TEMPERATURE
TEMPERATURE
➢ This is the degree of hotness or coldness of a body at a particular time.
o It is denoted latter “T’’
o SI – Unit of temperature is Kelvin {k}
THERMOMETER
➢ This is an instrument used to measure temperature of a body.
However the SI – Unit of temperature is Kelvin (K) but the degree Celsius (0C) is very commonly used.
The zero Kelvin (0k) is equal to −2730C and zero Celsius (00C) is equivalent to 273K.
The Kelvin (K) is usually referred to as the absolute zero.
STRUCTURE OF A THERMOMETER
MEASUREMENT OF TEMPERATURE
Temperature is measured using a thermometer.
A common example of thermometer is Liquid – in – glass thermometer.
This thermometer contains a liquid, usually mercury or coloured alcohol, which expands or contracts as its temperature changes.
❖ Example of liquid in glass thermometers are:
1) Clinical thermometer
2) Maximum and minimum thermometer
▪ Other examples of thermometers are thermister thermometer and thermocouple thermometer.
PHYSICAL PROPERTIES THAT CHANGE WITH TEMPERATURE
❖ Physical properties that change with temperature can be shown by using different liquids that is mercury or alcohol basis on their properties.
❖ Physical properties that change with temperature are:
1) Volume of a liquid
2) Resistance of a liquid
3) Electrical properties of a liquid
Generally, every thermometer depends on some physical property of a material that varies with temperature.
For example;
• A liquid – in – glass thermometer depends on the volume of the liquid.
• Thermistor thermometer depends on the electrical properties of materials varying with temperature.
FULL NOTES
