NCERT Solutions Ganita Prakash Chapter 10 Temperature — Figure it Out

Book page 262 Updated on2026-09-05

Q1.
Do you know that there are some places in India where temperatures can go below 0 °C? Find out the places in India where temperatures sometimes go below 0 °C. What is common among these places? Why does it become colder there and not in other places?
Answer

Places in India where the temperature falls below 0 °C:

  • Ladakh — Leh, Kargil, Drass (Drass is one of the coldest inhabited places on Earth, once recording about – 45 °C).
  • Jammu & Kashmir — Srinagar, Gulmarg, Pahalgam.
  • Himachal Pradesh — Keylong, Manali, Spiti, Kalpa.
  • Uttarakhand — Auli, Munsiyari, Badrinath.
  • Sikkim and Arunachal Pradesh — Lachung, Tawang, Sela Pass.

What is common among them: every one of these places is in the Himalayas — high up in the mountains, and in the far north of the country.

Why it gets colder there:
  • Altitude. The air gets thinner and cooler as you go up — roughly 6 °C colder for every 1000 m of height. Leh is about 3500 m up, so it is about 20 °C colder than a plain at the same latitude.
  • Snow. White snow reflects most of the sunlight back instead of absorbing it, so the ground never warms up.
  • Dry, thin air. Whatever little heat the ground gains in the day escapes quickly at night.
  • Latitude. These places are the furthest north in India, so the winter sun stays low and weak.
Math Talk: Discuss in class — is 0 °C ‘no temperature’? No! It is only the mark where water freezes. Temperatures continue below it, just as floors continue below the ground.
Q2.
Leh in Ladakh gets very cold during the winter. The following is a table of temperature readings taken during different times of the day and night in Leh on a day in November. Match the temperature with the appropriate time of the day and night. (14 °C, 8 °C, – 2 °C, – 4 °C with 02:00 a.m., 11:00 p.m., 02:00 p.m., 11:00 a.m.)
Answer

Think about how a day warms up and cools down: coldest just before dawn, warmest in the early afternoon.

TemperatureTimeWhy
14 °C02:00 p.m.Warmest reading — early afternoon, the sun is strongest
8 °C11:00 a.m.Still warming up in the late morning
– 2 °C11:00 p.m.Below freezing at night, but the ground is still losing its heat
– 4 °C02:00 a.m.Coldest reading — the middle of the night, hours after sunset
Order of the four readings: – 4 °C < – 2 °C < 8 °C < 14 °C
Fall from 2 p.m. to 2 a.m.: – 4 – 14 = – 18 °C — the thermometer drops 18 degrees
Why the two negative readings belong to the night: after sunset there is no sunlight to heat the ground, so in a dry, high place like Leh the temperature keeps falling until sunrise. – 4 °C means 4 degrees below the freezing point of water.
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