Question

(i) 0°C (ii) 4°C 17. Draw a diagram showing the temperature of various layers of water in an ice covered pond. со be th transfe chain 3. SL unit of temperature is : (a) cal (c) celsius 18. Explain the following: (a) Water pipes in colder countries often burst in flos winter. (b) joule (d) kelvin 4. Water is cooled from 4°C to 0°C. It: (b) expands (a) contracts (c) first contracts, then expands (d) first expands, then contracts. sy th Ans. (b) In winter, water tank (or ocean) starts freezing from the surface and not from the bottom. (c) Fishes survive in ponds even when the atmospheric temperature is below 0°C. (d) A hollow glass sphere which floats with its entire volume submerged in water at 4°C, sinks when water is heated above 4°C. (e) A glass bottle completely filled with water and tightly closed at room temperature, is likely to burst when kept in the freezer of a refrigerator. 5. Density of water is maximum at : (a) 0°C (b) 100°C (c) 4°C (d) 15°C

​

Answer 1

Answer

• Temperature has three units namely Celsius, Fahrenheit and Kelvin and out of these three the Kelvin scale I internationally recognized and thus it is the S.I. unit.

Answer 2

• The degree of hotness or coldness of a body is called its temperature.
• Temperature can be measured in Celsius scale, Fahrenheit scale and Kelvin scale.
• Kelvin is the SI unit of temperature.