Definition
Tip
Temperature is a reliable measure of the hotness or coldness of a body.
A hotter body has a higher temperature than a colder body. The device used to measure this is called a thermometer.
Scales of Temperature
Just like we measure length in meters or inches, temperature is measured in different scales.
1. Celsius Scale ()
- Most commonly used scale for clinical and laboratory work.
- Unit: degree Celsius.
- Water freezes at and boils at .
2. Fahrenheit Scale ()
- Older scale, still used in some countries.
- Unit: degree Fahrenheit.
- Normal body temperature: .
- Relationship: .
3. Kelvin Scale ()
- Used in scientific work.
- Unit: kelvin (Note: distinct from degrees, we do not write K, just K).
- This is the SI Unit of temperature.
Warning
Writing Tip:
- Celsius/Fahrenheit: Start with capital letters. Units written as degrees ().
- kelvin: The unit starts with a lowercase ‘k’ when written in full, but the symbol is capital K. No degree sign is used.