 Noon at the location
2. 12 Midnight at the location
3. Morning 6 o’clock at the location

Answer: 1. 12 Noon at the location

Question 6. The term ‘meridian’ comes from—

1. Latin word
2. Greek word
3. German word

Answer: 1. Latin word

Question 7. The meridian passing through the middle of the geographical boundary of a country is called its—

1. Local meridian
2. Standard meridian
3. Mean meridian

Answer: 2. Standard meridian

Question 8. The standard meridian passing through India is—

1. 88°30’E
2. 82°30’E
3. 77°12’E

Answer: 2. 82°30’E

Question 9. India’s standard time is calculated according to the line of longitude passing through—

1. Kolkata
2. Allahabad
3. Delhi

Answer: 2. Allahabad

Question 10. If the railway station clock reads 20:00 hours, it means—

1. Morning 8 o’clock
2. Evening 8 o’clock
3. Morning 10 o’clock

Answer: 2. Evening 8 o’clock

Class 6 Geography WBBSE

Question 11. If it shows 00:00 hours on the airport time display, it is then—

1. 12 Noon
2. 12 Midnight
3. Morning 6 o’clock

Answer: 2. 12 Midnight

Question 12. From 12 midnight to 12 noon, the time period is called—

1. Post meridian
2. Ante meridian
3. Meridian

Answer: 2. Ante meridian

Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Fill In The Blanks

Question 1. Ferdinand Magellan set out on the first expedition to circumnavigate the Earth in the year____________
Answer: 1519

Question 2. A date starts or ends at____________
Answer: International dateline

Question 3. The country in which you live is in the ____________ hemisphere.
Answer: North-eastern

Question 4. When the Sun is directly overhead any meridian, it is ____________ at all places on that meridian.
Answer: Noon

Question 5. A line of ____________ is also called a meridian.
Answer: Longitude

Question 6. If the meridian changes,____________ time changes.
Answer: Local

Question 7. The time at India’s ____________ meridian is considered as Indian Standard Time.
Answer: 82º30’E

Question 8. If the departure time on your railway ticket says 12:00 hours, it means your train will leave at 12 ____________
Answer: Noon

Question 9. If the time according to any digital watch is 23:00 hours, then the time is ____________
Answer: 11 pm

Class 6 Geography WBBSE Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Write True Or False

Question 1. 1The International Date Line is 180° longitude.
Answer: True

Question 2. If we cross the International Date Line from the west to the east, we lose a day.
Answer: False

Question 3. A change in longitude means a change in local time.
Answer: True

Question 4. Noon time at any place means 1 pm local time that place.
Answer: False

Question 5. Lines of longitude are also called meridians.
Answer: True

Question 6. The Standard Meridian of India is 82°30’E.
Answer: True

Question 7. Japan is called the Land of the Rising Sun.
Answer: True

Question 8. If we travel from west to east, we lose a day.
Answer: False

Question 9. The time period from 12 midnight to 12 noon is called am (Ante Meridian).
Answer: True

Class 6 Geography WBBSE Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Match The Columns

Answer: 1-C,2-F,3-D,4-E,5-A,6-B,7-C

Class 6 Geography WBBSE Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Answer In One Or Two Words

Question 1. From which year did the 180* meridian become the International Date Line?
Answer: 1884.

Question 2. Where does the International Date Line deviate to the east?
Answer: Aleutian Islands.

Question 3. How many time zones are there in the USA?
Answer: 4 time zones.

Question 4. Write the full form of pm.
Answer: Post Meridian.

Question 5. Which country is called the ‘land of the rising Sun7?
Answer: Japan.

Question 6. What is the value of the Standard Meridian of the world?
Answer: 0º.

Question 7. What is the full form of GMT?
Answer: Greenwich Mean Time.

 

Chapter 4 Rotation Of The Earth Topic B International Date Line And Local Time Miscellaneous Type Questions Find The Odd One Out

Question 1. Dawn: Morning: Noon: Midnight
Answer: Midnight (there is no daylight)

Question 2. Local Time: Standard Time: American Standard Time: Greenwich Mean Time
Answer: American Standard Time (this is not globally recognized)

Question 3. Equator: Prime Meridian: 20° East longitude: International Date Line
Answer: Equator (not a longitude)

Question 4. Equator: Tropic of Cancer: Arctic Circle: International Date Line
Answer: International Date Line (not a latitude)

Class 6 Geography Question Answer WBBSE Correct The Following

Question 1. A day does not change as a person crosses the International Date Line.
Answer: Date changes

Question 2. 0° longitude is known as the International Date Line.
Answer: Prime Meridian

Question 3. The first scientist to talk about gravitational force was Magellan.
Answer: Prime Meridian

Question 4. Newton discovered that the Sun is in the center of the solar system.
Answer: Copernicus

Class 6 Geography Question Answer WBBSE Who Am I?

Question 1. I am a certain motion of the Earth, that results in sunrise and sunset on Earth. Who am I?
Answer: Rotation

Question 2. It is because of me that you do not fly off the Earth’s surface even though the Earth is in constant motion. Who am I?
Answer: Gravitational Force

Question 3. I am the imaginary line along which the Earth is divided into a lit-half and a dark half. Who am I?
Answer: Circle of illumination

Question 4. It seems that the Sun rises in the east and sets in the west every day because of me. Who am I?
Answer: Apparent Daily Motion of the sun

Question 5. I am the imaginary line according to which calendar dates are determined. Who am I?
Answer: International dateline

Question 6. In any nation, I am the meridian that decides the country’s standard time. Who am I?
Answer: Standard meridian

Question 7. I am the mellow light that is seen after sunset. Who am I?
Answer: Dusk

Class 6 Geography Question Answer WBBSE Scrambled Words

1. PERCUSSION
2. DOWCIRSHACLE
3. VIGRATITAON
4. MERCANTILE

Answer:

1. COPERNICUS
2. SHADOW CIRCLE
3. GRAVITATION
4. LOCAL TIME

 

Class 6 Geography Question Answer WBBSE Fill Up The Blanks In The Knowledge Hive

Question 1. Fill In The Knowledge Hive With Information On The International Date Line

Answer:

1. This almost follows the 180° longitude.
2. The calculation of a new date starts from this line.
3. A person gains a day when this line is crossed from west to east.
4. A person loses a day when he crosses this line from east to west.
5. This line has been deliberately skewed in some parts to avoid confusion.

Class 6 Geography WBBSE Advanced Questions And Answers

Question 1. Why we do not feel the rotational movement of the earth?
Answer: We, the creatures living on Earth, do not feel the rotational movement of the Earth because of the following reasons:

1. Everything on Earth is rotating along with the Earth itself. We are also rotating along with the Earth at the same pace.

2. Our size is insignificant in relation to the Earth’s vast extent of 510 million sq. km.

3. Nothing on the Earth’s surface moves against the Earth’s rotational direction. The wind systems, and ocean currents, all move from west to east.

4. The rotational force is stable, unchanging, and pre-determined.

Thus, we do not feel the Earth’s movement. Instead, we see the Sun’s apparent movement, i.e. it rises in the east and sets in the west. However, the Sun is stationary and the Earth rotates around it.

Question 2. Why all places on Earth do not receive v the same amount of light?
Answer: The Earth rotates from west to east, and consequently, the side facing the Sun experiences day, and the opposite side experiences night.

The Earth is tilted at an angle of 661/2° with its orbital plane. Thus the equatorial regions get vertical sun rays and the polar regions get slanting rays of the Sun.

Moreover, the regions which are receiving sunlight, get more rays at noon when the Sun is overhead, and less during the morning and afternoon.

 

Formative

Participation: This segment will indicate how much the students have actively participated and taken initiative during the class.

Question 1. Starting from points A, B, and C and running along the circular paths on which each point is located, three people should come back to their starting points at the same time. Who do you think has to be the quickest to do this? Who can afford to be the most sluggish?

Answer:

The circumference of the circle of point A is the smallest, and the circumference of the circle of point C is the biggest.

Since the race has to be completed at the same time, the one who runs along the circle line of point C has to run the most quickly and the one who runs along the circle line of point A can afford to be most sluggish.

Question 2. Find the International Date Line on the world map. Make a list of the countries, islands, or groups of islands that first experience a new day or a new year.
Answer:

All the countries, islands, or groups of islands that first experience a new day or a new year,

Are listed below—

Name of the countries:

1. Japan,
2. Russia,
3. Australia,
4. New Zealand,
5. North Korea,
6. South Korea, etc.

Name of the islands:

1. Sakhalin,
2. Taiwan,
3. Guam,
4. Palau,
5. Nauru,
6. Wrangel,
7. Ellis, etc.

Name of the group of islands:

1. Fiji,
2. Chatham,
3. Tonga,
4. Indonesia,
5. Philippines,
6. Marshall,
7. Kuril, etc.

The International Date Line is an imaginary line that follows the 180° longitude mostly but deviates from its original position near the Aleutian Islands, Fiji, and the Chatham Islands.

The International Date Line acts as a division between the dates of the eastern and western hemispheres. According to this line, calendar dates are changed.

 

Characteristics: The characteristics of the International Date Line are:

1. Enumeration of a calendar date starts and ends at this line.

2. When we cross the International Date Line from east to west, we gain a day and the reverse happens when we cross it from west to east.

3. To manage the confusion of local time in matters of administration or trade and business, the International Date Line has been imagined over water and not over any landmass except Antarctica.

Interpretation and Application: This segment will test whether the students have understood the topics,  or whether they are just mugging up.

Question 1. What happens when you spin a top on a table?
Answer:

Spinning a top on a table makes it seem as if there is an invisible axis along the middle of the top, on which the top is rotating. The Earth spins similarly on its axis.

 

Question 2. From a running train, you will see the whole landscape is running in the direction opposite to that of the movement of the train. Why it seems to be so? Does everything outside really run in the opposite direction?
Answer:

Everything outside a running train seems to run in the opposite direction. This is because the train itself seems stationary and the static objects outside seem in motion.

This is similar to the rotation of the Earth. Every day we see the Sun rising in the east and setting down in the west. Actually, the Earth rotates from west to east.

That is why the Sun apparently moves from east to west along the sky, just like in the case of a fast-moving object.

Questioning and Experimentation: This segment will investigate the student’s understanding of the subject, questioning capacity, ability to explain and apply and urge for experimentation.

Question 1. Shubhadeep’s grandma can guess the time without even looking at the clock, during any part of the day. Most of the time her guess is accurate to the hour, if not better. How does she do it?
Answer:

Shubhadeep’s grandma can guess the time of the day by looking at the shadow of the coconut tree.

When grandma goes to the pond early in the morning, she sees a long shadow of the tree falling on the west.

Thus, she realizes it is 6 o’clock in the morning. Then as the day grows longer, the length of the shadow decreases. In the noon, the shadow of the tree is the shortest, thus she can tell it is 12 noon.

In the evening, at sunset, a long shadow falls towards the east. At this time, she can guess it is 5 pm.

In this way, she can correctly guess the accurate hour of the day, though not the minutes or seconds.

Question 2. Think about it. What is the time now? Which place is this time true for?-Your city, your country, or the world?

Does a clock in Chicago, USA, or Tokyo, Japan show the same time that your clock is showing now? What is the date today? Which place is this date true for?—

Your city, your country, or the world? Where on Earth does a new day begin first?
Answer:

A sample answer for the aforesaid questions is given below—

Question 3. How long do you sleep at night? How long do you take to dress up for school? How much time did the champion take to complete the 100 m race in your school sports?—Keep an eye on what unit of time (hour/minute/second) you are using to answer these questions.
Answer:

A sample answer for the aforesaid question is given—

1. I sleep 8 hours at night.
2. It takes 25 minutes to get dressed for school.
3. The winner of the 100 meters race in school finished his race in 20 seconds.
4. Here, I use hours to calculate the sleeping time, minutes, and seconds to calculate the time taken to dress up and finish the race respectively.

Aesthetics and Creativity: This segment will check the aesthetic sense and creativity of the students.

Question 1. Prove the formation of days and nights with an experiment.
Answer:

Formation of day and night can easily be proven by pointing a torch light towards a globe.

Materials required: A globe, A bright torch, or a candle

Experiment: A dark room has to be created by shutting all the doors and windows of a room. On one side of the globe, a torch or a candle is placed on the table. Now we have to rotate the globe from the west to the east.

Observation: The candle lights up the side of the globe facing it. With the completion of one full rotation, it can be observed that a particular place that was facing the light enters the dark side and vice-versa.

Inference: This can be compared to the formation of day and night on Earth. The area which is Formation of day and night light experiences day and the area under darkness experiences night.

The area with dim light from darkness to brightness and from brightness to darkness are dawn and dusk respectively.

Question 2. Fix a position on the roof or at any other place that receives a lot of unobstructed sunlight. Stand in that position at every hour of the day.

Observe the direction in which your shadow is cast and also its length. Note down the times of the day when your shadow appears the longest and the shortest.

Answer:

I fix a place on the roof where the Sun is shining. I stand at a particular place at every hour of the day. In the morning, I see my shadow grow long and it falls on the west.

Then I notice that the length of the shadow gradually decreases every hour. At 12 noon, I see that my shadow falls under my feet, which is the shortest length of the shadow. Thereafter, I see that the length of the shadow increases again every hour.

The shadow gradually moves towards the east. Just before sunset, the length of the shadow is the longest, just like the length in the morning.

Observing in this way, I see that my own shadow appears to be the longest in the morning and late afternoon and shortest at 12 noon.