Which one of the following thermometers is known as a pyrometer?

Correct answer: (b) Radiation thermometers

Explanation

A pyrometer is a non-contact radiation thermometer that measures temperature from the infrared radiation emitted by a hot body.

It is ideal for measuring very high temperatures of distant or moving objects, such as furnaces.

Thermo-electric, gas and liquid thermometers are contact-type and unsuitable for such conditions.