What is Temperature? In our everyday life we all listen to a statement “Today the temperature is 23 degree Celsius or 23°C or some other value". Now have you ever asked yourself a question what exactly does temperature means? Let us understand it.
- The intensity of the heat present in any body is known as temperature.
- It is measured using an instrument called Thermometer.
- The unit in which it is measured is Degree Celsius(°C) and the standard unit is Kelvin.(K)
Units and Conversions
There different units to measure the temperature and are listed below:
- Degree Centigrade or Degree Celsius – written as °C.
- Degree Fahrenheit - written as °F.
- Kelvin- written as K.
Kelvin is considered as the SI unit of temperature.
Formula:
Temperature in degree Celsius = 273 - Temperature in Kelvin |
Example 1: Convert 23°C into Kelvin.
Solution: 1°C = 273- Temperature in K
Therefore 1 Kelvin = 273 – 1°C = 272 K.
Conversion from Degree Celsius to Fahrenheit:
The conversion can be done in following 3 steps:
- Multiply the temperature in degree with 9.
- Divide the answer by 5.
- Add 32 to the answer obtained in step 2.
Example 2: Convert 23°C to °F.
Solution: Following the above 3 steps one by one we get,
(23 x 9) = 207 and then
(207 ÷ 5) = 41.4 and then
41.4 + 32 = 71.4°F.
From this figure we can learn two things:
- As the reading of thermometer increases the value of heat increases and hence the body becomes more hot.
- As the reading of thermometer decreases the value of heat decreases and hence the body becomes more cold.
Points to Remember
- The normal temperature of a human body is 37 degree Celsius.
- The Celsius is marked from 0°C to 100°C.
- The Fahrenheit scale is marked from 32°F to 212°F.
- The thermometer used for the medical purpose has a special name Clinical Thermometer.
Practice Question
Q1) What is the normal temperature of a human body?
Q2) At which temperature water starts to boil?
Q3) Convert the following to Degree Fahrenheit.
- 0°C
- 100°C
- 37°C
Q4) State True or False:
- 1°C = 273 K
- Water freezes at 100°C.
- Temperature of ice is 0°C.
Recap
- Thermometer is used to measure temperature of any body.
- Unit of temperature can be K or °C or °F.
- Temperature in °C = 273 – Temperature in K.
- 0°C = 32°F.
- Temperature of ice is 0°C or 32°F.
- Doctors use Clinical Thermometer to measure temperature of patients.