Q1. Returning to page 10 and to Fig. 5.2 in Chapter 5 of this textbook, taking the scale to be 2.5 cm = 500 km, calculate the real distance from the estuary of the Narmada River to the estuary of the Ganga river.
Answer:
If the distance on the map between the estuary of the Narmada and the Ganga is about 4.5 cm, then using the scale 2.5 cm = 500 km:
5002.5×4.5=900 km2.5500×4.5=900km
So, the real distance is about 900 kilometres.
Q2. Why is it 5:30 pm in India when it is 12 pm or noon in London?
Answer (80–100 words):
The Earth rotates from west to east, and as it rotates, different places experience day and night at different times. The standard time in India is based on the longitude 82.5°E, which is 5 hours 30 minutes ahead of Greenwich Mean Time (GMT) in London. So, when it is 12 noon in London, India is already ahead in time, and the clock here shows 5:30 pm. This is why our watches run 5 hours 30 minutes ahead of London.
Q3. Why do we need symbols and colours in the map?
Answer (50–60 words):
Maps show a lot of information in a small space. It is not possible to draw real shapes of rivers, mountains, roads or buildings. So, symbols are used to represent them clearly. Colours also make maps easy to read — for example, blue for water bodies, green for plains, and brown for mountains. They make maps simple and useful.
Q4. Find out what you have in the eight directions from your home or school.
Answer (student model – about 60 words):
From my school:
- North: A post office
- South: A market
- East: A temple
- West: A bus stop
- Northeast: A playground
- Northwest: A hospital
- Southeast: A small park
- Southwest: A library
(Students can change according to their locality.)
Q5. What is the difference between local time and standard time? (100–150 words)
Answer:
Local time is the time of a particular place based on the position of the Sun. For example, when the Sun is exactly overhead, it is 12 noon at that place. Since the Earth rotates, local time changes as we move east or west. Standard time is a fixed time for an entire country or region, chosen along a central meridian. India uses Indian Standard Time (IST), based on 82.5°E longitude, so that the whole country follows one uniform time. Local time is useful for small areas, but for a big country, standard time avoids confusion in travel, communication and trade.
Q6. Delhi’s and Bengaluru’s latitudes are 29°N and 13°N; their longitudes are almost the same, 77°E. How much will be the difference in local time between the two cities?
Answer:
Since the longitudes are almost the same, both cities have the same local time. The difference will be zero.
Q7. Mark the following statements as true or false; explain your answers with a sentence or two.
-
- All parallels of latitude have the same length. – False. They become smaller as we move towards the poles.
- The length of a meridian of longitude is half of that of the Equator. – True. Longitudes are half circles from pole to pole.
- The South Pole has a latitude of 90°S. – True. It is the farthest point south from the Equator.
- In Assam, the local time and the IST are identical. – False. Assam’s local time is ahead of IST.
- Lines separating the time zones are identical with meridians of longitude. – False. They are adjusted to follow political boundaries.
- The Equator is also a parallel of latitude. – True. It is the longest parallel at 0°.
Q8. Solve the crossword.
Across:
- Scale
- Globe
- Equator
- Greenwich
- Map
- Latitude
Down:
2. Longitude
3. Coordinates
6. Grid
7. IST
9. North Pole
11. IDL
Extra Questions –
Q1. What is the difference between a globe and a map?
Answer:
- A globe is a small model of the Earth that shows its true spherical shape and geographical features.
- A map is a flat drawing of a part or whole of the Earth, showing physical, political, or thematic details.
Globe is best for accuracy of shape; map is best for detailed study.
Q2. Define latitude and longitude.
Answer:
- Latitude: Imaginary lines running east–west, parallel to the Equator, measuring distance north or south of it.
- Longitude: Imaginary lines running north–south from pole to pole, measuring distance east or west of the Prime Meridian.
Q3. Why is the Equator called the “great circle”?
Answer:
The Equator is called the “great circle” because it is the largest circle that divides the Earth into two equal halves — the Northern Hemisphere and the Southern Hemisphere. It is the longest parallel of latitude.
Q4. How are latitudes related to climate?
Answer (70–80 words):
Latitudes influence the climate of different regions. Places near the Equator (low latitudes) are hot and receive direct sunlight (Torrid Zone). The areas in the middle latitudes have moderate or temperate climate. Near the poles (high latitudes), the sunlight is slanting and weak, so these regions are very cold (Frigid Zone). Thus, latitude plays an important role in determining the type of weather and seasons experienced in any place.
Q5. Why was Greenwich chosen as the Prime Meridian?
Answer:
In 1884, an international agreement fixed the Prime Meridian at Greenwich, London, because it was already being used widely by sailors and scientists for navigation. It became the standard reference line for measuring longitude worldwide.
Q6. Explain local time with an example.
Answer (50–60 words):
Local time is the time of a place determined by the position of the Sun. When the Sun is overhead, it is 12 noon at that place. For example, if it is noon in Delhi, the local time in Mumbai may differ slightly because of their different longitudes.
Q7. Why does India use a single standard time?
Answer (70–80 words):
India is a large country with longitudes stretching from Arunachal Pradesh in the east to Gujarat in the west. If every place followed local time, there would be confusion in daily life, travel, and communication. Therefore, the longitude 82.5°E near Allahabad was chosen as the central meridian for Indian Standard Time (IST). This way, the entire country follows one uniform time, 5 hours 30 minutes ahead of Greenwich Mean Time (GMT).
Q8. What is the International Date Line?
Answer:
The International Date Line is an imaginary line at 180° longitude, opposite the Prime Meridian. When we cross it from east to west, we add one day; when we cross from west to east, we subtract one day. It helps to keep the world’s dates in order.