Physics: Heat & Temperature (Prt1)

Temperature & Thermometers

Temperature

an object that’s measure of the hotness of that object

What’s the SI units?

What’s an advantage of a Kelvin?

The Kelvin, absolute zero (on the Kelvin scale) corresponds to -273.15 °C and consider a difference in temperature of 1K to be equivalent to a difference in temperature of 1°C

It’s always positive

Thermocouple

is comprised of two different metals joined together at both ends to form two junctions

Examples of thermometric property

• Length of a column of liquid. E.g. Mercury & alcohol thermometers

• Electrical resistance

• Colour changing stripes

• Emf of a thermocouple

Give the equation of temperature on the Celsius scale?

θ/°C=T/K-273.15

Why do we need to have a standard thermometer?

Two different types of thermometer may have different temperature readings at the same level of hotness.

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A good thermometer has a low heat capacity, meaning it doesn’t take much heat from the object whose temperature is being measured. Also, it’s helpful if the thermometer changes quickly in response to a temperature change and is very sensitive.